POWER CONVERTING SYSTEM

A power converting system includes a power converting device, a protection device, and a charging device. The power converting device is coupled to a first and a second power source. The protection device is coupled to the power converting device, a load, and a grid, and switches electrical connections among the power converting device, the load, and the grid. The charging device is coupled to the power converting device and a third power source. The power converting device charges the third power source through the charging device, or receives electricity through the charging device. Select at least one power source of the first power source, the second power source, the third power source and the grid to provide electricity to the load according to multiple preset modes.

RELATED APPLICATIONS

This application claims priority to China Application Serial Number 202111375867.1 filed Nov. 19, 2021 and China Application Serial Number 202211369741.8 filed Nov. 3, 2022, which is herein incorporated by reference.

BACKGROUND

Field of Invention

The present disclosure relates to a converting device. More particularly, the present disclosure relates to a power converting system.

Description of Related Art

Solar battery charger system nowadays is usually constructed by multiple independent sub-systems. Photovoltaic (PV) energy storage system usually includes PV inverter and battery inverter to achieve energy conversion between new energy generation and energy storage through AC couple. Or Photovoltaic (PV) energy storage system achieves energy conversion between new energy generation and energy storage through DC couple. Electric vehicle (EV) charger is also connected to AC grid directly.

The Photovoltaic (PV) energy storage system and the electric vehicle charger are all independent devices. Since communication ports of each of the independent devices do not have a uniform standards and a uniform communication protocol, it is hard to communicate among the devices, such that it is not easy to achieve an electricity management among the whole system. In addition, each independent system needs independent grid-connected capacity, so the capacity of the AC ports will be not enough; and the installation cost and the maintenance cost are high.

SUMMARY

One aspect of the present disclosure is to provide a power converting system. The power converting system includes a power converting device, a protection device, and a charging device. The power converting device is coupled to a first power source and a second power source. The protection device is coupled to the power converting device, a load, and a grid, and configured to switch electrical connections among the power converting device, the load, and the grid. The charging device is coupled to the power converting device and a third power source. The power converting device charges the third power source through the charging device, or receives electricity of the third power source through the charging device. Select at least one power source of the first power source, the second power source, the third power source and the grid to provide electricity to the load according to multiple preset modes.

According to the usual mode of operation, various features and elements in the figures have not been drawn to scale, which are drawn to the best way to present specific features and elements related to the present disclosure. In addition, among the different figures, the same or similar element symbols refer to similar elements/components.

DESCRIPTION OF THE EMBODIMENTS

To make the contents of the present disclosure more thorough and complete, the following illustrative description is given with regard to the implementation aspects and embodiments of the present disclosure, which is not intended to limit the scope of the present disclosure. The features of the embodiments and the steps of the method and their sequences that constitute and implement the embodiments are described. However, other embodiments may be used to achieve the same or equivalent functions and step sequences.

Unless otherwise defined herein, scientific and technical terminologies employed in the present disclosure shall have the meanings that are commonly understood and used by one of ordinary skill in the art. Unless otherwise required by context, it will be understood that singular terms shall include plural forms of the same and plural terms shall include the singular. Specifically, as used herein and in the claims, the singular forms “a” and “an” include the plural reference unless the context clearly indicates otherwise.

FIG.1depicts a schematic diagram of a power converting system100according to one embodiment of the present disclosure. As shown in the figure, the power converting system100includes a power converting device110, a protection device120, and a charging device130. The power converting device110is electrically connected to the protection device120and the charging device130.

The power converting device110includes multiple input/output ports. Two input/output ports of the power converting device110are electrically connected to a first power source200and a second power source300. Besides, another input/output port of the power converting device110is electrically connected to the protection device120, and the power converting device110is electrically connected to a grid400and a load500through the protection device120. In addition, still another input/output port of the power converting device110is electrically connected to the charging device130, and the power converting device110is electrically connected to a movable energy storage device600through the charging device130. In some embodiments, the input/output port can include plural input/output terminals.

For example, the first power source200can be a photovoltaics panel. Therefore, the first power source200is configured to convert solar energy into electrical energy, and provide the electrical energy to the power converting device110. The second power source300can be energy storage battery. Therefore, the second power source300is configured to store electrical energy provided by the power converting device110, and provide electrical energy to the power converting device110through the second power source300if necessary. In some operation modes, the second power source may be a power load for receiving and storing electricity.

As shown inFIG.2, the protection device120includes a switch121, a transformer123, and a safe guard125. The switch121can be a contactor or a relay. Therefore, the switch121can be configured to control a switch state among the power converting device110, the grid400, and the load500. The transformer123can be an isolation transformer or an auto transformer, so as to perform a voltage-typed conversion. The safe guard125can be an overcurrent protection device or an electrical leakage protection device.

