Non-contact electricity supply device

A power-supply-side coil receives an alternating current from an AC power source to produce a magnetic flux. A power-supply-side capacitor is connected in parallel with the power-supply-side coil. A power-supply-side filter circuit includes a reactor and a capacitor, which are connected in series between the AC power source and the power-supply-side coil. A power-receiving-side coil is interlinked with a magnetic flux produced by the power-supply-side coil to produce an alternating current. The power-supply-side filter circuit, the power-supply-side capacitor, and the power-supply-side form a circuit having an impedance having a frequency characteristic, in which a frequency of a minimum point formed on a high-frequency side relative to a maximum point is greater than a frequency of a fundamental wave of an alternating current supplied from the AC power source and is less than a frequency of a third order wave of the fundamental wave.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on reference Japanese Patent Application No. 2013-57790 filed on Mar. 21, 2013, the disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a non-contact electricity supply device including a power-supply-side coil, a power-receiving-side coil, a power-supply-side capacitor for a resonant circuit, and a power-supply-side filter circuit.

BACKGROUND

For example, a patent document 1 discloses a conventional non-contact electricity supply device including a power-supply-side coil, a power-receiving-side coil, a power-supply-side capacitor for a resonant circuit, and a power-supply-side filter circuit.

The non-contact electricity supply device includes a primary winding and a secondary winding. The non-contact electricity supply device further includes a capacitor for a resonant circuit and a filter circuit.

The primary winding is an element supplied with an alternating current from a high frequency AC power source to produce an alternating magnetic flux. The secondary winding is an element interlinked with the alternating magnetic flux, which is produced by the primary winding, to produce an alternating current. The capacitor is an element, which configures a resonant circuit with the primary winding. The capacitor is connected in parallel with the primary winding. The filter circuit removes a predetermined frequency component, which is included in an alternating current supplied from the high frequency AC power source. The filter circuit is configured with a coil and a capacitor, which are connected in series with each other. The filter circuit is connected between the high frequency AC power source and the primary winding.

A circuit, which is configured with the filter circuit, the capacitor, and the primary winding, has an impedance having a frequency characteristic including one maximum point and two minimum points. One of the two minimum point is caused by a resonance of a circuit, which is configured with the filter circuit and the primary winding. The one of the two minimum points is formed on the low frequency side relative to a frequency of the maximum point. The other of the two minimum points is caused by a resonance of a circuit, which is configured with the filter circuit and the capacitor. The other minimum point is formed on a high frequency side relative to the frequency of the maximum point.

The high frequency AC power source supplies an alternating current in a rectangular waveform. Therefore, the alternating current supplied from the high frequency AC power source includes a frequency component of a fundamental wave and odd-order harmonics components of the fundamental wave. In general, the frequency of the fundamental wave of the alternating current supplied from the high frequency AC power source is set at a frequency close to the maximum point to suppress an electric current to be supplied.

PATENT DOCUMENT 1

Publication of Unexamined Japanese Patent Application No. 2012-105503

It is assumable that a circuit, which is configured with the filter circuit, the capacitor, and the primary winding, has an impedance having a frequency characteristic. In this frequency characteristic, it is further assumed that the frequency of the minimum point, which is formed on the high frequency side relative to the maximum point, coincides with the frequency of the third order wave of the fundamental wave. In such a case, an electric current of the third order harmonics component, which has the largest amplitude in the odd-order harmonics components and is ineffective to power supply, may increase. Consequently, a loss may increase in power supply.

SUMMARY

It is an object of the present disclosure to produce a non-contact electricity supply device configured to suppress a loss caused by a harmonics component included in an alternating current supplied from an AC power source.

According to an aspect of the present disclosure, a non-contact electricity supply device comprises a power-supply-side coil configured to receive an alternating current, which is supplied from an AC power source to produce a magnetic flux. The non-contact electricity supply device further comprises a power-supply-side capacitor connected in parallel with the power-supply-side coil to form, with the power-supply-side coil, a resonant circuit. The non-contact electricity supply device further comprises a power-supply-side filter circuit connected between the AC power source and the power-supply-side coil, to which the power-supply-side capacitor is connected, the power-supply-side filter circuit including a reactor and a capacitor, which are connected in series. The non-contact electricity supply device further comprises a power-receiving-side coil configured to be interlinked with a magnetic flux produced by the power-supply-side coil to produce an alternating current. The capacitance of the capacitor and the inductance of the reactor of the power-supply-side filter circuit, the capacitance of the power-supply-side capacitor, and the inductance of the power-supply-side coil are set, such that, a circuit, which includes the power-supply-side filter circuit, the power-supply-side capacitor, and the power-supply-side coil, has an impedance having a frequency characteristic, in which a frequency of a minimum point, which is formed on a high-frequency side relative to a maximum point, is greater than a frequency of a fundamental wave of an alternating current supplied from the AC power source and is less than a frequency of a third order wave of the fundamental wave.

DETAILED DESCRIPTION

As follows, embodiments of the present disclosure will be described in detail. In the present embodiment, a non-contact electricity supply device according to the present disclosure is employed for supplying electricity to a vehicular battery, which is equipped to an electric vehicle and/or a hybrid vehicle, with a non-contact configuration.

