Wireless power station and control method thereof

A power station includes: a plate, a coil below the plate, an inverter configured to supply alternating current power to the coil, a communication module including an antenna and configured to transmit and receive radio signals through the antenna, a display, and a controller configured to control the communication module to communicate with an external device placed on the plate and control the inverter to wirelessly transmit power to the external device through the coil. The controller may control the display to display information indicating whether the external device is aligned with the coil based on a radio signal received from the external device through the antenna.

BACKGROUND

The present application is directed to a wireless power station and a control method thereof, and particularly, to a wireless power station capable of identifying whether a power transmission object is aligned therewith and a control method thereof.

2. Description of Related Art

Recently, technologies for not only wireless communication but also wireless power transmission for wirelessly transmitting power are actively being studied.

In wireless power transmission, power is wirelessly transmitted from a transmitting device to a receiving device according to a magnetic correlation between a transmitting coil of the transmitting device and a receiving coil of the receiving device.

It is known that generally, the efficiency of wireless power transmission is lower than that of wired power transmission. Particularly, it is known that the efficiency of wireless power transmission varies largely according to a relative positional relationship between the transmitting coil and the receiving coil.

To improve the efficiency of wireless power transmission, a magnetic field generated by the transmitting coil should be linked to an inner side of the receiving coil. To link the magnetic field to the inner side of the receiving coil, a center of the transmitting coil and a center of the receiving coil should be aligned with each other.

In the related art, a method of marking a reference position on a transmitting device at which a receiving device is to be positioned or the method of providing a transmitting device with a structure for alignment with a receiving device is used.

However, this method is disadvantageous in that the appearance of the transmitting device is impaired and a use of the transmitting device is limited.

SUMMARY

An aspect of the present disclosure provides a power station capable of identifying whether an electric device is aligned therewith when the electric device is placed on the power station, and a control method thereof.

An aspect of the present disclosure provides a power station capable of identifying whether an electric device is aligned therewith through communication with the electric device during transmission of power to the electric device, and a control method thereof.

An aspect of the present disclosure provides a power station capable of transmitting a message to a user's user device when an electric device is not aligned with the power station, and a control method thereof.

According to an aspect of the present disclosure, a power station includes a plate, a coil below the plate, an inverter configured to supply alternating current power to the coil, a communication module including an antenna and configured to transmit and receive radio signals through the antenna, a display, and a controller configured to control the communication module to communicate with an external device placed on the plate and control the inverter to wirelessly supply power to the external device through the coil. The controller may control the display to display information indicating whether the external device is aligned with the coil based on a radio signal received from the external device through the antenna.

According to an aspect of the present disclosure, a control method of a power station, which includes a plate and a coil below the plate, includes communicating with an external device placed on the plate, displaying whether the external device is aligned with the coil based on a radio signal received from the external device through an antenna, and wirelessly supplying power to the external device through the coil.

According to an aspect of the present disclosure, a power station includes: a plate, a coil below the plate, an inverter configured to supply alternating current power to the coil, a communication module including an antenna and configured to transmit and receive radio signals through the antenna, a display, and a controller configured to control the communication module to communicate with an external device placed on the plate and control the inverter to wirelessly supply power to the external device through the coil. The controller may control the display to display information indicating whether the external device is aligned with the coil based on the amount of power received by the external device.

According to an aspect of the present disclosure, a power station is capable of identifying whether an electric device is aligned therewith when the electric device is placed on the power station. Accordingly, the power station can allow a user to position the electric device at an optimal power transmission position.

According to an aspect of the present disclosure, a power station is capable of identifying whether an electric device is aligned therewith through communication with the electric device during transmission of power to the electric device. Accordingly, the power station can allow a user to position the electric device at an optimal power transmission position when the electric device is moving during an operation of the power station.

According to an aspect of the present disclosure, a power station is capable of transmitting a message to a user's user device when an electric device is not aligned with the power station.

DETAILED DESCRIPTION

The same reference numerals refer to the same elements throughout the specification. The present specification does not describe all elements of embodiments, and a description of general matters in the technical field to which the present disclosure pertain or the same matters in the embodiments will be omitted herein. Terms such as “unit,” “module,” “member,” and “block” used herein may be embodied as software or hardware components, and in some embodiments, a plurality of units, modules, members, or blocks may be embodied together as one component or one unit, module, member or block may include a plurality of components.

Throughout the specification, when an element is referred to as being “connected to” another element, the element should be understood as being connected directly or indirectly to the other element or the indirect connection should be understood to include connection through a wireless communication network.

It will be understood that when an element is referred to as “including” another element, the element may further include other elements rather than excluding the other components unless described otherwise.

Throughout the present specification, when an element is referred to as being “on” another element, it should be understood that the element is in contact with the other element or another element is present therebetween.

Terms such as first and second are used to distinguish one component from another component and components are not limited by these terms.

As used herein, the singular expressions are intended to include plural forms as well, unless the context clearly dictates otherwise.

Reference numerals assigned to operations are used only for convenience of description rather than describing an order of the operations and thus these operations may be performed in an order different from that described above unless the context indicates a specific order.

Hereinafter, a principle of operation of the present disclosure and embodiments thereof will be described with reference to the accompanying drawings.

FIG.1illustrates an appearance of a wireless power station according to an embodiment.FIG.2illustrates an inside of a wireless power station according to an embodiment.FIG.3illustrates an example in which a wireless power station transmits power according to an embodiment.

As shown inFIG.1, a power station100includes a main body101which forms an appearance of the power station100and in which various components of the power station100are installed.

On the main body101, electric devices201and202may be placed. The electric devices201and202may be devices capable of wirelessly receiving power from the power station100. For example, the electric devices201and202may be small household electric appliances, such as an electric kettle, a blender, a toaster, an electric oven, a coffee maker, etc., which may be placed on the main body101of the power station100.

An upper surface101aof the main body101is provided with an upper plate102having a flat shape on which the electric devices201and202may be placed.

A control panel110may be provided at a side of the upper plate102to receive a control command from a user and display operational information of the power station100. However, the control panel110is not limited to being positioned on the upper plate102and may be provided at various locations such as a front surface101band/or a side surface101cof the main body101.

As shown inFIG.2, a plurality of transmitting coils121and122(i.e., transmitting coils120) for supplying power to the electric devices201and202and a circuit board assembly110aimplementing the control panel110may be provided below the upper plate102.

Each of the plurality of transmitting coils121and122may include a wire wound in a roughly helical structure or a spiral form. For example, the transmitting coil120may be formed in a helical structure such that wires are spaced substantially the same distance from each other with respect to a central axis or may be formed spirally such that wires are located on the same plane with respect to a central point.

The transmitting coil120may generate a magnetic field, an electric field, and/or an electromagnetic field to wirelessly supply power to the electric devices201and202.

For example, when a drive current is supplied to the transmitting coil120as shown inFIG.3, a magnetic field B may be induced near the transmitting coil120. Particularly, when a current which changes in strength and direction over time, i.e., an alternating current, is supplied to the transmitting coil120, a magnetic field B that changes in strength and direction over time may be induced near the transmitting coil120.

The magnetic field B induced near the transmitting coil120may pass through the upper plate102and reach the electric devices201and202on the upper plate102.

Each of the electric devices201and202may include a receiving coil220to receive power wirelessly. The receiving coil220may also include a wire wound in a roughly helical structure or a roughly spiral form.

The magnetic field B generated by the transmitting coil120may pass through an inner side of the receiving coil220as shown inFIG.3. A current (hereinafter referred to as an “induced current”) may be induced to the receiving coil220due to the magnetic field B that changes in intensity and direction over time. As such, a phenomenon that an induced current generated due to the magnetic field B changes over time is referred to as an electromagnetic induction phenomenon.

Due to the induced current, the receiving coil220may generate an electromotive force causing a current to flow. Due to the electromotive force of the receiving coil220, power may be supplied to the electric devices201and202, thus operating the electric devices201and202.

As described above, power may be wirelessly transmitted to the receiving coils220of the electric devices01and202through the plurality of transmitting coils121and122using the electromagnetic induction phenomenon.

The plurality of transmitting coils121and122may be aligned in a predetermined pattern below the upper plate102. For example, the plurality of transmitting coils121and122may be arranged in a matrix of rows and columns. In other words, the plurality of transmitting coils121and122may be arranged at a predetermined interval from a front side of the main body101to a rear side thereof and arranged at a predetermined interval from a right side of the main body101to a left side thereof.

The plurality of transmitting coils121and122may include a first transmitting coil121and a second transmitting coil122, and the first transmitting coil121and the second transmitting coil122may be arranged in the same row with respect to a front side of the power station100. However, the arrangement of the plurality of transmitting coils121and122is not limited to that shown inFIG.2, and the plurality of transmitting coils121and122may be arranged in various forms. For example, the first transmitting coil121and the second transmitting coil122may be arranged in the same column with respect to the front side of the power station100.

The circuit board assembly110aimplementing the control panel110may be provided below the control panel110located at a side of the upper plate102. The circuit board assembly110amay be a printed board assembly (PBA) including a printed circuit board (PCB) on which a display, a switch element, an integrated circuit element, etc. implementing the control panel110are installed.