As shown inFIG.1, the charging device130can be a charging gun, and the movable energy storage device600can be an electric vehicle. Therefore, the movable energy storage device600can be charged or discharged through the charging device130. Specifically, the movable energy storage device600includes a second converter610and a third power source620. The third power source620can be an energy storage battery. The charging device130provides electricity to the second converter610, and the second converter610converts electricity and stores it in the third power source620. In some operation modes, the third power source may be a power load for receiving and storing electricity.

In one embodiment, the power converting device110includes a first converter111, a controller113, a sensor115, and a protector117. The first converter111is electrically connected to the controller113, the sensor115, and the protector117. The controller113is electrically connected to the sensor115and the protector117.

For example, the first converter111includes multiple input/output ports. The first converter111can be configured to perform a DC/DC conversion, a DC/AC conversion, or an AC/DC conversion. The controller113is configured to control the whole system. For instance, the controller113can communication with the charging device130for controlling the movable energy storage device600to charge or discharge, or perform a protection function. The sensor115can be a current sampler, a voltage sampler, or a combination of the current sampler and the voltage sampler. The sensor115can detect the current, the voltage, and the power signal of the movable energy storage device600, and provide the signals detected to the controller113for calculating the power of the movable energy storage device600. Besides, the sensor115can be also configured to detect whether it is in an island state. The protector117can be a breaker, and can be configured to perform an overcurrent protection and an electrical leakage protection. The protector117can be used as equipment for activating the protection of the system. For example, when the sensor115detects the island state, the protector117will be activated to turn off a connection between the power converting system100and the grid400.

As described above, the power converting system100of the present disclosure assembles input/output ports of the first converter111and the charging device130together. Therefore, house hold power distribution capacity does not have to be extended, such that the installation cost and the maintenance cost can be reduced. In addition, since multiple input/output ports are assembled, the volume and the weight can be decreased so as to achieve better thermal management, simpler connection, and so on. Besides, the power converting system100of the present disclosure includes the sensor115to detect the input/output of the charging device130, so as to satisfy requirements of the grid400to electricity consumption, electricity generation, and support.

In one embodiment, the power converting device110is a multi-port converting controller. For example, the power converting device110is a four port converting controller. A port is connected to the first power source200, a port is connected to the second power source300, a port is connected to the charging device130, and a port is connected to the protection device120. The above-mentioned ports can be disposed in the power converting device110according to the application and the real system construction. The power converting device110can be used to power convert, control direction of the power flow, communicate with the inner system, communicate with the outer system, protect the system, and power manage.

In one embodiment, the controller113is a controlling and communicating core of the whole power converting system100, which is used to implement a power conversion control, a communication with the inner system, a communication with the outer system, and a power management. The power conversion control can obtain the voltage and the current of the first power source200(e.g., photovoltaics panel) to calculate the power variation and the voltage variation so as to achieve the Maximum Power Point Tracking (MPPT) of the port of the first power source200. Simultaneously, the power conversion control can obtain the voltage and the current of the first power source200(e.g., photovoltaics panel) to calculate the powervariation and the voltage variation so as to control active power and reactive power of the alternative current to achieve the power factor control and the frequency control. The controller113can communicate with the charging device130and the movable energy storage device600for determining whether the movable energy storage device600(e.g., electric vehicle) operates at a charge mode or a discharge mode. The controller113can obtain the sampling signal of the sensor115, and calculate the power of the movable energy storage device600. The controller13can communicate with the protection device120, and control the power converting device110to switch between on-grid work mode and off-grid work mode. The controller113can be connected to Could through a router to achieve remote data feedback, monitor, and software update. Those functions can be achieved by one or multiple controllers.

In one embodiment, the charging device130includes a power converter, a controller, a relay or a contractor, a detector and a communicator. The charging device130can be an AC charger-typed connector. The power converter is a power converting portion to achieve DC/DC conversion function, for example, an auxiliary power. The power converter can be a power converting portion to achieve DC/AC conversion function, for example, the second converter610can be disposed in the charging device130. The controller can control the power converter, and the communicator can perform a communication between the movable energy storage device600and the controller113. The relay or a contactor can connect or cut off a connection between the power converting device110and the movable energy storage device600. The detector is used to detect related signals of the charging device130, and the related signals includes a voltage signal, a current signal, a power signal, and a temperature signal.