First Embodiment

First, a configuration of the non-contact electricity supply device according to the first embodiment will be described with reference toFIG. 1.

As shown inFIG. 1, a non-contact electricity supply device1has a non-contact electricity supply configuration to transmit electricity from a commercial power source (AC power source) AC1outside a vehicle to a vehicular battery B1equipped in the vehicle, thereby to charge the vehicular battery B1. The non-contact electricity supply device1includes a power-supply-side coil10, a power-supply-side capacitor11, a power-receiving-side coil12, a power-receiving-side capacitor13, a power supply circuit (AC power source)14, a power-supply-side filter circuit15, a power receiving circuit16, and a control circuit17.

The power-supply-side coil10is an element to produce an alternating magnetic flux when being supplied with by an alternating current. The power-supply-side coil10is located at a predetermined position in (or on) an earth surface of a parking space.

The power-supply-side capacitor11is an element, which configures a resonant circuit with the power-supply-side coil10. The power-supply-side capacitor11is connected in parallel with the power-supply-side coil10.

The power-receiving-side coil12is an element interlinked with the power-supply-side coil10to receive the alternating magnetic flux produced by the power-supply-side coil10thereby to implement electromagnetic induction to produce an alternating current. The power-receiving-side coil12is equipped to a bottom of the vehicle such that the power-receiving-side coil12is opposed to the power-supply-side coil10with a space in the vertical direction when the vehicle is parked at the parking space.

The power-receiving-side capacitor13is an element, which configures a resonant circuit with the power-receiving-side coil12. The power-receiving-side capacitor13is connected in parallel with the power-receiving-side coil12.

In such a configuration, an inductance of the power-supply-side coil10and an inductance of the power-receiving-side coil12are set in consideration of a size of the parking space, a size of the vehicle, the space between the earth surface of the parking space and the bottom of the vehicle, and/or the like. A capacitance of the power-supply-side capacitor11and a capacitance of the power-receiving-side capacitor13are set, such that a power factor of an alternating current supplied from the power supply circuit14to the power-supply-side coil10, to which the power-supply-side capacitor11is connected, becomes 1, when the power-supply-side coil10and the power-receiving-side coil12are in a predetermined reference opposed state. Alternatively, the capacitance of the power-supply-side capacitor11and the capacitance of the power-receiving-side capacitor13are set within a range, in which the capacitances can be set, such that the power factor of the alternating current becomes a value close to 1, as much as possible.

The power supply circuit14converts an alternating current supplied from the commercial power source AC1into an alternating current at a high frequency. The power supply circuit14further supplies the converted alternating current to the power-supply-side coil10, to which the power-supply-side capacitor11is connected. The power supply circuit14includes a power-supply-side converter circuit140and an inverter circuit141.

The power-supply-side converter circuit140converts an alternating current supplied from the commercial power source AC1into a direct current and supplies the converted direct current to an inverter circuit141. The power-supply-side converter circuit140is configured with a rectification circuit and a DC/DC converter circuit. The rectification circuit includes diodes in a bridge connection. The power-supply-side converter circuit140is connected to both the commercial power source AC1and the inverter circuit141.

The inverter circuit141converts a direct current, which is supplied from the power-supply-side converter circuit140, into an alternating current, which is in a rectangular waveform and at a high frequency. The inverter circuit141further supplies the converted alternating current through the power-supply-side filter circuit15to the power-supply-side coil10, to which the power-supply-side capacitor11is connected. The inverter circuit141includes IGBTs in a bridge connection. Each of the IGBTs is connected in anti-parallel with a freewheel diode (flywheel diode). The IGBTs are switched thereby to convert a direct current, which is supplied from the power-supply-side converter circuit140, into an alternating current, which is in a rectangular waveform and at a high frequency. The converted alternating current is further supplied though the power-supply-side filter circuit15to the power-supply-side coil10, to which the power-supply-side capacitor11is connected. The inverter circuit141is connected to the power-supply-side converter circuit140. The inverter circuit141is further connected through the power-supply-side filter circuit15to the power-supply-side coil10, to which the power-supply-side capacitor11is connected.

The power-supply-side filter circuit15removes a predetermined frequency component included in an alternating current supplied from the inverter circuit141. The power-supply-side filter circuit15includes a reactor150and a capacitor151, which are connected in series. The power-supply-side filter circuit15is connected between the inverter circuit141and the power-supply-side coil10, to which the power-supply-side capacitor11is connected.

As shown inFIG. 2, a circuit, which is configured with the power-supply-side filter circuit15, the power-supply-side capacitor11, and the power-supply-side coil10, has an impedance having a frequency characteristic viewed from the power supply circuit14. The frequency characteristic shown inFIG. 2includes one maximum point A and two minimum points B and C. The minimum point B is formed due to a resonance caused by a circuit, which is configured with the power-supply-side filter circuit15and the power-supply-side coil10. The minimum point B is formed on a low frequency side relative to the maximum point A at a frequency fa. The minimum point C is formed due to a resonance caused by a circuit, which is configured with the power-supply-side filter circuit15and the power-supply-side capacitor11. The minimum point C is formed on a high frequency side relative to the maximum point A at the frequency fa.