A position of the circuit board assembly110ais not limited to that shown inFIG.2and may be disposed at various positions. For example, when the control panel110is installed on the front surface101bof the main body101, the circuit board assembly110amay be disposed behind the front surface101bof the main body101.

A printed circuit board assembly (not shown) for driving the plurality of transmitting coils121and122may be provided below the plurality of transmitting coils121and122. A driving circuit for supplying a drive current to the plurality of transmitting coils121and122, a control circuit for controlling operations of the plurality of transmitting coils121and122, and the like may be provided on a plurality of printed circuit board assemblies.

As described above, the power station100may include the plurality of transmitting coils121and122for wirelessly transmitting power to the electric devices201and202, the driving circuit for operating the plurality of transmitting coils121and122, and the control circuit.

Similarly, the electric devices201and202may include the receiving coil220for wirelessly receiving power from the power station100, a receiving circuit for processing power received through the receiving coil220, and a control circuit.

Configurations of the power station100and the electric devices201and202will be briefly described below.

FIG.4schematically illustrates configurations of a wireless power station and an electric device according to an embodiment.

As shown inFIG.4, a power station100includes a transmitting coil120, a driver130, a transmission sensor140, a first communicator150, and a transmission controller160. Electric devices201and202each include a receiving coil220, a reception sensor230, a power converter240, an electric load250, a second communicator260, an auxiliary power source270, and a reception controller280.

The transmitting coil120of the power station100may convert electric energy into electromagnetic and/or magnetic energy. In other words, the transmitting coil120may be supplied with an alternating current (an alternating current electric field) and generate an alternating current magnetic field.

The transmitting coil120is magnetically correlated with the receiving coils220of the electric devices201and202. For example, the transmitting coil120and the receiving coil220may be arranged such that an electric field generated by the transmitting coil120may pass through the receiving coil220. The transmitting coil120and the receiving coil220may be formed spirally on a plane, and a central axis of the transmitting coil120and a central axis of the receiving coil220may substantially coincide.

The power station100may further include a resonant capacitor that electrically resonates with the transmitting coil120. Due to a resonance between the resonant capacitor and the transmitting coil120, the transmitting coil120may operate at a frequency for efficiently transmitting power and the efficiency of power transmission by the transmitting coil120may be improved.

The power station100may further include a ferrite element to improve the efficiency of power transmission using a magnetic field B between the transmitting coil120and the receiving coil220. The ferrite element may guide a magnetic field generated by the transmitting coil120toward the electric devices201and202and block a leaking magnetic field.

The power station100may further include an impedance matching circuit to improve the efficiency of power transmission between the transmitting coil120and the driver130.

The driver130may receive power from an external power source ES and supply a current to the transmitting coil120so that power may be wirelessly transmitted through the transmitting coil120under control of the transmission controller160.

The driver130includes an inverter131. The inverter131may include a switch circuit for converting power received from the external power source ES into alternating current power of a predetermined frequency. For example, the inverter131may provide the transmitting coil120with an alternating current that changes in intensity and direction. In addition, the inverter131may change an intensity and/or frequency of an output current to adjust the amount of power to be transmitted from the transmitting coil120to the receiving coil220.

The transmission sensor140includes a transmission current sensor141for sensing a drive current supplied to the transmitting coil120from the inverter131. For example, the transmission current sensor141may include a shunt resistor and measure a potential difference between opposite ends of the shunt resistor. As another example, the transmission current sensor141may include a hall sensor and measure a magnetic field due to a current.

The transmission current sensor141may provide the transmission controller160with an electric signal (e.g., the potential difference between the opposite ends of the shunt resistor or output code of the hall sensor) corresponding to a measured current. The transmission controller160may identify the intensity of a drive current supplied to the transmitting coil120, based on an output signal of the transmission current sensor141, and calculate the amount of power wirelessly transmitted to the electric devices201and202through the transmitting coil120.

The first communicator150may communicate with the electric devices201and202. The first communicator150may include a transmission antenna151provided separately from the transmitting coil120and wirelessly transmit data to or receive data from the second communicators260of the electric devices201and202through the transmission antenna151. For example, for communication efficiency, the transmission antenna151may be formed at an inner or outer side of the transmitting coil120to be concentrically positioned with the transmitting coil120.

The first communicator150may wirelessly transmit data to or receive data from the second communicator260according to various wireless communication standards. For example, the first communicator150may wirelessly transmit data to or receive data from the second communicator260using wireless local area network (LAN) communication or short-range wireless communication.

The transmission controller160may control the driver130to wirelessly supply power to the electric devices201and202based on communication data received from the electric devices201and202through the first communicator150.

For example, the transmission controller160may identify the electric devices201, and202based on the communication data received through the first communicator150. The transmission controller160may receive a request related to power transmission from the electric devices201and202through the first communicator150and control the driver130to adjust an output of the transmitting coil120in response to the received request.

In addition, the transmission controller160may achieve power transmission efficiency according to the communication data received through the first communicator150and identify whether the transmitting coil120and the receiving coil220are aligned with each other based on wireless power transmission efficiency. For example, the transmission controller160may identify whether the electric devices201and202are located at a reference position for alignment of the transmitting coil120and the receiving coil220.

The receiving coils220of the electric devices201and202may convert electromagnetic and/or magnetic energy into electric energy. In other words, the receiving coil220may provide an alternating current (an alternating current electric field) in response to an alternating current magnetic field.

The receiving coil220is magnetically correlated with the transmitting coil120of the power station100. The receiving coil220may output an alternating current and an alternating current voltage from an alternating current magnetic field generated by the transmitting coil120.

The electric devices201and202may further include a resonant capacitor that electrically resonates with the receiving coil220. Due to a resonance between the resonant capacitor and the receiving coil220, the receiving coil220may operate at a frequency for efficiently receiving power and the efficiency of power reception by the receiving coil220may be improved.

The electric devices201and202may further include a ferrite element to improve the efficiency of power reception using a magnetic field B between the transmitting coil120and the receiving coil220. The ferrite element may guide a magnetic field generated by the power station100toward the receiving coil220and block a leaking magnetic field.

The electric devices201and202may further include an impedance matching circuit to improve the efficiency of power transmission between the receiving coil220and the power converter240.

The reception sensor230includes a received-current sensor231for detecting a received current supplied to the power converter240from the receiving coil220. For example, the received-current sensor231may measure a potential difference between opposite ends of the shunt resistor or measure a magnetic field due to a current.

The received-current sensor231may supply an electric signal (e.g., the potential difference between the opposite ends of the shunt resistor or output code of the hall sensor) corresponding to a measured current to the reception controller280. The reception controller280may identify the intensity of a current output from the receiving coil220based on an output signal of the received-current sensor231and calculate the amount of power received from the power station100through the receiving coil220.

The power converter240may receive alternating current power from the receiving coil220and convert the alternating current power into direct-current (DC) power under control of the reception controller280. The power converter240includes a rectifier241and a DC/DC converter242.

The rectifier241may include a diode bridge that rectifies alternating current power received through the receiving coil220. For example, the rectifier241may convert an alternating current voltage, which changes in direction and intensity, into a rectified voltage, which is constant in direction. The rectifier241may include a DC link capacitor to constantly stabilize the magnitude of a rectified voltage.

The DC/DC converter242may change a voltage of power rectified/stabilized by the rectifier241. The DC/DC converter242may convert, for example, a voltage of power output from the rectifier241to match either a rated voltage of the electric load250or a rated voltage of the second communicator260and/or the reception controller280.

In some cases, the power converter240may be omitted. For example, when the electric load250generates only heat, alternating current power of the receiving coil220may be supplied directly to the electric load250.

On the other hand, when the electric load250includes, for example, a motor, a light-emitting diode or the like, the alternating current power of the receiving coil220is not available for the electric load250. In this case, the power converter240is required.

The electric load250may be configured to convert electric energy into heat, light, and/or kinetic energy (rotational and/or translational energy). In addition, the electric load250may be configured to store electric energy. For example, the electric load250may include a light-emitting diode for heating an object or emitting light to the object, a motor for rotating an object, a battery for storing electric energy, or the like.

The electric load250may have various electrical properties according to the type thereof. For example, a heater may act as an electrical resistance and a motor may act as an inductor. A battery may act as a capacitor.

The second communicator260may communicate with the power station100. The second communicator260may include a reception antenna261provided separately from the receiving coil220and wirelessly transmit data to or receive data from the first communicator150of the power station100through the reception antenna261. For example, for communication efficiency, the reception antenna261may be formed at an inner or outer side of the receiving coil220to be concentrically positioned with the receiving coil220.

The second communicator260may wirelessly transmit data to or receive data from the first communicator150using a communication standard such as a wireless LAN or short-range wireless communication.

The auxiliary power source270may supply power to the reception controller280and the second communicator260when power cannot be supplied to the electric devices201and202from the power station100so that the electric devices201and202may be supplied with power from the power station100.