The power converting system100of the present disclosure can provide the best power management in any state. The power converting system100of the present disclosure can select at least one power source of the first power source, the second power source, the third power source and the grid to provide electricity to the load according to multiple preset modes. The above-mentioned power management will be described in detail in the embodiments ofFIG.3toFIG.6.

FIG.3depicts a detailed schematic diagram of operating a power converting system100according to one embodiment of the present disclosure. In this embodiment, the power converting system100works in a first mode. The first mode is that the power converting system100works during daytime, and the grid400can provide electricity. That is to say, the power converting system100is in an on-grid work mode and the power of the first power source200(e.g., photovoltaics panel) is higher. The power converting device110controls the first power source200to charge the second power source300(e.g., energy storage battery) and the third power source620(e.g., energy storage battery), and provide electricity to the load500. If there is still additional electricity, it can be provided to the grid400. If the need of the load500cannot be satisfied, the grid400can provide electricity to the load500.

If additional electricity cannot be used by the load500, cannot be stored in the second power source300(e.g., energy storage battery) and the third power source620(e.g., energy storage battery), and cannot be provided to the grid400, the power converting device110will limit the output power of the first power source200(e.g., photovoltaics panel).

FIG.4depicts a detailed schematic diagram of operating a power converting system100according to one embodiment of the present disclosure. In this embodiment, the power converting system100works in a second mode. The second mode is that the power converting system100works at night, and the grid400can provide electricity. That is to say, the power converting system100is in an on-grid work mode and the first power source200(e.g., photovoltaics panel) cannot generate electricity. The controller113collects voltage signals and current signals of all power ports of the power converting system100for obtaining related states, thereby adopting suitable electricity management. For example, electricity stored in the second power source300(e.g., energy storage battery) and the third power source620(e.g., energy storage battery) can be provided to the load500. If the need of the load500cannot be satisfied, the grid400can provide electricity to the load500.

In addition, if the power need by the load500is not high, the second power source300(e.g., energy storage battery) has the priority to provide electricity to the load500, so as to make sure that the movable energy storage device600(e.g., electric vehicle) always has electricity for using. If the movable energy storage device600shall be used tomorrow and electricity of the movable energy storage device600is lacking, the movable energy storage device600can be charged by the grid400during off-peak time so as to achieve greater benefits.

FIG.5depicts a detailed schematic diagram of operating a power converting system100according to one embodiment of the present disclosure. In this embodiment, the grid400stops providing electricity, so the power converting system100works in an off-grid work mode. At this time, the controller113detects an island state through the sensor115, and controls the protector117to turn off a connection between the power converting system100and the grid400. The way to detect the island state can be active island detection or inactive island detection. In addition, the way to detect the island state can be performed through obtaining the voltage and the frequency of the grid400.

Besides, the protection device120can switch the power converting system100from an on-grid work mode to an off-grid work mode through the switch121inFIG.2. The switch between the on-grid work mode and the off-grid work mode not only can be performed by the power converting system100actively, but also can be performed manually. After accessing the off-grid work mode, the power converting system100can continuously provide electricity to the load500for the need of emergency electricity and continuous electricity, for example, emergency lighting, refrigerator, and so on.

In some embodiments, the power converting system100works in a third mode. The third mode is that the power converting system100works at daytime and the grid400stops providing electricity. That is to say, the power converting system100is in an off-grid work mode and the power of the first power source200(e.g., photovoltaics panel) is high. The power converting device110controls the first power source200to provide electricity to the load500. If there is still additional electricity, the second power source300(e.g., energy storage battery) and the third power source620(e.g., energy storage battery) can be charged selectivity. If additional electricity is not used by the load500, and cannot be stored in the second power source300and the third power source620, the power converting device110will limit the output power of the first power source200. Besides, if the power of the first power source200is not enough to provide electricity to the load500, the second power source300and/or the third power source620can be used to provide electricity to the load500.

FIG.6depicts a detailed schematic diagram of operating a power converting system100according to one embodiment of the present disclosure. In this embodiment, the power converting system100works in a fourth mode. The fourth mode is that the power converting system100works at night, and the grid400stops providing electricity. That is to say, the power converting system100is in an off-grid work mode and the first power source200(e.g., photovoltaics panel) cannot generate electricity. The second power source300(e.g., energy storage battery) and/or the third power source620(e.g., energy storage battery) can provide electricity to the load500. If the need for the power of the load500is not high, the controller113will control the second power source300to provide electricity to the load500so as to ensure that the movable energy storage device600(e.g., electric vehicle) has electricity for usage at any time.