In the present configuration ofFIG. 1, the inductance of the reactor150and the capacitance of the capacitor151are set, such that a frequency fc of the minimum point C inFIG. 2is greater than a frequency f0of a fundamental wave of an alternating current, which is in a rectangular waveform and supplied from the inverter circuit141, and the frequency fc is less than a frequency of a third order wave of the fundamental wave. More specifically, the inductance of the reactor150and the capacitance of the capacitor151are set, such that the frequency fc is greater than the frequency f0of the fundamental wave, and the frequency fc is less than a frequency of a second order wave of the fundamental wave. More specifically, the inductance of the reactor150and the capacitance of the capacitor151are set, such that the frequency fc is 1.7 times the frequency f0of the fundamental wave.

The frequency fc of the minimum point C can be set by modifying the inductance of the power-supply-side coil10and the capacitance of the power-supply-side capacitor11. However, the inductance of the power-supply-side coil10and the capacitance of the power-supply-side capacitor11may not be freely modified because of other constraints, and therefore, the frequency fc is set by modifying the inductance of the reactor150and the capacitance of the capacitor151.

Referring back toFIG. 1, the power receiving circuit16converts an alternating current supplied from the power-receiving-side coil12, to which the power-receiving-side capacitor13is connected, into a direct current. The power receiving circuit16further supplies the converted direct current to the vehicular battery B1. The power receiving circuit16includes a rectification circuit160and a power-receiving-side converter circuit161.

The rectification circuit160rectifies an alternating current supplied from the power-receiving-side coil12, to which the power-receiving-side capacitor13is connected, to convert the alternating current into a direct current. The rectification circuit160further supplies the converted direct current to the power-receiving-side converter circuit161. The rectification circuit160includes diodes in a bridge connection. The rectification circuit160is connected to the power-receiving-side coil12, to which the power-receiving-side capacitor13is connected. The rectification circuit160is further connected to the power-receiving-side converter circuit161.

The power-receiving-side converter circuit161converts a direct current supplied from the rectification circuit160into a direct current from at a different voltage. The power-receiving-side converter circuit161further supplies the converted direct current to the vehicular battery B1. The power-receiving-side converter circuit161is configured with a DC/DC converter circuit. The power-receiving-side converter circuit161is connected to both the rectification circuit160and the vehicular battery B1.

The control circuit17controls the power supply circuit14and the power receiving circuit16to control power supply from the commercial power source AC1to the vehicular battery B1. The control circuit17includes a power-supply-side control circuit170and a power-receiving-side control circuit171.

The power-supply-side control circuit170exchanges information, which is need for control, with the power-receiving-side control circuit171via wireless communications, thereby to implement the control of the power-supply-side converter circuit140and the inverter circuit141. The power-supply-side control circuit170is connected to both the power-supply-side converter circuit140and the inverter circuit141.

The power-receiving-side control circuit171exchanges information, which is needed for control, with the power-supply-side control circuit170via wireless communications, thereby to implement the control of the power-receiving-side converter circuit161. The power-receiving-side control circuit171is connected to the power-receiving-side converter circuit161.

Subsequently, an operation of the non-contact electricity supply device will be described with reference toFIGS. 1 to 3.

When the vehicle is parked at a parking space, the power-supply-side coil10and the power-receiving-side coil12shown inFIG. 1are opposed to each other and are located at a relative position in a predetermined range in the vertical direction, in the front-back direction, and in the horizontal direction. In the present state, a charge start button (not shown) is operated to instruct the non-contact electricity supply device1to start a charging operation.

The power-supply-side converter circuit140is controlled by the power-supply-side control circuit170to convert an alternating current supplied from the commercial power source AC1into a direct current and to supply the converted direct current to the inverter circuit141. The inverter circuit141is controlled by the power-supply-side control circuit170to convert a direct current supplied from the power-supply-side converter circuit140into an alternating current, which is in a rectangular waveform and at a high frequency, such as tens of kHz. Thus, the inverter circuit141supplies the converted alternating current through the power-supply-side filter circuit15to the power-supply-side coil10, to which the power-supply-side capacitor11is connected. The power-supply-side filter circuit15removes a predetermined frequency component, which is included in the alternating current supplied from the inverter circuit141. The power-supply-side coil10, to which the power-supply-side capacitor11is connected, is supplied with an alternating current from the inverter circuit141thereby to generate an alternating magnetic flux.

As shown inFIG. 2, the circuit, which is configured with the power-supply-side filter circuit15, the power-supply-side capacitor11, and the power-supply-side coil10, has an impedance having the frequency characteristic. In the frequency characteristic, the frequency fc of the minimum point C is set at a value, which is 1.7 times the frequency of the fundamental wave of an alternating current, which is in a rectangular waveform and supplied from the inverter circuit141. Therefore, as shown inFIG. 3, a third order harmonics component of a fundamental wave of an electric current can be suppressed, and therefore, an alternating current close to a fundamental wave can be produced.