For example, the auxiliary power source270may include a battery. The auxiliary power source270may collect power by receiving a low-power radio signal, which is emitted through an antenna of the first communicator150, through an antenna of the second communicator260so that the power station100may search for the electric devices201and202. Alternatively, the auxiliary power source270may collect power by receiving a low-magnitude magnetic field, which is emitted through the transmitting coil120, through the receiving coil220so that the power station100may search for the electric devices201and202.

The auxiliary power source270may provide the reception controller280and/or the second communicator260with power stored in the battery or power collected through the antenna/receiving coil220.

The reception controller280and/or the second communicator260may operate using power provided from the auxiliary power source270when power cannot be supplied to the electric devices201and202from the power station100.

The reception controller280may control the power converter240to receive power wirelessly from the power station100. For effective power transmission, the reception controller280may provide the power station100with information including the amount of power received from the power station100and/or the intensity of a wireless communication signal received from the power station100.

The reception controller280may control the electric load250to provide a service in response to a user input while power is received stably from the power station100.

As such, the power station100may wirelessly supply power to the electric devices201and202. In addition, the power station100may identify whether the receiving coils220of the electric devices201and202are aligned with the transmitting coil120. For example, the transmission controller160may identify whether the electric devices201and202are located at a reference position for alignment of the transmitting coil120and the receiving coil220.

The components of the power station100and the functions thereof will be described in more detail below.

FIG.5illustrates a configuration of a wireless power station according to an embodiment.FIG.6illustrates examples of a first inverter and a first transmitting coil illustrated inFIG.5.

As shown inFIG.5, a power station100includes a control panel110, a plurality of transmitting coils121and122, a driver130, a transmission sensor140, a first communicator150, and a transmission controller160.

The control panel110may include a user inputter111for receiving a control command from a user, and a display112displaying an image relating to an operation of the power station100.

The user inputter111may include an input button for receiving a predetermined control command, a touch pad for receiving various control commands according to an image displayed on the display112, and the like. The touch pad may receive a touch input from a user and transmit coordinates of the received touch input to the transmission controller160. The transmission controller160may identify a control command from a user based on the coordinates of the touch input.

The input button may include a plurality of buttons for receiving a predetermined control command from a user and transmitting an electrical signal corresponding to the control command to the transmission controller160. For example, the input button may include an operation button for receiving a command to power on/off the power station100, a power-up button and a power-off button for receiving information about a magnitude of electromagnetic fields and/or magnetic fields output from coils120of the power station100, and the like.

The input button may be embodied as various types of buttons (or switches). For example, the input button may be embodied as a push button, a slide button, a toggle button, a touch button, a dial, or the like.

The display112may display an image relating to an operation of the power station100. For example, the display112may display an image indicating whether the coils120of the power station100are being operated, magnetic fields output from the coils120and/or the intensity of an electromagnetic field, and the like.

The display112may include various types of display means. The display112may include, for example, a light-emitting diode (LED), a liquid crystal display, or an organic light-emitting diode (OLED), or the like.

The user inputter111and the display112may be integrally formed. For example, a touch pad and a display may be integrally formed as a touch screen panel (TSP). The display displays an image for receiving a touch input from a user and the touch pad may receive the touch input. The transmission controller160may identify a control command from a user based on the coordinates of the touch input.

As such, the control panel110may receive a control command from a user and transmit an electrical signal corresponding to the control command from the user to the transmission controller160. In addition, the control panel110may receive information about an operation of the power station100from the transmission controller160and display an image indicating the operation of the power station100.

When the power station100is placed on an upper plate102, each of a plurality of transmitting coils121and122may generate a magnetic field and/or an electromagnetic field for providing power to the power station100.

The plurality of transmitting coils121and122may include a first transmitting coil121and a second transmitting coil122as described above, and the first transmitting coil121and the second transmitting coil122may be arranged in parallel at left and right sides of the upper plate102.

The driver130may be supplied with power from an external power source ES and supply a drive current to the plurality of transmitting coils121and122according to a driving control signal from the transmission controller160. Specifically, the driver130may apply an alternating current voltage to the plurality of transmitting coils121and122according to a control signal from the transmission controller160and output an alternating current (drive current).

The driver130includes a first inverter131aand a second inverter131b.

The first and second inverters131aand131bmay apply an alternating current voltage to the first and second transmitting coils121and122and supply an alternating current thereto. The first inverter131amay supply a drive current to the first transmitting coils121, and the second inverter131bmay supply a drive current to the second transmitting coil122.

As shown inFIG.6, the first inverter131amay be connected to the first transmitting coil121.

The first inverter131amay include a first inverter switch Q1and a second inverter switch Q2to supply a drive current to the first transmitting coil121or prevent the supply of the drive current to the first transmitting coil121, and a first resonant capacitor C1and a second resonant capacitor C2that resonate with the first transmitting coil121.

One end of the first inverter switch Q1may be connected to a positive terminal P, one end of the second inverter switch Q2may be connected to a negative terminal N, and another end of the first inverter switch Q1may be connected to another end of the second inverter switch Q2. In other words, the first inverter switch Q1and the second inverter switch Q2may be connected in series between the positive terminal P and the negative terminal N.

The first inverter switch Q1and the second inverter switch Q2may be turned on/off at a high speed of 10 kHz (kilohertz) to 100 kHz and may include a 3-terminal semiconductor device switch with a high response speed. For example, the first inverter switch Q1and the second inverter switch Q2may each include a bipolar junction transistor (BJT), a metal-oxide semiconductor field-effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), a thyristor, and the like.

One end of the first resonant capacitor C1may be connected to the positive terminal P, one end of the second resonant capacitor C2may be connected to the second negative terminal N, and another end of the first resonant capacitor C1may be connected to another end of the second resonant capacitor C2. In other words, the first resonant capacitor C1and the second resonant capacitor C2may be connected in series between the positive terminal P and the negative terminal N.

The first transmitting coil121may be provided between a first node N1connected to the first inverter switch Q1and the second inverter switch Q2and a second node N2connected to the first resonant capacitor C1and the second resonant capacitor C2. In other words, one end of the first transmitting coil121may be connected to the first node N1, and another end of the first transmitting coil121may be connected to the second node N2.

The first inverter switch Q1and the second inverter switch Q2may be turned on/off according to a control signal from the transmission controller160. As the first inverter switch Q1and the second inverter switch Q2are turned on/off, a current may flow through the first inverter switch Q1, the first transmitting coil121, and the second resonant capacitor C2or through the first resonant capacitor C1, the first transmitting coil121, and the second inverter switch Q2.

As such, the intensity and direction of the current flowing through the first transmitting coil121may be changed by turning on/off the first inverter switch Q1and the second inverter switch Q2included in the first inverter131a. In other words, an alternating current may be supplied to the first transmitting coil121from the first inverter231.

As the first and second inverter switches Q1and Q1are turned on/off, a resonance may occur between the first transmitting coil121and the first and second resonant capacitors C1and C2, and an alternating current may flow through the first transmitting coil121due to the resonance between the first transmitting coil121and the first and second resonant capacitors C1and C2.

The transmission sensor140includes a first current sensor141aand a second current sensor141b.

The first and second current sensors141aand141bmay measure the intensity and direction of a drive current supplied to the first transmitting coil121from the first inverter131aand the intensity and direction of a drive current supplied to the second transmitting coil122from the second inverter131b, respectively. For example, each of the first and second current sensors141aand141bmay measure a potential difference between opposite ends of a shunt resistor or measure a magnetic field generated from a current.

The first and second current sensors141aand141bmay supply an electrical signal (e.g., the potential difference between the opposite ends of the shunt resistor or output code of a hall sensor) corresponding to a measured current to the transmission controller160. The transmission controller160may identify the intensity of a drive current supplied to the transmitting coil120based on an output signal of the transmission current sensor141and calculate the amount of power wirelessly transmitted to the electric devices201and202through the transmitting coil120.

The first communicator150includes a wireless LAN module152and a short-range communication module153.

The wireless LAN module152may exchange data with an access point (AP) and wirelessly exchange data with the electric devices201and202through the AP. For example, the wireless LAN module152may connect to a local network such as an intranet and/or a wide network such as the Internet through the AP. In addition, the electric devices201and202may also connect to a local network and/or a wide network, and the wireless LAN module152may exchange data with the electric devices201and202through the local network and/or the wide network.

The wireless LAN module152may exchange data wirelessly with the AP using a Wi-Fi™ communication protocol. In addition, the electric devices201and202may also wirelessly exchange data with the AP.

The short-range communication module153may exchange data directly with electric devices201and202. For example, the short-range communication module153may transmit a radio signal directly to the electric devices201and202and receive a radio signal transmitted directly from the electric devices201and202.

The short-range communication module153may exchange data wirelessly with the electric devices201and202using, for example, the Wi-Fi Direct™ communication protocol, a Bluetooth™ communication protocol, or a near-field communication (NFC) communication protocol.

The wireless LAN module152and the short-range communication module153may each include a dedicated antenna provided separately from the first transmitting coil121or the second transmitting coil122.