FIG.7depicts a schematic diagram of a power converting system100according to one embodiment of the present disclosure. Compared to the power converting system100inFIG.1, the sensor115of the power converting system100inFIG.7is not electrically connected to the charging device130in a direct way. At this time, the sensor115obtains signals at a public point of the first converter111and the charging device130indirectly, and the related information of the charging device130can be obtained through calculation.

FIG.8depicts a schematic diagram of the first converter111of the power converting device110of the power converting system100shown inFIG.7according to one embodiment of the present disclosure. As shown in the figure, the first converter111of the power converting device110includes a first sub-converter112, a second sub-converter114, a DC bus116, and a third sub-converter118.

In one embodiment, the first sub-converter112is coupled to the first power source200and the DC bus116, and configured to receive and adjust a power provided by the first power source200. For example, the first sub-converter112can be a unidirectional DC-DC converter, such as a boost converter, and the first power source200can be a DC power source. The unidirectional DC-DC converter112is configured to receive the power provided by the DC power source200and convert a port voltage of the DC power source200to fit the voltage of the DC bus116.

In one embodiment, the second sub-converter114is coupled to the second power source300and the DC bus116. The second sub-converter114is configured to receive and adjust a power provided by the second power source300, or configured to charge the second power source300. For example, the second sub-converter114can be a bidirectional DC-DC converter, such as a Dual Active Bridge (DAB) series resonance converter, and the second power source300can be a DC power source. The bidirectional DC-DC converter114is configured to receive the power provided by the DC power source300and convert a port voltage of the DC power source300to fit the voltage of the DC bus116, or configured to charge the DC power source300. The third sub-converter118is coupled to the DC bus116, and the third sub-converter118is coupled to the protection device120through the sensor115and the protector117. For example, the third sub-converter118can be a bidirectional DC-AC converter. The bidirectional DC-AC converter may be configured to receive the AC power from the grid400and convert the AC power into a DC power. The DC power obtained can be used to charge the second power source (e.g., high-voltage batteries) and/or the movable energy storage device (e.g., electric vehicle). The bidirectional DC-AC converter may be configured to receive the DC power from at least one DC power source and convert the DC power into a AC power. The AC power obtained can be provided to the grid400or the load500, or be used to charge the movable energy storage device (e.g., electric vehicle).

FIG.9depicts a schematic diagram of a power converting system100according to one embodiment of the present disclosure. As shown inFIG.9, the power converting device110of the power converting system100includes plural input/output ports. An input/output port of the power converting device110is electrically connected to the first power source200, an input/output port of the power converting device110is electrically connected to the second power source300. In addition, another input/output port of the power converting device110is electrically connected to the protection device120, and the power converting device110is electrically connected to the grid400and the load500through the protection device120. Besides, still another input/output port of the power converting device110is electrically connected to the charging device130, and the power converting device110is electrically connected to the movable energy storage device600through the charging device130.

For example, the first power source200can be Photovoltaics (PV) device. Therefore, the first power source200can be configured to convert solar energy into electrical energy, and provide the electrical energy to the power converting device110. The second power source300can be an energy storage battery. Therefore, the second power source300can be configured to store electrical energy provided by the power converting device110, and provide electrical energy to the power converting device110when needed.

The charging device130inFIG.1is coupled to the protector117. For example, in one embodiment, the charging device130is coupled to an AC side of the power converting device110, and is electrically connected to the protection device120through the protector117, and further electrically connected to the grid400through the protection device120. The charging device130inFIG.9is coupled to the DC bus116of the power converting device110. Therefore, the third power620inFIG.9does not need the second converter610inFIG.1. Accordingly, the controller113of the power converting system100can detect current, voltage, and/or power in the DC bus116to control a state of the port connected to the charging device130, thereby satisfying the requirements of the movable energy storage device600. In this embodiment, the charging device130includes a power converter, a controller, a relay or contactor, a detector, and a communicator. The charging device130can be a DC charging gun. The power converter is a part of the power conversion. The power converter can implement DC/DC conversion, for example supplying auxiliary power.

In the prior art, the charging device is coupled to a grid through a distribution board. In the present disclosure, the charging device130is coupled to AC side or DC bus of the power converting system110, and the charge equipment (for example, electric vehicle) does not need to use grid-connected capacity independently. The power converting system of the present disclosure can integrate solar energy, storage energy, and charge energy. When introducing the charging equipment, the solar energy and energy storage equipment will be considered, so as to enhance usage efficiency of renewable energy.

FIG.10depicts a schematic diagram of the first converter111of the power converting device110of the power converting system100shown inFIG.9according to one embodiment of the present disclosure. As shown inFIG.10, the first converter111of the power converting device110incudes a first sub-converter112, a second sub-converter114, a DC bus116, a third sub-converter118, and a fourth sub-converter119.