As shown inFIG. 1, the power-receiving-side coil12, to which the power-receiving-side capacitor13is connected, is interlinked with the alternating magnetic flux generated by the power-supply-side coil10thereby to implement an electromagnetic induction to produce an alternating current. The rectification circuit160receives an alternating current supplied from the power-receiving-side coil12, to which the power-receiving-side capacitor13is connected, and rectifies the received alternating current to convert the received alternating current into a direct current. The rectification circuit160further supplies the converted direct current to the power-receiving-side converter circuit161. The power-receiving-side converter circuit161is controlled by the power-receiving-side control circuit171to convert a direct current, which is supplied from the rectification circuit160, into a direct current at a different voltage. The power-receiving-side converter circuit161further supplies the converted direct current to the vehicular battery B1to charge the vehicular battery B1. In such a way, electricity can be transmitted from the commercial power source AC1to the vehicular battery B1in the non-contact configuration.

Subsequently, an operation effect of the present configuration will be described.

The alternating current supplied from the inverter circuit141is in a rectangular waveform. Therefore, the supplied alternating current contains a frequency component of the fundamental wave and an odd-order harmonics component of the fundamental wave. A condition will be assumed with reference toFIG. 4. InFIG. 4, the frequency fc of the minimum point C coincides with a frequency of a third order wave of the fundamental wave in a frequency characteristic of impedance of the circuit, which is configured with the power-supply-side filter circuit15, the power-supply-side capacitor11, and the power-supply-side coil10. In such a case, as shown inFIG. 5, an electric current of a third order harmonics component increases. The electric current of the third order harmonics component has the largest amplitude among odd-order harmonics components and is not effective to power supply.

It is noted that, according to the first embodiment, as shown inFIG. 2, the inductance of the reactor150, the capacitance of the capacitor151, the capacitance of the power-supply-side capacitor11, and the inductance of the power-supply-side coil10in the power-supply-side filter circuit15are set, such that the frequency fc of the minimum point C becomes greater than the frequency f0of the fundamental wave, and the frequency fc becomes less than the frequency of the third order wave of the fundamental wave. Therefore, an impedance can be increased relative to the third order harmonics component of the fundamental wave. Thus, as shown inFIG. 3, it is possible to suppress increase in an electric current of the third order harmonics component, which has the largest amplitude among odd-order harmonics components and is not effective to power supply. The present configuration enables to suppress a loss caused by a harmonics component contained in an alternating current supplied from the inverter circuit141.

In a case where an alternating current supplied from the inverter circuit141is offset to a positive side or to a negative side, the alternating current contains an even-order harmonics of the fundamental wave.

It is noted that, according to first embodiment, as shown inFIG. 2, the frequency fc of the minimum point C is set at a frequency other than a frequency of a second order wave of the fundamental wave. Therefore, an impedance can be increased relative to the second order harmonics component of the fundamental wave. Thus, it is possible to suppress increase in an electric current of the second order harmonics component, which has the largest amplitude among even-order harmonics components and is not effective to power supply. The present configuration enables to suppress a loss caused by a harmonics component, even in a case where an alternating current supplied from the inverter circuit141is offset to the positive side or to the negative side to contain an even-order harmonics component.

According to the first embodiment, the frequency fc of the minimum point C is set to be greater than the frequency f0of the fundamental wave and to be less than the frequency of the second order wave of the fundamental wave. Therefore, an impedance can be increased relative to a harmonics component higher in frequency than the second order harmonics component of the fundamental wave. Thus, the present configuration enables to suppress emission of a noise.

According to the first embodiment, the frequency fc of the minimum point C is set to be 1.7 times the frequency of the fundamental wave, nevertheless, the present disclosure is not limited to this example. For example, the frequency fc of the minimum point C may be set to be 1.5 times the frequency of the fundamental wave.

According to the first embodiment, the frequency fc of the minimum point C is set to be greater than the frequency f0of the fundamental wave and to be less than the frequency of the second order wave of the fundamental wave, nevertheless, the present disclosure is not limited to this example. The frequency fc of the minimum point C may be set to be greater than the frequency of the second order wave of the fundamental wave and to be less than the frequency of the third order wave of the fundamental wave. For example, the frequency fc of the minimum point C may be set to be 2.5 times the frequency of the fundamental wave. In a case where the frequency fc of the minimum point C is set by modifying the inductance of the reactor150of the power-supply-side filter circuit15, when the inductance of the reactor150is decreased, the frequency fc of the minimum point C increases. Therefore, the inductance of the reactor150can be decreased, compared with a configuration in which the frequency fc of the minimum point C is set to be greater than the frequency f0of the fundamental wave and to be less than the frequency of the second order wave of the fundamental wave. That is, the number of turn can be decreased in the reactor150. The present configuration enables to suppress a loss and to enhance an efficiency.

Furthermore, in the example according to the first embodiment, since the inductance of the power-supply-side coil10and the capacitance of the power-supply-side capacitor11cannot be modified freely due to other constraints, the inductance of the reactor150of the power-supply-side filter circuit15and the capacitance of the capacitor151are modified to set the frequency fc of the minimum point C. It is noted that, the present disclosure is not limited to this example. In a configuration where the inductance of the power-supply-side coil10and the capacitance of the power-supply-side capacitor11can be modified freely, the inductance of the power-supply-side coil10and the capacitance of the power-supply-side capacitor11may be modified to set the frequency fc of the minimum point C.