For example, the short-range communication module153may include a first antenna151aand a second antenna151bdedicated thereto. As shown inFIG.5, the first and second antennas151aand151bmay be formed at an inner or outer side of the first and second transmitting coils121and122to be positioned concentrically with the first and second transmitting coils121and122, respectively.

The transmission controller160may control the driver130to wirelessly supply power to the electric devices201and202based on whether the electric devices201and202are placed on the upper plate102. For example, the transmission controller160may select at least one of a plurality of coils120based on detection of the electric devices201and202and control the driver130to supply a drive current to the at least one selected coil120.

The transmission controller160may identify whether there is an object on the upper plate102through the plurality of coils120. For example, the transmission controller160may control the driver130to supply a sensing current to the plurality of coils120and identify whether there is an object on the upper plate102based on the current of the plurality of coils120.

The transmission controller160may control the short-range communication module153to transmit a radio signal to an object based on identifying the placement of the object on the upper plate102. The transmission controller160may identify whether an object is the electric device201or202capable of wirelessly receiving power based on whether a radio signal is received from the object.

The transmission controller160may identify whether the transmitting coil120is aligned with the receiving coils220of the electric devices201and202during communication with the electric devices201and202based on the intensity of a communication signal. For example, the transmission controller160may identify whether the electric devices201and202are located at a reference position for alignment of the transmitting coil120and the receiving coil220.

The transmission controller160may warn a user based on the non-alignment of the transmitting coil120with the receiving coils220of the electric devices201and202. For example, the transmission controller160may warn a user based on the positioning of the electric devices201and202at a non-reference position.

The transmission controller160may control the driver130to supply a drive current to the transmitting coil120based on identifying the placement of the electric devices201and202on the upper plate102.

The transmission controller160may include a processor161and a memory162.

The memory162may store a control program and control data for controlling an operation of the power station100. In particular, the memory162may store a driving program and driving data for controlling the driver130. In addition, the memory162may temporarily store a result of processing by the processor161and the like.

The memory162may store a program and/or data according to a request from the processor161and provide the stored program and/or data to the processor161.

The memory162may include a volatile memory such as a static random access memory (SRAM) or a dynamic random access memory (DRAM) and a nonvolatile memory such as a read-only memory (ROM), an erasable programmable read-only memory (EPROM) or a flash memory.

The processor161may process data of the memory162according to the program provided from the memory162and generate a control signal for controlling the driver130, the control panel110, and the like according to a result of processing the data.

The processor161may include a logical operation circuit, an arithmetic operation circuit, a storage circuit, etc.

The memory162and the processor161may each be embodied as separate integrated circuits (ICs) or may be implemented together as an IC.

FIG.7illustrates an example of power transmission strength of a first transmitting coil according to an operating frequency of a first inverter included in a power station according to an embodiment.FIG.8illustrates an example of a drive current supplied to a first transmitting coil from a first inverter included in a power station according to an embodiment.FIG.9illustrates another example of a drive current supplied to a first transmitting coil from a first inverter included in a power station according to an embodiment.

A drive current (power) supplied to the first transmitting coil121may vary according to a turn-on/off frequency (switching frequency) of the first and second inverter switches Q1and Q2. Thus, the amount of power transmitted to the electric devices201and202through the first transmitting coil121may vary according to switching frequencies of the first and second inverter switches Q1and Q2.

For example, the amount of power supplied to the first transmitting coil121may be maximum when the switching frequencies of the first and second inverter switches Q1and Q2are the same as a resonance frequency f0between the first transmitting coil121and the first and second resonant capacitors C1and C2.

When the switching frequencies of the first and second inverter switches Q1and Q2are higher than the resonance frequency f0, the amount of power supplied to the first transmitting coil121may decrease as the switching frequency increases. As shown inFIG.9, the amount of power supplied to the first transmitting coil121when the first and second inverter switches Q1and Q2are switched at a first frequency f1higher than the resonance frequency f0is greater than the amount of power supplied to the first transmitting coil121when the first and second inverter switches Q1and Q2are switched at a second frequency f2higher than the first frequency f1.

When the switching frequencies of the first and second inverter switches Q1and Q2are higher than the resonance frequency f0, the intensity of a magnetic field generated by the first transmitting coil121may decrease as the switching frequency increases.

When the switching frequencies of the first and second inverter switches Q1and Q2are lower than the resonance frequency f0, the amount of power to be supplied to the first transmitting coil121may decrease as the switching frequency reduces. When the switching frequencies of the first and second inverter switches Q1and Q2are lower than the resonance frequency f0, the intensity of a magnetic field generated by the first transmitting coil121may decrease as the switching frequency reduces.

As described above, alternating current power is supplied to the first transmitting coil121due to switching operations of the first and second inverter switches Q1and Q2included in the first inverter231, and the first transmitting coil121may generate a magnetic field B. The intensity of the magnetic field B generated by the first transmitting coil121may vary according to the switching frequencies of the first and second inverter switches Q1and Q2. When the switching frequencies of the first and second inverter switches Q1and Q2are higher than the resonance frequency f0, the intensity of a magnetic field generated by the first transmitting coil121may decrease as the switching frequency increases.

A drive current supplied to the first transmitting coil121by the first inverter131amay be, for example, as shown inFIG.8or9.

As shown inFIG.8, the drive current may include a carrier C1of a frequency between, for example, 10 kHz to 100 kHz. The carrier C1may be generated due to a resonance between the first transmitting coil121and the first and second resonant capacitors C1and C2when the first inverter switch Q1is turned on/off.

In this case, an amplitude of the carrier C1(an envelope E1of the carrier C1) may change in the form of a sine wave. The envelope E1may be, for example, a sine wave of a 50 Hz or 60 Hz. A frequency of the envelope E1may be the same as, for example, a frequency of the external power source ES.

The envelope E1that is in the form of sine wave may periodically become “0.” When the envelope E1of the carrier C1is “0,” a drive current is not supplied to the transmitting coil120and no power is transmitted to the electric devices201and202through the transmitting coil120. In other words, there is an idle period Tslot in which the supply of power is stopped.

Specifically, the operation of the power station100may be divided into a transmission period Tpower in which power is supplied to the electric devices201and202and the idle period Tslot in which the supply of power to the electric devices201and202is stopped.

During the idle period Tslot, the power station100may exchange data with electric devices201and202through communication with the electric devices201and202. For example, the power station100may obtain information about operations of the electric devices201and202during the idle period Tslot.

As shown inFIG.9, the drive current may include a carrier C2of a frequency between, for example, 10 kHz to 100 kHz.

In this case, an amplitude of the carrier C2(an envelope E2of the carrier C2) may change in the form of a square wave. The envelope E2may be, for example, a sine wave of 50 Hz or 60 Hz.

The envelope E2that is in the form of square wave may periodically become “0.” In other words, there is the idle period Tslot in which the supply of power is stopped. The operation of the power station100may be divided into the transmission period Tpower and the idle period Tslot, and the power station100may obtain information about the operations of the electric devices201and202during the idle period Tslot.

An operation of the power station100will be described below.

FIG.10illustrates an example of identifying whether a power station is aligned with an electric device according to an embodiment.FIG.11illustrates an example in which a power station is not aligned with an electric device according to an embodiment.FIG.12illustrates an example in which a power station is aligned with an electric device according to an embodiment.

An example1000of identifying whether the power station100is aligned with the electric devices201and202will be described with reference toFIGS.10,11, and12below.

The power station100searches for and identifies objects to which power is to be transmitted wirelessly (1010).

The transmission controller160may periodically identify whether objects to which power is to be transmitted wirelessly are placed on the upper plate102.

For example, the transmission controller160may control the first and second inverters131aand131bto supply a sensing current, for sensing an object, to the first and second transmitting coils121and122. The first and second inverters131aand131bmay apply a low alternating current voltage, for sensing an object, to the first and second transmitting coils121and122under control of the transmission controller160.

The first and second current sensors141aand141bmay measure a current supplied to (a current flowing through) the first and second transmitting coils121and122using a low alternating current voltage for sensing an object and transmit an electrical signal corresponding to the measured current to the transmission controller160.

The transmission controller160may identify whether there are objects on the upper plate102based on output signals of the first and second current sensors141aand141b(currents flowing through the first and second transmitting coils121and122). In addition, the transmission controller160may identify whether objects are placed at a position corresponding to the first transmitting coil121or a position corresponding to the second transmitting coil122.

The power station100attempts to wirelessly communicate with the objects to which power is to be transmitted wirelessly (1020).

The transmission controller160may attempt to communicate with the objects based on identifying the placement of the objects on the upper plate102.

For example, the transmission controller160may control the first communicator150to wirelessly transmit a request signal requesting to transmit a response from the objects. The first communicator150may transmit the request signal through the transmission antenna151and wait for response signals from the objects.

The transmission controller160may identify, as the electric devices201and202, the objects to which power is to be transmitted wirelessly based on the response signals received from the objects within a predetermined time through the first communicator150. The transmission controller160may identify that an object is not an object to which power is to be transmitted wirelessly based on a response signal that is not received from the object within the predetermined time through the first communicator150.

For example, the electric devices201and202may transmit response signals including identification information thereof to the power station100in response to a request signal from the power station100. The transmission controller160may identify the electric devices201and202based on the response signals from the electric devices201and202.