Compared withFIG.8, the first converter111of the power converting device110inFIG.10further includes a fourth sub-converter119. The fourth sub-converter119is coupled to the DC bus116and the charging device130. The fourth sub-converter119receives a power provided by the third power source620through the charging device130and converts the power provided by the third power source620to fit the DC bus116, or charges the third power source620through the charging device130. For example, the fourth sub-converter119can be a bidirectional DC-DC converter, such as a DAB series resonance converter, and the third power source620can be DC power source. The bidirectional DC-DC converter119is configured to receive the power provided by the DC power source620, or configured to charge the DC power source620. Therefore, the third power source620inFIG.10does not need the second converter610inFIG.1to transform DC electrical energy into AC electrical energy.

FIG.11depicts a schematic diagram of the first converter111of the power converting device110of the power converting system100shown inFIG.9according to one embodiment of the present disclosure. Compared withFIG.10, the first converter111of the power converting device110inFIG.11further includes a sensor121. The sensor121is coupled to the DC bus116. The sensor121can be configured to at least detect the state of the DC bus116.

FIG.12depicts a schematic diagram of the first converter111of the power converting device110of the power converting system100shown inFIG.9according to one embodiment of the present disclosure. Compared withFIG.10, the power converting device110inFIG.12does not need the second sub-converter114, and the power of the second power300can be transmitted to the DC bus116directly.

FIG.13depicts a schematic diagram of the first converter111of the power converting device110of the power converting system100shown inFIG.12according to one embodiment of the present disclosure. As shown inFIG.13, the first sub-converter112is coupled to the first power source200. The DC bus116can be directly coupled to the second power source300. The third sub-converter118is coupled to the DC bus116, and the third sub-converter118is coupled to the protection device120through the sensor115and the protector117. The fourth sub-converter119is coupled to the DC bus116and the charging device130.

In one embodiment, the controller113of the first converter111of the power converting device110can be implemented by plural controllers, for example, controllers1111,1112,1113. The controller1111can be configured to collect signals of nodes N1, N2, N3for controlling the first sub-converter112and the third sub-converter118. The controller1112can be configured to collect signals of nodes N4, N5for controlling the fourth sub-converter119. The controller1113is mainly configured to communicate with other devices. For example, the controller1113collects signals of the second power source300and the third power source620, and communicates with the controller1111and the controller1112.

In one embodiment, the first converter111of the power converting device110sets the sensor at the node N2or the node N5. The sensor at the node N2or the node N5is configured to detect signals of the DC bus116, and transmit the signals detected to the controllers1111,1112. Meanwhile, the third sub-converter118and the fourth sub-converter119can share the sensor so as to reduce the cost of the hardware.

When the sensor is at the node N2, the signals detected by the sensor are transmitted to the controller1112through a long distance, and as a result, the signals are interfered during the transmitting process. When the sensor is at the node N5, the signals detected by the sensor are transmitted to the controller1111through a long distance, and as a result, the signals are interfered during the transmitting process. In another embodiment, the first converter111of the power converting device110sets the sensors122,123at the node N2and the node N5, and each of the sensors122,123is configured to detect the signals of the DC bus116. The sensor122at the node N2only needs to transmit the signals detected to the controller1111nearby, and the sensor123at the node N5only needs to transmit the signals detected to the controller1112nearby, thereby avoiding interference during the transmitting process.

FIG.14depicts a schematic diagram of the power converting device110of the power converting system100shown inFIG.9according to one embodiment of the present disclosure. As shown inFIG.14, the power converting system includes a first sub-converter112, a DC bus116, a third sub-converter118, and a fourth sub-converter119. The first power source200can be Photovoltaics (PV) panel, the second power source300can be energy storage batteries (BAT), and the grid400can be single-phase AC grid. The charging device130can be a connector coupled to the movable energy storage device (such as electric vehicle) and the fourth sub-converter119. The first sub-converter112can be a unidirectional DC-DC converter, for example, a boost converter. The DC bus116can be bus capacitors Cbus. The third sub-converter118can be a bidirectional DC-AC inverter. The fourth sub-converter119can be a bidirectional DC-DC converter, for example, a Dual-Active Bridge Series Resonant Converter (DAB-SRC).

The power converting system of the present disclosure can perform a compensation to the output of the charging device according to the signals detected. Besides, the controllers of the power converting device controls the multiple converters according to the signals detected so as to achieve the best power management. In addition, since input/output ports of the power converting device and the charging device are assembled together, volume and weight of the power converting system is reduced so as to achieve better thermal management, simpler connection, and so on.