In the example of the first embodiment, the non-contact electricity supply device related to the present disclosure is employed in the non-contact configuration to transmit an electricity to the vehicular battery equipped in an electric vehicle or a hybrid vehicle. It is noted that, the present disclosure is not limited to this example. The non-contact electricity supply device related to the present disclosure may be employed in a non-contact configuration to transmit an electricity to a home appliance.

Second Embodiment

Subsequently, a non-contact electricity supply device according to the second embodiment will be described. In the first embodiment, the non-contact electricity supply device includes the power-supply-side filter circuit including the one pair of the reactor and the capacitor, which are connected in series with each other. To the contrary, the non-contact electricity supply device according to the second embodiment includes a power-supply-side filter circuit including two pairs each including a reactor and a capacitor, which are connected in series with each other.

The configuration of the non-contact electricity supply device of the second embodiment will be described with reference toFIG. 6.

The non-contact electricity supply device2shown inFIG. 6has a non-contact configuration to transmit an electricity from a commercial power source (AC power source) AC2outside the vehicle to a vehicular battery B2thereby to charge the vehicular battery B2. The non-contact electricity supply device2includes a power-supply-side coil20, a power-supply-side capacitor21, a power-receiving-side coil22, a power-receiving-side capacitor23, a power supply circuit (AC power source)24, a power-supply-side filter circuit25, a power receiving circuit26, and a control circuit27.

The power-supply-side coil20, the power-supply-side capacitor21, the power-receiving-side coil22, the power-receiving-side capacitor23, and the power supply circuit24have configurations substantially equivalent to the configurations of the power-supply-side coil10, the power-supply-side capacitor11, the power-receiving-side coil12, the power-receiving-side capacitor13, and the power supply circuit14of first embodiment, respectively.

The power-supply-side filter circuit25is configured with two pairs including a reactor250and a capacitor251, which are connected in series, and a reactor252and a capacitor253, which are connected in series. The inductance of the reactor250is equivalent to the inductance of the reactor252. The capacitance of the capacitor251is equivalent to the capacitance of the capacitor253. The reactor250and the capacitor251are connected between one output end of an inverter circuit241and one end of the power-supply-side coil20, to which the power-supply-side capacitor21is connected. The reactor252and the capacitor253are connected between the other output end of the inverter circuit241and the other end of the power-supply-side coil20, to which the power-supply-side capacitor21is connected.

The power receiving circuit26and the control circuit27have configurations, which are substantially equivalent to the configurations of the power receiving circuit16and the control circuit17of the first embodiment.

The operation of the second embodiment is substantially equivalent to the operation of the first embodiment, and therefore, description of the operation is omitted.

Subsequently, an operation effect of the second embodiment will be described.

The power-supply-side filter circuit25according to second embodiment is configured with the two pairs of the reactors and capacitors, which are connected in series and have substantially the same inductance and the capacitance. The reactor250and the capacitor251are connected between the one output end of the inverter circuit241and the one end of the power-supply-side coil20, to which the power-supply-side capacitor21is connected. The reactor252and the capacitor253are connected between the other output end of the inverter circuit241and the other end of the power-supply-side coil20, to which the power-supply-side capacitor21is connected. It is assumable a case where an earth capacitance varies in one of the pair of paths, which is from the inverter circuit241through the power-supply-side filter circuit25and wiring cables to the one end and the other end of the power-supply-side coil20. Even in such a case, in the present configuration, a predetermined frequency component can be removed in the other path. Therefore, an influence due to a noise can be suppressed.

Third Embodiment

Subsequently, a non-contact electricity supply device according to the third embodiment will be described. As described above, the non-contact electricity supply device of the first embodiment transmits an electricity from the commercial power source to the vehicular battery. To the contrary, a non-contact electricity supply device according to the third embodiment has configurations of the power supply circuit and the power receiving circuit and causes a control circuit to implement a control, which are partially modified from those of the first embodiment, thereby to enable transmission of an electricity from the vehicular battery to the commercial power source.

The configuration of the non-contact electricity supply device of the third embodiment will be described with reference toFIG. 7.

The non-contact electricity supply device3shown inFIG. 7has a non-contact configuration to transmit an electricity from a commercial power source (AC power source) AC3to a vehicular battery B2thereby to charge the vehicular battery B3. The non-contact configuration of the non-contact electricity supply device3further enables to transmit an electricity from the vehicular battery B3to the commercial power source AC3thereby to supply an electric power to the commercial power source AC3. The non-contact electricity supply device3includes a power-supply-side coil30, a power-supply-side capacitor31, a power-receiving-side coil32, a power-receiving-side capacitor33, a power supply circuit (AC power source)34, a power-supply-side filter circuit35, a power receiving circuit36, and a control circuit37. The non-contact electricity supply device3further includes a power-receiving-side filter circuit38.

The power-supply-side coil30, the power-supply-side capacitor31, the power-receiving-side coil32, and the power-receiving-side capacitor33have configurations substantially equivalent to the configurations of the power-supply-side coil10, the power-supply-side capacitor11, the power-receiving-side coil12, and the power-receiving-side capacitor13of first embodiment, respectively.