The power station100obtains information about the intensity of a radio signal for communication with the objects to which power is to be transmitted (1030).

The transmission controller160may measure the intensities of radio signals received from the electric devices201and202. For example, the first communicator150may measure the intensity of a radio signal received through the transmission antenna151and provide the transmission controller160with information about the measured intensity of the radio signal.

The transmission controller160may obtain information about the intensity of a radio signal received by the electric devices201and202from the power station100. For example, the electric devices201and202may transmit a response signal including information about the intensity of a received signal to the power station100in response to a request signal from the power station100. The information about the intensity of the received signal may be in various formats. For example, the information about the intensity of the received signal may include a received-signal strength indicator.

The power station100identifies whether the objects to which power is to be transmitted is aligned therewith (1040).

The transmission controller160may identify whether the transmitting coil120of the power station100is aligned with the receiving coils220of the electric devices201and202based on the intensity of the radio signal. The transmission controller160may identify whether the electric devices201and202are located at a reference position for alignment of the transmitting coil120and the receiving coil220.

For example, as shown inFIG.11, when a receiving coil220of an electric device200is not aligned with the transmitting coil120of the power station100, the efficiency of power transmission to the receiving coil220from the transmitting coil120may decrease. Specifically, when the distance D between a central axis of the receiving coil220and a central axis of the transmitting coil120is greater than a reference distance, the efficiency of power transmission to the receiving coil220from the transmitting coil120may be less than a reference value.

The transmission controller160may identify whether the receiving coil220is aligned with the transmitting coil120based on the intensity of a radio signal used for communication with the electric device200. A central axis of the transmission antenna151of the short-range communication module153may substantially coincide with the central axis of the transmitting coil120. Accordingly, when the distance D between the central axis of the receiving coil220and the central axis of the transmitting coil120is greater than the reference distance, the central axis of the transmission antenna151and a central axis of the reception antenna261may be greater than the reference distance. Therefore, the intensity of a radio signal received by the power station100or the electric device200may be less than a reference intensity.

Therefore, the transmission controller160may identify that the transmitting coil120is not aligned with the receiving coil220when the intensity of the radio signal is less than the reference intensity.

For example, as shown inFIG.11, when the distance D between the central axis of the receiving coil220and the central axis of the transmitting coil120is less than the reference distance, the efficiency of power transmission to the receiving coil220from the transmitting coil120may be greater than the reference value. When the distance D between the central axis of the receiving coil220and the central axis of the transmitting coil120is less than the reference distance, the intensity of a radio signal received by the power station100or the electric device200may be greater than the reference intensity.

Therefore, the transmission controller160may identify that the transmitting coil120is aligned with the receiving coil220when the intensity of the radio signal is greater than or equal to the reference intensity.

When it is identified that the power station100is not aligned with the objects to which power is to be transmitted (No in1040), the power station100displays the non-alignment with the objects (1050).

The transmission controller160may identify whether the transmitting coil120is aligned with the receiving coil220based on reception strength of radio signals received from and/or received by the electric devices201and202.

When the transmitting coil120is not aligned with the receiving coil220, the efficiency of power transmission to the receiving coil220from the transmitting coil120may be lower than a reference value for permission of wireless power transmission.

The transmission controller160may control the display112to display a message indicating that the transmitting coil120is not aligned with the receiving coil220based on the non-alignment of the transmitting coil120with the receiving coil220. For example, the transmission controller160may control the display112to display a message requesting to reposition the electric devices201and202on the upper plate102.

The transmission controller160may control the wireless LAN module152to transmit a message indicating that the transmitting coil120is not aligned with the receiving coil220based on the non-alignment of the transmitting coil120with the receiving coil220. For example, the transmission controller160may control the wireless LAN module152to transmit a message requesting to reposition the electric devices201and202on the upper plate102.

During displaying of a message on the display112, the transmission controller160may communicate with the electric devices201and202, obtain information about the intensities of radio signals, and identify whether the power station100is aligned with the electric devices201and202.

When it is identified that the power station100is aligned with the objects to which power is to be transmitted (Yes in1040), the power station100wirelessly transmits power to the objects (1060).

The transmission controller160may control the driver130to wirelessly transmit power through the transmitting coil120based on the alignment of the transmitting coil120with the receiving coil220. For example, the transmission controller160may alternately turn on or off the first inverter switch Q1and the second inverter switch Q2of the first inverter131ato supply an alternating current to the first transmitting coil121.

As the first and second inverter switches Q1and Q2are turned on/off, an alternating current may be supplied to the first transmitting coil121, and the first transmitting coil121may provide an alternating current magnetic field. Due to the alternating current magnetic field, an alternating current may be induced to the receiving coil220, and power may be supplied to the electric devices201and202.

As described above, the power station100may identify whether the transmitting coil120is aligned with the receiving coil220during communication with the electric devices201and202based on the intensity of a radio signal and may request a user to reposition the electric devices201and202based on whether the transmitting coil120is aligned with the receiving coil220.

Thus, the power station100may allow the user to reposition the electric devices201and202such that the transmitting coil120is aligned with the receiving coil220. In addition, the power station100may improve the efficiency of power transmission to the electric devices201and202.

FIG.13illustrates an example of identifying whether a power station is aligned with an electric device according to an embodiment.

An example1100of identifying whether the power station100is aligned with the electric devices201and202will be described with reference toFIG.13below.

The power station100wirelessly transmits power to an object to which power is to be transmitted (1110).

As described above, the transmission controller160may control the driver130to wirelessly transmit power through the transmitting coil120based on the alignment of the transmitting coil120with the receiving coil220.

The power station100communicates with the object to which power is to be transmitted during an idle period of a power transmission operation (1120).

As described above with reference toFIGS.8and9, the power transmission operation may be divided into a transmission period Tpower in which power is supplied to the electric devices201and202and an idle period Tslot in which the supply of power to the electric devices201and202is stopped.

During the transmission period Tpower, the transmission controller160may control the driver130to wirelessly transmit power to the electric device201and202.

During the idle period Tslot, the transmission controller160may control the short-range communication module153to exchange data with the electric devices201and202. For example, the transmission controller160may receive operation information of the electric devices201and202or information about reception strength of communication signals from the electric devices201and202.

The power station100obtains information about the reception strength of a radio signal for communication with the object to which power is to be transmitted (1130).

During the idle period Tslot, the transmission controller160may measure the intensities of radio signals received from the electric devices201and202. During the idle period Tslot, the transmission controller160may also receive information about the intensity of a radio signal received from the power station100by the electric devices201and202.

The power station100identifies whether the object to which power is to be transmitted is aligned therewith (1140).

The transmission controller160may identify whether the transmitting coil120of the power station100is aligned with the receiving coils220of the electric devices201and202based on the intensity of the radio signal.

Operation1140may be substantially the same as operation1040illustrated inFIG.10.

When it is identified that the power station100is not aligned with the object to which power is to be transmitted (No in1140), the power station100stops the transmission of power to the object to which power is transmitted (1150).

The power station100may wirelessly transmit power to the electric devices201and202when the electric devices201and202are placed on the power station100based on the alignment of the transmitting coil120with the receiving coil220.

Thereafter, the electric devices201and202may be moved onto the upper plate102. For example, the electric devices201and202may be moved by a user or through an operation of the electric devices201and202.

When the electric devices201and202are moved during the alignment of the transmitting coil120with the receiving coil220, the transmitting coil120may not be aligned with the receiving coil220. In other words, the alignment of the transmitting coil120and the receiving coil220may be canceled due to the movement of the electric devices201and202.

As such, when the alignment of the transmitting coil120and the receiving coil220is canceled, the transmission controller160may control the driver130to stop the transmission of power to the electric devices201and202. For example, the transmission controller160may turn off both the first inverter switch Q1and the second inverter switch Q2.

Thereafter, the power station100displays non-alignment with the object to which power is to be transmitted (1160).

Operation1160may be the same as operation1050illustrated inFIG.10.

When it is identified that the power station100is aligned with the object to which power is to be transmitted (Yes in1140), the power station100continuously transmits power to the object to which power is to be transmitted (1170).

Operation1170may be the same as operation1060illustrated inFIG.10.

As described above, the power station100may communicate with the electric devices201and202during wireless transmission of power to the electric devices201and202and identify whether the transmitting coil120is aligned with the receiving coil220based on reception strength of a radio signal. In addition, the power station100may stop the transmission of power to the electric devices201and202and request a user to reposition the electric devices201and202based on whether the transmitting coil120is aligned with the receiving coil220.

Therefore, the power station100may identify non-alignment of the transmitting coil120and the receiving coil220due to the movement of the electric device201and202during an operation of the power station100. The power station100may allow the user to reposition the electric devices201and202such that the transmitting coil120is aligned with the receiving coil220. In addition, the power station100may improve the efficiency of power transmission to the electric devices201and202.

FIG.14illustrates an example of a transmission antenna of a short-range communication module included in a power station according to an embodiment.