The power supply circuit34converts an alternating current, which is supplied from the commercial power source AC3, into an alternating current at a high frequency. The power supply circuit34further supplies the converted alternating current to the power-supply-side coil30, to which the power-supply-side capacitor31is connected. The power supply circuit34further converts an alternating current, which is supplied from the power-supply-side coil30to which the power-supply-side capacitor31is connected, into a direct current. The power supply circuit34further supplies the converted direct current to the commercial power source AC3. The power supply circuit34includes a power-supply-side converter circuit340and an inverter circuit341.

The power-supply-side converter circuit340converts an alternating current, which is supplied from the commercial power source AC3, into a direct current. The power-supply-side converter circuit340further supplies the converted direct current to the inverter circuit341. The power-supply-side converter circuit340further converts a direct current, which is supplied from the inverter circuit341, into an alternating current. The power-supply-side converter circuit340further supplies the converted alternating current to the commercial power source AC3. The power-supply-side converter circuit340is configured with a rectification circuit and a bidirectional DC/DC converter circuit. The rectification circuit includes IGBTs in a bridge connection. Each of the IGBTs is connected in anti-parallel with a freewheel diode (flywheel diode). The power-supply-side converter circuit340rectifies an alternating current, which is supplied from the commercial power source AC3, by using the freewheel diodes to convert the supplied alternating current into a direct current. The power-supply-side converter circuit340causes the bidirectional DC/DC converter circuit to further convert the converted direct current into a direct current at a different voltage. Thus, the power-supply-side converter circuit340supplies the converted direct current to the inverter circuit341. The power-supply-side converter circuit340is further configured to cause the bidirectional DC/DC converter circuit to convert a direct current, which is supplied from the inverter circuit341, into a direct current at a different voltage. The power-supply-side converter circuit340is further configured to implement a switching operation of the IGBTs to convert the direct current into an alternating current. Thus, the power-supply-side converter circuit340supplies the converted alternating current to the commercial power source AC3. The power-supply-side converter circuit340is connected to both the commercial power source AC3and the inverter circuit341.

The inverter circuit341converts a direct current, which is supplied from the power-supply-side converter circuit340, into an alternating current, which is in a rectangular waveform and at a high frequency. The inverter circuit341further supplies the converted alternating current to the power-supply-side coil30, to which the power-supply-side capacitor31is connected. The inverter circuit341is further configured to rectify an alternating current, which is supplied from the power-supply-side coil30to which the power-supply-side capacitor31is connected, to convert the alternating current into a direct current. The inverter circuit341further supplies the converted direct current to the power-supply-side converter circuit340. The inverter circuit341includes IGBTs in a bridge connection. Each of the IGBTs is connected in anti-parallel with a freewheel diode (flywheel diode). The inverter circuit341implements a switching operation of the IGBTs to convert a direct current, which is supplied from the power-supply-side converter circuit340, into an alternating current, which is in a rectangular waveform and at a high frequency. The inverter circuit341further supplies the converted alternating current to the power-supply-side coil30, to which the power-supply-side capacitor31is connected. The inverter circuit341is further configured to rectify an alternating current, which is supplied from the power-supply-side coil30to which the power-supply-side capacitor31is connected, to convert the alternating current into a direct current by using the freewheel diodes in a state where the IGBTs are de-activated. The inverter circuit341further supplies the converted direct current to the power-supply-side converter circuit340. The inverter circuit341is connected to the power-supply-side converter circuit340. The inverter circuit341is further connected through the power-supply-side filter circuit35to the power-supply-side coil30, to which the power-supply-side capacitor31is connected.

The power-supply-side filter circuit35includes a reactor350and a capacitor351. The power-supply-side filter circuit35has a configuration, which is substantially equivalent to a configuration of the power-supply-side filter circuit15of the first embodiment.

The power-receiving-side filter circuit38removes a predetermined frequency component included in an alternating current supplied from a rectification circuit360. The power-receiving-side filter circuit38includes a reactor380and a capacitor381, which are connected in series with each other. The power-receiving-side filter circuit38is connected between the power-receiving-side coil32, to which the power-receiving-side capacitor33is connected, and the power receiving circuit36.

A circuit, which is configured with the power-receiving-side filter circuit38, the power-receiving-side capacitor33, and the power-receiving-side coil32, has an impedance having a frequency characteristic viewed from the power receiving circuit36. The frequency characteristic includes one maximum point A and two minimum points B and C, similarly to the frequency characteristic of the circuit, which is configured with the power-supply-side filter circuit15, the power-supply-side capacitor11, and the power-supply-side coil10, viewed from the power supply circuit14, as described in the first embodiment.