FIG.5illustrates the transmission antenna151disposed on an inner or outer side of the transmitting coil120to be positioned concentrically with the transmitting coil120. However, the transmission antenna151is not limited to that shown inFIG.5.

The transmission antenna151may be disposed near the transmitting coil120. For example, the transmission antenna151may be disposed on a circumference of a circle surrounding the transmitting coil120as shown inFIG.14.

The transmission antenna151may include a first auxiliary antenna151c, a second auxiliary antenna151d, a third auxiliary antenna151e, and a fourth auxiliary antenna151f, and the first, second, third and fourth auxiliary antennas151c,151d,151e, and151fmay be disposed along the circumference of the circle surrounding the transmitting coil120.

The first, second, third and fourth auxiliary antennas151c,151d,151eand151fmay be arranged at a predetermined angle interval to maximize a distance therebetween. For example, the first, second, third and fourth auxiliary antennas151c,151d,151eand151fmay be arranged along the circumference of the circle surrounding the transmitting coil120such that an angle interval therebetween is approximately 90 degrees.

By arranging the transmission antenna151along the circumference of the circle surrounding the transmitting coil120, the power station100may identify a position of the receiving coil220relative to the transmitting coil120through communication with the electric devices201and202.

The power station100may measure reception strength of radio signals received through the auxiliary antennas151c,151d,151e, and151f. The power station100may measure first reception strength of a radio signal during communication with the electric devices201and202through the first auxiliary antenna151c, measure second reception strength of a radio signal during communication with the electric devices201and202through the second auxiliary antenna151d, measure third reception strength of a radio signal during communication with the electric devices201and202through the third auxiliary antenna151e, and measure fourth reception strength of a radio signal during communication with the electric devices201and202through the fourth auxiliary antenna151f.

The power station100may identify the distances between the auxiliary antennas151c,151d,151e, and151fand the reception antenna261based on the measured reception strengths of the radio signals. The power station100may calculate a first distance between the first auxiliary antenna151cand the reception antenna261based on the first reception strength, calculate a second distance between the second auxiliary antenna151dand the reception antenna261based on the second reception strength, calculate a third distance between the third auxiliary antenna151eand the reception antenna261based on the third reception strength, and calculate a fourth distance between the fourth auxiliary antenna151fand the reception antenna261based on the fourth reception strength.

The power station100may identify a position of the receiving coil220relative to the transmitting coil120based on the distances between the auxiliary antennas151c,151d,151e, and151fand the reception antenna261. The power station100may identify the position of the receiving coil220relative to the transmitting coil120based on the first distance, the second distance, the third distance, and the fourth distance. The power station100may identify whether the transmitting coil120is aligned with the receiving coil220based on the position of the receiving coil220relative to the transmitting coil120.

Alternatively, the power station100may identify a direction in which the electric devices201and202are to be moved so as to align the transmitting coil120with the receiving coil220. The power station100may display an image for guiding the electric devices201and202to be moved in the identified direction on the display112. For example, the power station100may identify the direction in which the electric devices201and202are to be moved based on a largest value among the first distance, the second distance, the third distance, and the fourth distance. When the fourth distance between the fourth auxiliary antenna151fand the reception antenna261is a largest value, the power station100may display an image for guiding the electric device201and202to be moved toward the fourth auxiliary antenna151fon the display112.

As described above, by arranging the transmission antenna151along the circumference of the circle surrounding the transmitting coil120, the power station100may identify the position of the receiving coil220relative to the transmitting coil120and identify the direction in which the electric devices201and202are to be moved so as to align the transmitting coil120with the receiving coil220.

FIG.15illustrates an example of identifying whether a power station is aligned with an electric device according to an embodiment.FIG.16illustrates an example in which a power station is not aligned with an electric device according to an embodiment.

An example1200of identifying whether the power station100is aligned with the electric devices201and202will be described with reference toFIGS.15and16below.

The power station100searches for and identifies an object to which power is to be transmitted wirelessly (1210) and attempts to wirelessly communicate with the object (1220).

Operations1210and1220may be the same as operations1010and1020ofFIG.10, respectively.

The power station100obtains information about reception strength of radio signals received through the auxiliary antennas151c,151d,151e, and151f.

The transmission controller160may measure intensities of radio signals received through the auxiliary antennas151c,151d,151e, and151f. For example, the first communicator150may measure the intensities of radio signals received through the first auxiliary antenna151c, the second auxiliary antenna151d, the third auxiliary antenna151eand the fourth auxiliary antenna151fand provide information about the measured intensities of the radio signals to the transmission controller160.

The transmission controller160may obtain information about the intensities of radio signals received from the auxiliary antennas151c,151d,151e, and151fof the power station100by the electric devices201and202. For example, the transmission controller160may obtain information about the intensities of radio signals received from the first auxiliary antenna151c, the second auxiliary antenna151d, the third auxiliary antenna151e, and the fourth auxiliary antenna151fby the electric devices201and202.

The power station100identifies whether the object to which power is to be transmitted is aligned therewith (1240).

The transmission controller160may identify the distances between the auxiliary antennas151c,151d,151e, and151fand the reception antenna261based on the intensities of the radio signals. The transmission controller160may identify a position of the receiving coil220relative to the transmitting coil120, based on the distances between the auxiliary antennas151c,151d,151e, and151fand the reception antenna261.

The transmission controller160may identify whether the transmitting coil120is aligned with the receiving coil220based on the position of the receiving coil220relative to the transmitting coil120. For example, when the difference between a maximum value and a minimum value among the distances between the auxiliary antenna151c,151d,151e, and151fand the reception antenna261is less than a reference value, the transmission controller160may identify that the transmitting coil120is aligned with the receiving coil220. On the other hand, when the difference between the maximum value and the minimum value among the distances between the auxiliary antenna151c,151d,151e, and151fand the reception antenna261is greater than the reference value, the transmission controller160may identify that the transmitting coil120is not aligned with the receiving coil220.

When it is identified that the power station100is not aligned with the object to which power is to be transmitted (No in1240), the power station100displays the non-alignment with the object to which power is to be transmitted (1250).

Operation1250may be the same as operation1050illustrated inFIG.10.

The power station100displays a direction in which the electric devices201and202are to be moved so as to align with the object to which power is to be transmitted (1260).

The transmission controller160may control the display112to display the direction in which the electric devices201and202are to be moved so as to align the transmitting coil120with the receiving coil220based on the non-alignment of the transmitting coil120with the receiving coil220.

The transmission controller160may identify the direction in which the electric devices201and202are to be moved based on the larges value among the distances between the auxiliary antennas151c,151d,151e, and151fand the reception antenna261. Specifically, the transmission controller160may control the display112to display an image for guiding the electric devices201and202to be moved toward an antenna spaced a largest distance from the reception antenna261.

For example, as shown inFIG.16, when the distance between the second auxiliary antenna151dand the reception antenna261is largest, the transmission controller160may control the display112to display an image I1for guiding the electric devices201and202to be moved toward the second auxiliary antenna151d.

A user may move the electric devices201and202according to an image displayed on the display112.

When it is identified that the power station100is aligned with the object to which power is to be transmitted (Yes in1240), the power station100wirelessly transmits power to the object (1270).

Operation1270may be the same as operation1060illustrated inFIG.10.

As described above, the power station100may display a direction in which the electric devices201and202are to be moved so as to align the transmitting coil120with the receiving coil220during communication with the electric devices201and202based on reception strength of a radio signal.

Accordingly, the power station100may allow a user to reposition the electric devices201and202such that the transmitting coil120is aligned with the receiving coil220. In addition, the power station100may improve the efficiency of power transmission to the electric devices201and202.

FIG.17illustrates an example of identifying whether a power station is aligned with an electric device according to an embodiment.

An example1300of identifying whether the power station100is aligned with the electric devices201and202will be described with reference toFIG.17below.

The power station100searches for and identifies an object to which power is to be transmitted wirelessly (1310) and attempts to wirelessly communicate with the object (1320).

Operations1310and1320may be the same as operations1010and1020ofFIG.10, respectively.

The power station100wirelessly transmits power to the object to which power is to be transmitted (1330).

Operation1330may be the same as operation1060illustrated inFIG.10.

The power station100communicates with the object to which power is to be transmitted during an idle period of a power transmission operation (1340).

The power transmission operation may be divided into a transmission period Tpower in which power is supplied to the electric devices201and202and an idle period Tslot in which the supply of power to the electric devices201and202is stopped.

During the idle period Tslot, the transmission controller160may control the short-range communication module153to exchange data with the electric devices201and202. For example, the transmission controller160may receive operation information of the electric devices201and202or information about the amount of power received wirelessly by the electric devices201and202.

The power station100obtains the information about the amount of power received wirelessly by the object to which power is to be transmitted (1350).

As described above, the electric devices201and202may calculate the amount of power received wirelessly based on an output of the received-current sensor231. The received-current sensor231may measure a current supplied from the receiving coil220to the power converter240, and the reception controllers280of the electric devices201and202may identify the intensity of a current output from the receiving coil220based on an output signal of the received-current sensor231and calculate the amount of power supplied from the power station100through the receiving coil220.

The electric devices201and202may transmit information about the amount of power, which is supplied from the power station100, to the power station100through wireless communication during the idle period Tslot.

The power station100may obtain the amount of power received by the electric devices201and202from the electric devices201and202.

The power station100identifies whether the object to which power is to be transmitted is aligned therewith (1360).

The transmission controller160may calculate a ratio of the amount of power received by the electric devices201and202through the receiving coil220to the amount of power transmitted from the power station100through the transmitting coil120(hereinafter referred to as a “power transmission rate”) and identify whether the transmitting coil120is aligned with the receiving coil220based on the power transmission rate.

The power station100may calculate the amount of power transmitted to the electric devices201and202based on an output of the transmission current sensor141. The transmission current sensor141may measure a drive current supplied from the inverter131to the transmitting coil120, and the transmission controller160may identify the intensity of a current supplied to the transmitting coil120based on an output signal of the transmission current sensor141, and calculate the amount of power transmitted to the electric devices201and202through the transmitting coil120.

The transmission controller160may calculate a “power transmission rate” based on a ratio of the amount of power received from the electric devices201and202to the amount of the transmitted power. For example, the transmission controller160may obtain a “power transmission rate” by dividing the amount of the received power by the amount of the transmitted power.

When the transmitting coil120is aligned with the receiving coil220, a linkage magnetic field passing through the receiving coil220may increase among magnetic fields generated by the transmitting coil120. Accordingly, the power transmission rate may increase. Therefore, the transmission controller160may identify that the transmitting coil120is aligned with the receiving coil220when the power transmission rate is greater than a reference transmission rate.

On the other hand, when the transmitting coil120is not aligned with the receiving coil220, a leakage magnetic field passing through the receiving coil220may increase among magnetic fields generated by the transmitting coil120. Accordingly, the power transmission rate may reduce. Therefore, the transmission controller160may identify that the transmitting coil120is not aligned with the receiving coil220when the power transmission rate is less the reference transmission rate.

When it is identified that the power station100is not aligned with the object to which power is to be transmitted (No in1360), the power station100stops the transmission of power to the object (1370) and displays the non-alignment with the object (1380).

Operations1370and1380may be the same as operations1150and1160ofFIG.13, respectively.

When it is identified that the power station100is aligned with the object to which power is to be transmitted (Yes in1360), the power station100continuously transmits power to the object (1390).

Operation1390may be the same as operation1170illustrated inFIG.13.

As described above, the power station100may calculate a transmission rate of power transmitted to the electric devices201and202during wireless transmission of power to the electric devices201and202and identify whether the transmitting coil120is aligned with the receiving coil220based on the transmission rate. In addition, the power station100may stop the transmission of power to the electric devices201and202and request a user to reposition the electric devices201and202based on whether the transmitting coil120is aligned with the receiving coil220.

Therefore, the power station100may identify non-alignment of the transmitting coil120and the receiving coil220due to the movement of the electric device201and202during an operation of the power station100. The power station100may allow the user to reposition the electric devices201and202such that the transmitting coil120is aligned with the receiving coil220. In addition, the power station100may improve the efficiency of power transmission to the electric devices201and202.

FIG.18illustrates an example of an auxiliary coil of a leakage sensor included in a power station according to an embodiment.

Although it has been described above that the power station100identifies whether the electric devices201and202are aligned therewith based on reception strength of a communication signal and/or a power transmission rate, a method of identifying whether the electric devices201and202are aligned with the power station100is not limited thereto.

For example, the power station100may identify whether the electric devices201and202are aligned therewith by detecting a leakage magnetic field.

As shown inFIG.18, auxiliary coils171a,171b,171c, and171dmay be disposed near the transmitting coil120to detect a leakage magnetic field. For example, the auxiliary coils171a,171b,171c, and171dmay be disposed on the circumference of a circle surrounding the transmitting coil120.

The auxiliary coils171a,171b,171c,171dinclude a first auxiliary coil171a, a second auxiliary coil171b, a third auxiliary coil171c, and a fourth auxiliary coil171d, and the first, second, third, and fourth auxiliary coils171a,171b,171c, and171dmay be disposed along the circumference of the circle surrounding the transmitting coil120.

The first, second, third, and fourth auxiliary antennas171a,171b,171c, and171dmay be arranged at a predetermined angle interval to maximize a distance therebetween. For example, the first, second, third, and fourth auxiliary antennas171a,171b,171c, and171dmay be arranged along the circumference of the circle surrounding the transmitting coil120such that an angle interval therebetween is approximately 90 degrees.

The auxiliary coils171a,171b,171c, and171darranged along the circumference of the circle surrounding the transmitting coil120may detect a magnetic field that is not transmitted from the transmitting coil120to the receiving coil220and is leaking.

The power station100may measure the intensity of a leakage magnetic field through the plurality of auxiliary coils171a,171b,171c, and171d. The plurality of auxiliary coils171a,171b,171c, and171dmay be connected to the leakage sensor170, and the leakage sensor170may measure the intensity of current induced by a leakage magnetic field detected by the plurality of auxiliary coils171a,171b,171c, and171dand provide an electrical signal corresponding to the magnitude of the leakage magnetic field to the transmission controller160.

The transmission controller160may identify the magnitude of the leakage magnetic field based on an output signal of the leakage sensor170, and identify whether the transmitting coil120is aligned with the receiving coil220based on the magnitude of the leakage magnetic field. When the magnitude of the leakage magnetic field is greater than a reference magnitude, the transmission controller160may identify that the transmitting coil120is not aligned with the receiving coil220. When the magnitude of the leakage magnetic field is less than the reference magnitude, the transmission controller160may identify that the transmitting coil120is aligned with the receiving coil220.

As described above, by arranging the auxiliary coils171(171a,171b,171c, and171d) along the circumference of the circle surrounding the transmitting coil120, the power station100may identify whether the transmitting coil120is aligned with the receiving coil220.

FIG.19illustrates an example of identifying whether a power station is aligned with an electric device according to an embodiment.

An example1400of identifying whether the power station100is aligned with the electric devices201and202will be described with reference toFIG.19below.

The power station100searches for and identifies an object to which power is to be transmitted wirelessly (1410) and attempts to wirelessly communicate with the object (1420).

Operations1410and1420may be the same as operations1010and1020ofFIG.10, respectively.

The power station100wirelessly transmits power to the object to which power is to be transmitted (1430).

Operation1430may be the same as operation1060illustrated inFIG.10.

The power station100obtains information about the magnitude of a leakage magnetic field (1440).

The transmission controller160may obtain information about the magnitude of the leakage magnetic field through the auxiliary coils171a,171b,171c,171dand the leakage sensor170.

The plurality of auxiliary coils171a,171b,171c, and171dmay detect a leakage magnetic field and supply a current induced by the leakage magnetic field to the leakage sensor170. The leakage sensor170may measure the intensity of a current induced by the leakage magnetic field and provide an electrical signal corresponding to the magnitude of the leakage magnetic field to the transmission controller160.

The transmission controller160can identify the magnitude of the leakage magnetic field based on an output signal of the leakage sensor170.

The power station100identifies whether the object to which power is to be transmitted is aligned therewith (1450).

The transmission controller160may identify whether the transmitting coil120is aligned with the receiving coil220based on the magnitude of the leakage magnetic field. When the magnitude of the leakage magnetic field is greater than a reference magnitude, the transmission controller160may identify that the transmitting coil120is not aligned with the receiving coil220. When the magnitude of the leakage magnetic field is less than the reference magnitude, the transmission controller160may identify that the transmitting coil120is aligned with the receiving coil220.

When it is identified that the power station100is not aligned with the object to which power is to be transmitted (No in1450), the power station100stops the transmission of power to the object (1460) and displays the non-alignment with the object (1470).

Operations1460and1470may be the same as operations1150and1160ofFIG.13, respectively.

When it is identified that the power station100is aligned with the object to which power is to be transmitted (Yes in1360), the power station100continuously transmits power to the object (1480).

Operation1480may be the same as operation1170illustrated inFIG.13.

As described above, the power station100may detect a leakage magnetic field during wireless transmission of power to the electric devices201and202and identify whether the transmitting coil120is aligned with the receiving coil220based on the magnitude of the leakage magnetic field. In addition, the power station100may stop the transmission of power to the electric devices201and202and request a user to reposition the electric devices201and202based on whether the transmitting coil120is aligned with the receiving coil220.

Therefore, the power station100may identify non-alignment of the transmitting coil120and the receiving coil220due to the movement of the electric device201and202during an operation of the power station100. The power station100may allow the user to reposition the electric devices201and202such that the transmitting coil120is aligned with the receiving coil220. In addition, the power station100may improve the efficiency of power transmission to the electric devices201and202.

FIG.20illustrates an example in which a power station identifies whether coils are aligned with each other, together with electric devices, according to an embodiment.

An example1500in which the power station100identifies whether the coils120and220are aligned with each other together with the electric devices201and202will be described with reference toFIG.20below.

The power station100transmits a response request signal to the electric devices201and202through the first communicator150(1510).

The electric devices201and202transmit a response signal (a reception strength signal) indicating the reception strength of the response request signal from the power station100to the power station100through the second communicator260, in response to the response request signal from the power station100(1515).