The inductance of the reactor380and the capacitance of the capacitor381are set, such that a frequency of a minimum point, which is formed on the high-frequency side than a frequency of a maximum point, is greater than a frequency of the fundamental wave of an alternating current, which is in a rectangular waveform and supplied from the rectification circuit360, and is less than a frequency of a third order wave of the fundamental wave, when an electricity is transmitted from the vehicular battery B3to the commercial power source AC3. Specifically, the inductance of the reactor380and the capacitance of the capacitor381are set, such that the frequency of the minimum point, which is formed on the high-frequency side relative to the frequency of the maximum point, is greater than the frequency of the fundamental wave and less than a frequency of a second order wave of the fundamental wave. More specifically, the inductance of the reactor380and the capacitance of the capacitor381are set, such that the frequency of the minimum point, which is formed on the high-frequency side relative to the frequency of the maximum point, is 1.7 times the frequency of the fundamental wave.

The power receiving circuit36receives an alternating current supplied from the power-receiving-side coil32, to which the power-receiving-side capacitor33is connected, and rectifies the received alternating current to convert the received alternating current into a direct current. The power receiving circuit36further supplies the converted direct current to the vehicular battery B3. The power receiving circuit36is further configured to convert a direct current, which is supplied from the vehicular battery B3, into an alternating current. The power receiving circuit36is further configured to supply the converted alternating current to the power-receiving-side coil32, to which the power-receiving-side capacitor33is connected. The power receiving circuit36is equipped with the rectification circuit360and a power-receiving-side converter circuit361.

The rectification circuit360rectifies an alternating current, which is supplied from the power-receiving-side coil32, to which the power-receiving-side capacitor33is connected, through the power-receiving-side filter circuit38to convert the supplied alternating current into a direct current. The rectification circuit360further supplies the converted direct current to the power-receiving-side converter circuit361. The rectification circuit360is further configured to convert a direct current, which is supplied from the power-receiving-side converter circuit361, into an alternating current, which is in a rectangular waveform and at a high frequency. The rectification circuit360is further configured to supply the converted alternating current through the power-receiving-side filter circuit38to the power-receiving-side coil32, to which the power-receiving-side capacitor33is connected. The rectification circuit360includes IGBTs in a bridge connection. Each of the IGBTs is connected in anti-parallel with a freewheel diode (flywheel diode). The rectification circuit360rectifies an alternating current, which is supplied from the power-receiving-side coil32, to which the power-receiving-side capacitor33is connected, through the power-receiving-side filter circuit38to convert the supplied alternating current into a direct current by using the freewheel diodes in a state where the IGBTs are de-activated. The rectification circuit360further supplies the converted direct current to the power-receiving-side converter circuit361. The rectification circuit360is further configured to implement a switching operation of the IGBTs to convert a direct current, which is supplied from the power-receiving-side converter circuit361, into an alternating current, which is in a rectangular waveform and at a high frequency. The rectification circuit360is further configured to supply the converted alternating current through the power-receiving-side filter circuit38to the power-receiving-side coil32, to which the power-receiving-side capacitor33is connected. The rectification circuit360is connected to the power-receiving-side coil32, to which the power-receiving-side capacitor33is connected, though the power-receiving-side filter circuit38. The rectification circuit360is further connected to the power-receiving-side converter circuit361.

The power-receiving-side converter circuit361converts a direct current, which is supplied from the rectification circuit360, into a direct current at a different voltage. The power-receiving-side converter circuit361further supplies the converted direct current to the vehicular battery B3. The power-receiving-side converter circuit361is further configured to convert a direct current, which is supplied from the vehicular battery B3, into a direct current at a different voltage. The power-receiving-side converter circuit361is further configured to supply the converted direct current to the rectification circuit360. The power-receiving-side converter circuit361is configured with a bidirectional DC/DC converter circuit. The power-receiving-side converter circuit361is connected to both the rectification circuit360and the vehicular battery B3.

The control circuit37controls the power supply circuit34and the power receiving circuit36thereby to transmit an electricity from the commercial power source AC3to the vehicular battery B3. The control circuit37is further configured to control the power supply circuit34and the power receiving circuit36thereby to transmit an electricity from the vehicular battery B3to the commercial power source AC3. The control circuit37includes a power-supply-side control circuit370and a power-receiving-side control circuit371.

The power-supply-side control circuit370exchanges information, which is needed for control, with a power-receiving-side control circuit371via wireless communications, thereby to implement the control of the power-supply-side converter circuit340and the inverter circuit341to transmit an electricity from the commercial power source AC3to the vehicular battery B3. The power-supply-side control circuit370is further configured to implement a control of the power-supply-side converter circuit340and the inverter circuit341to transmit an electricity from the vehicular battery B3to the commercial power source AC3. The power-supply-side control circuit370is connected to both the power-supply-side converter circuit340and the inverter circuit341.

The power-receiving-side control circuit371exchanges information, which is needed for control, with a power-supply-side control circuits370via wireless communications, thereby to implement the control of the rectification circuit360and the receiving side converter circuit361to transmit an electricity from the commercial power source AC3to the vehicular battery B3. The power-receiving-side control circuit371is further configured to control the rectification circuit360and the receiving side converter circuit361thereby to transmit an electricity from the vehicular battery B3to the commercial power source AC3. The power-receiving-side control circuit371is connected to both the rectification circuit360and the power-receiving-side converter circuit361.