The power station100identifies whether the coils120and220are aligned with each other based on the reception strength signal from the electric devices201and202and displays whether the coils120and122are aligned with each other (1520).

The electric devices201and202identify whether the coils120and220are aligned with each other based on the reception strength of the response request signal and display whether the coils120and220are aligned with each other (1525).

The power station100transmits a minimum amount of power (e.g., 100 mW to 500 mW) through the transmitting coil120(1530).

The electric devices201and202transmit a requested-power signal indicating a requested amount of power for providing a user with a service to the power station100through the second communicator260(1535). The electric devices201and202may activate components to be operated using a minimum amount of power. For example, the electric devices201and202may activate a user interface and receive a control command from a user.

The power station100transmits the required amount of power to the electric devices201and202through the transmitting coil120in response to the requested-power signal from the electric devices201and202(1540).

The electric devices201and202transmit a response signal (a received-power amount signal) indicating the amount of received power to the power station100through the second communicator260(1545). The electric devices201and202may calculate the amount of power received during wireless receiving of power from the power station100and transmit the calculated amount of the received power to the power station100through the second communicator260.

The power station100identifies whether the coils120and220are aligned with each other based on the received-power amount signal from the electric devices201and202and displays whether the coils120and122are aligned with each other (1550).

The electric devices201and202identify whether the coils120and220are aligned with each other based on the calculated amount of the received power and display whether the coils120and220are aligned with each other (1555).

The power station100transmits an idle period start signal to the electric devices201and202through the first communicator150during an idle period Tslot of an operation thereof (1560).

The electric devices201and202transmit a reception strength/requested-power signal, which indicates reception strength of the idle period start signal from the power station100and the amount of power requested to provide a service to a user, to the power station100through second communicator260in response to the idle period start signal from the power station100(1565).

The power station100identifies whether the coils120and220are aligned with each other based on the reception strength/requested-power signal from the electric devices201and202and displays whether the coils120and122are aligned with each other (1570).

The electric devices201and202identify whether the coils120and220are aligned with each other based on the reception strength of the idle period start signal, and display whether the coils120and220are aligned with each other (1575).

The power station100transmits the required amount of power to the electric devices201and202through the transmitting coil120in response to the reception strength/requested-power signal from the electric devices201and202(1580).

As described above, the power station100may identify whether the receiving coil220is aligned with the transmitting coil120based on reception strength of a communication signal received by the electric devices201and202and/or the amount of power received wirelessly by the electric devices201and202.

Accordingly, the power station100may allow a user to reposition the electric devices201and202such that the transmitting coil120is aligned with the receiving coil220. In addition, the power station100may improve the efficiency of power transmission to the electric devices201and202.

FIG.21illustrates an example of controlling an operation of an electric device by a power station according to an embodiment.FIG.22illustrates an example of displaying a user interface for an electric device by a power station according to an embodiment.

An example1600in which the power station100controls the electric devices201and202in response to a response from a user will be described with reference toFIGS.21and22below.

The power station100searches for and identifies an object to which power is to be transmitted wirelessly (1610) and attempts to wirelessly communicate with the object (1620).

Operations1210and1220may be the same as operations1010and1020ofFIG.10, respectively.

The power station100displays user interfaces UI1and UI2for a power transmission object (1630).

The transmission controller160may identify the electric devices201and202through communication with the electric devices201and202. Specifically, the transmission controller160may identify the types, model names, and maximum power consumption rates, etc. of the electric devices201and202.

The user interfaces UI1and UI2according to the types, model names, etc. of the electric devices201and202and the like may be stored in advance in the memory162of the transmission controller160. For example, as shown inFIG.22, a first user interface UI1for manipulating an electric kettle201and a second user interface UI2for manipulating a toaster202may be stored in the transmission controller160.

The first user interface UI1may include a display displaying a target temperature of water contained in the electric kettle201, a button to raise the target temperature, a button for lowering the target temperature, and the like. The second user interface UI2may include a display displaying a target time for operating the toaster202, a button to increase the target time, a button for reducing the target time, and the like.

The transmission controller160may control the display112to display the user interfaces UI1and UI2corresponding to the identified electric devices201and202. In this case, the display112may include a touch screen panel.

The power station100obtains a user input for the power transmission object (1640).

The transmission controller160may obtain a user input with respect to the electric devices201and202through the user interfaces UI1and UI2displayed on the touch screen panel. For example, the transmission controller160may obtain a target temperature of the electric kettle201through the first user interface UI1or obtain a target time of the toaster202through the second user interface UI2.

The power station100transmits the obtained user input to the power transmission object (1650).

The transmission controller160may control the first communicator150to transmit the user input obtained through the user interfaces UI1and UI2to the electric devices201and202. For example, the transmission controller160may control the short-range communication module153to transmit information about the target temperature obtained through the first user interface UI1to the electric kettle201and to transmit information about the target time obtained through the second user interface UI2to the toaster202.

The power station100transmits power corresponding to the obtained user input to the power transmission object (1660).

The transmission controller160may control the driver130to transmit power corresponding to the user input obtained through the user interfaces UI1and UI2.

For example, the transmission controller160may stop the transmission of power to the electric kettle201in response to a message indicating that a temperature of water contained in the electric kettle201reaches the target temperature during an idle period Tslot of power transmission. The transmission controller160may stop the transmission of power to the toaster202in response to the reaching of a time, during which the power is transmitted to the toaster202, of the target time.

As another example, the transmission controller160may control the driver130to transmit power according to the intensity of an output of an electric device according to a user input. For example, the transmission controller160may control the driver130to adjust the amount of power to be transmitted to an electric fan according to an output of the electric fan in response to a user input for adjusting the output of the electric fan (e.g., high, middle or low power), received through a user interface.

As described above, the power station100may display a user interface for the electric devices201and202, obtain a user input with respect to a power transmission objects through the user interface, and transmit the user input to electric devices201and202. In other words, a user may control the electric devices201and202through the power station100.

Accordingly, the user may control both the electric devices201and202through the power station100. Because the user may control the electric devices201and202through the power station100, a control panel and the like of each of the electric devices201and202may be omitted.

A power station includes a plate, a coil below the plate, an inverter configured to supply an alternating current to the coil, a communication module including an antenna and configured to transmit and receive radio signals through the antenna, a display, and a controller configured to control the communication module to communicate with an external device placed on the plate and control the inverter to wirelessly transmit power to the external device through the coil. The controller may control the display to display information indicating whether the external device is aligned with the coil based on a radio signal received from the external device through the antenna.

The controller may identify whether the external device is aligned with the coil based on the radio signal received from the external device through the antenna, control the display to indicate non-alignment with the external device based on identifying that the external device is not aligned with the coil, and control the inverter to wirelessly supply power to the external device through the coil based on identifying that the external device is aligned with the coil.

As described above, the power station may identify whether the external device is aligned with the coil before an operation and guide a user to move the external device when the external device is not aligned with the coil. Accordingly, the efficiency of power transmission of the external device from the power station can be improved.

The controller may control the inverter to wirelessly supply power to the external device through the coil during a transmission period and identify whether the external device is aligned with the coil during an idle period based on a radio signal received from the external device through the antenna.

As described above, the power station may identify whether the external device is aligned with the coil during an operation and guide a user to move the external device when the external device is not aligned with the coil. Accordingly, the power station is capable of transmitting power to the external device with improved efficiency even when the external device is moving during the operation of the power station.

The controller may identify whether the external device is aligned with the coil based on the reception strength of the external device, which is included in a radio signal received from the external device or based on the reception strength of the radio signal received from the external device.

As described above, the power station may identify whether the external device is aligned with the coil based on the reception strength of a signal during communication with the external device. Accordingly, the power station may guide the external device to be aligned with the coil before an operation.

The controller may control the inverter to supply an alternating current with an envelope having a sine wave form to the coil and identify whether the external device is aligned with the coil based on a radio signal received from the external device through the antenna for a time interval during that the envelope having the sine wave form is approximately “0.”

Therefore, during an operation, the power station may communicate with the external device without causing a sharp fluctuation of power transmission and identify whether the external device is aligned with the coil.

The antenna has a circular shape provided at an outer side of the coil to surround the coil, and the center of the antenna may roughly coincide with the center of the coil.

Accordingly, the efficiency of power transmission between the power station and the external device can be improved.

The antenna may include a plurality of antennas arranged at an outer side of the coil and along the circumference of a virtual circle surrounding the coil, the plurality of antennas may be spaced substantially the same distance from each other, and the controller may identify whether the external device is aligned with the coil based on the reception strength of a radio signal received from the external device.

Therefore, the power station may guide a user to a direction in which the external device is to be moved so as to be aligned with the coil.

The embodiments set forth herein have been described above with reference to the accompanying drawings. It will be understood by those of ordinary skill in the technical field to which the embodiments set forth herein pertain that the present disclosure may be implemented in different forms than those of these embodiments without departing from the technical idea or essential features of the embodiments. The embodiments set forth herein are only examples and should not be interpreted in a restrictive manner.