Subsequently, an operation of the non-contact electricity supply device of the third embodiment will be described with reference toFIG. 7. Operation to transmit an electricity from the commercial power source AC3to the vehicular battery B3is substantially equivalent to the operation of the non-contact electricity supply device1of the first embodiment. Therefore, description of the operation is omitted. In the subsequent description, an operation to transmit an electricity from the vehicular battery B3to the commercial power source AC3will be described.

The power-receiving-side converter circuit361is controlled by the power-receiving-side control circuit371to convert a direct current, which is supplied from the vehicular battery B3, into a direct current at a different voltage. The power-receiving-side converter circuit361supplies the converted direct current to the rectification circuit360. The rectification circuit360is controlled by the power-receiving-side control circuit371to convert a direct current, which is supplied from the power-receiving-side converter circuit361, into an alternating current, which is in a rectangular waveform and at a high frequency, such as tens of kHz. The rectification circuit360is further configured to supply the converted alternating current through the power-receiving-side filter circuit38to the power-receiving-side coil32, to which the power-receiving-side capacitor33is connected. The power-receiving-side filter circuit38removes a predetermined frequency component included in an alternating current supplied from the rectification circuit360. The power-receiving-side coil32, to which the power-receiving-side capacitor33is connected, is supplied with an alternating current from the rectification circuit360, thereby to generate an alternating magnetic flux.

A circuit, which is configured with the power-receiving-side filter circuit38, the power-receiving-side capacitor33, and the power-receiving-side coil32, has an impedance having a frequency characteristic. In this frequency characteristic, a frequency of a minimum point, which is formed on the high-frequency side relative to a frequency of a maximum point, is 1.7 times a frequency of a fundamental wave of an alternating current, which is in a rectangular waveform and supplied from the rectification circuit360. Therefore, a third order harmonics component of a fundamental wave of an electric current can be suppressed, and therefore, an alternating current close to a fundamental wave can be produced.

The power-supply-side coil30, to which the power-supply-side capacitor31is connected, is interlinked with the alternating magnetic flux generated by the power-receiving-side coil32thereby to implement an electromagnetic induction to produce an alternating current. The inverter circuit341is controlled by the power-supply-side control circuit370to rectify an alternating current, which is supplied from the power-supply-side coil30to which the power-supply-side capacitor31is connected, to convert the alternating current into a direct current. The inverter circuit341further supplies the converted direct current to the power-supply-side converter circuit340. The power-supply-side converter circuit340is controlled by the power-supply-side control circuit370to convert a direct current, which is supplied from the inverter circuit341, into a direct current at a different voltage. The power-supply-side converter circuit340further supplies the converted direct current to the commercial power source AC3. In such a way, electricity can be transmitted from the vehicular battery B3to the commercial power source AC1in the non-contact configuration.

Subsequently, an operation effect of the third embodiment will be described.

The non-contact electricity supply device3according to the third embodiment has a non-contact configuration to transmit an electricity from the commercial power source AC3to the vehicular battery B3thereby to charge the vehicular battery B3. The non-contact configuration of the non-contact electricity supply device3further enables to transmit an electricity from the vehicular battery B3to the commercial power source AC3thereby to supply an electric power to the commercial power source AC3. In both cases, an operation effect, which is substantially equivalent to that of the non-contact electricity supply device1of the first embodiment, can be produced.

In the third embodiment, the exemplified power-supply-side filter circuit is configured with one pair of the reactor and the capacitor, which are connected in series with each other. The disclosure is not limited to the example of the third embodiment. The power-supply-side filter circuit may be configured with two pairs of the reactors and capacitors, which are connected in series, similarly to the non-contact electricity supply device2of the second embodiment.

According to the present disclosure, the non-contact electricity supply device includes the power-supply-side coil, the power-supply-side capacitor, the power-supply-side filter circuit, and the power-receiving-side coil. The power-supply-side coil is configured to be supplied with an alternating current from the AC power source to produce a magnetic flux. The power-supply-side capacitor is connected in parallel with the power-supply-side coil to form, with the power-supply-side coil, the resonant circuit. The power-supply-side filter circuit includes the reactor and the capacitor, which are connected in series, the power-supply-side filter circuit being connected between the AC power source and the power-supply-side coil, to which the power-supply-side capacitor is connected. The power-receiving-side coil is configured to be interlinked with a magnetic flux produced by the power-supply-side coil to produce an alternating current. The capacitance of the capacitor and the inductance of the reactor of the power-supply-side filter circuit, the capacitance of the power-supply-side capacitor, and the inductance of the power-supply-side coil are set, such that the power-supply-side filter circuit, the power-supply-side capacitor, and the power-supply-side coil form the circuit having the impedance having the frequency characteristic, wherein the frequency of the minimum point, which is formed on the high-frequency side relative to the maximum point, is greater than the frequency of the fundamental wave of an alternating current supplied from the AC power source and is less than the frequency of the third order wave of the fundamental wave.

The present configuration enables to increase an impedance to the third order harmonics component of the fundamental wave. Therefore, it is possible to suppress increase in an electric current of the third order harmonics component, which has a largest amplitude among odd-order harmonics components and is not effective to power supply. Thus, it is possible to reduce a loss caused by the harmonics component included in an alternating current supplied from the AC power source.