JP7018467B2 - Power transmission device and power receiving device - Google Patents

Description

The present invention relates to a power transmission device and a power receiving device of a non-contact power feeding system that transmits power in a non-contact manner.

As a system for supplying power to a storage battery mounted on an electric vehicle or the like, there is a non-contact power supply system that transmits power in a non-contact manner (for example, Patent Document 1). In the non-contact power supply system, an inverter circuit is provided on the power transmission device side, and AC power is supplied from the inverter circuit to the power transmission coil. Then, electric power is transmitted from the power transmission coil to the power receiving coil on the vehicle side in a non-contact manner, and power is supplied from the power receiving coil to the storage battery.

In the non-contact power feeding system described in Patent Document 1, the primary coil and the direct capacitor are divided into two, and the primary partial coil and the direct partial capacitor are alternately connected in series. As a result, it is possible to suppress an increase in the voltage between the terminals of the primary coil and the series capacitor.

Japanese Unexamined Patent Publication No. 2011-176914

By the way, in the above configuration, while it is possible to suppress an increase in the voltage between terminals, there is a problem that wiring becomes complicated by dividing the primary coil. Further, when a three-phase resonance coil is adopted, it is necessary to suppress an increase in not only the terminal voltage but also the phase voltage (line voltage).

The present invention has been made in view of the above circumstances, and a main object thereof is to provide a power transmission device and a power receiving device capable of easily connecting and suppressing interphase voltage.

The first means for solving the problem is a non-contact power supply system that transmits power in a non-contact manner between a power transmission device installed outside the vehicle and a power receiving device installed in the vehicle and charges a storage battery installed in the vehicle. The power transmission device includes a power transmission unit to which a multi-phase AC current is input, the power transmission unit is provided with a power transmission side resonance unit for each phase, and each power transmission side resonance unit has a power transmission coil and the power transmission coil, respectively. It has a first capacitor connected in series to one end of the power transmission and a second power transmission connected in series to the other end of the power transmission.

The second means is a three-phase power transmission device of a non-contact power supply system that transmits power in a non-contact manner between a power transmission device installed outside the vehicle and a power receiving device installed in the vehicle and charges a storage battery installed in the vehicle. Of the currents, a U-phase power transmission side resonance portion having a U-phase power transmission coil to which the U-phase power is input, and a V-phase power transmission coil having a V-phase power transmission coil to which the V-phase power is input among the three-phase currents. Each of the power transmission side resonance parts includes a power transmission side resonance part of the phase and a W phase power transmission side resonance part having a W phase power transmission coil to which the W phase current is input among the three phase currents. It has a first capacitor connected in series to one end of the power transmission coil and a second capacitor connected in series to the other end, and one end of each of the power transmission side resonance portions is connected to a neutral point. The current of each phase is input from the other end.

The third means is a three-phase power transmission device of a non-contact power supply system that transmits power in a non-contact manner between a power transmission device provided outside the vehicle and a power receiving device installed in the vehicle and charges a storage battery provided in the vehicle. Of the currents, a U-phase power transmission side resonance portion having a U-phase power transmission coil to which the U-phase power is input, and a V-phase power transmission coil having a V-phase power transmission coil to which the V-phase power is input among the three-phase currents. Each of the power transmission side resonance parts includes a power transmission side resonance part of the phase and a W phase power transmission side resonance part having a W phase power transmission coil to which the W phase current is input among the three phase currents. It has a first capacitor connected in series to one end of the power transmission coil and a second capacitor connected in series to the other end, and the power transmission side resonance portion is delta-connected.

According to each of the above means, each transmission side resonance portion has a first capacitor connected in series to one end of the transmission coil and a second capacitor connected in series to the other end.

Therefore, in terms of circuit configuration, the power transmission coil can be regarded as a split coil in which the power transmission coil is divided into two and connected in series. Then, the voltage of the first capacitor and the voltage of the split coil on the first capacitor side are inverted. Similarly, the voltage of the second capacitor and the voltage of the split coil on the second capacitor side are inverted. Therefore, it is possible to reduce the phase voltage and the interphase voltage. Further, since the coil is not actually divided and configured, the connection can be easily performed.

The fourth means is a multi-phase power receiving device of a non-contact power feeding system that transmits power in a non-contact manner between a power transmitting device provided outside the vehicle and a power receiving device installed in the vehicle and charges a storage battery provided in the vehicle. A power receiving unit for outputting an alternating current is provided, and the power receiving unit is provided with a power receiving side resonance unit for each phase, and each power receiving side resonance unit is connected in series to a power receiving coil and one end of the power receiving coil. It has a first capacitor and a second capacitor connected in series to the other end.

The fifth means is a three-phase power receiving device of a non-contact power feeding system that transmits power in a non-contact manner between a power transmitting device provided outside the vehicle and a power receiving device installed in the vehicle and charges a storage battery provided in the vehicle. Of the currents, a U-phase power receiving side resonance portion having a U-phase power receiving coil to which a U-phase current is output, and a V having a V-phase power receiving coil to which a V-phase current is output among the three-phase currents. A phase receiving side resonance portion and a W phase power receiving side resonance portion having a W phase power receiving coil for outputting a W phase current among the three-phase currents are provided, and each of the power receiving side resonance portions is provided. It has a first capacitor connected in series to one end of the power receiving coil and a second capacitor connected in series to the other end, and one end of each of the power receiving side resonance portions is connected to a neutral point. The current of each phase is output from the other end.

The sixth means is a three-phase power receiving device of a non-contact power supply system that transmits power in a non-contact manner between a power transmitting device provided outside the vehicle and a power receiving device installed in the vehicle and charges a storage battery provided in the vehicle. Of the current, a U-phase power receiving side resonance portion having a U-phase power receiving coil that outputs a U-phase current, and a V-phase power receiving coil that has a V-phase current that outputs a V-phase current among the three-phase currents. A phase receiving side resonance portion and a W phase power receiving side resonance portion having a W phase power receiving coil for outputting a W phase current among the three-phase currents are provided, and each of the power receiving side resonance portions is provided. It has a first capacitor connected in series to one end of the power receiving coil and a second capacitor connected in series to the other end, and the power receiving side resonance portion is delta-connected.

According to each of the above means, each power receiving side resonance portion has a first capacitor connected in series to one end of the power receiving coil and a second capacitor connected in series to the other end.

Therefore, in terms of circuit configuration, the power receiving coil can be regarded as a split coil in which the power receiving coil is divided into two and connected in series. Then, the voltage of the first capacitor and the voltage of the split coil on the first capacitor side are inverted. Similarly, the voltage of the second capacitor and the voltage of the split coil on the second capacitor side are inverted. Therefore, it is possible to reduce the phase voltage and the interphase voltage. Further, since the coil is not actually divided and configured, the connection can be easily performed.

A circuit diagram showing the electrical configuration of a contactless power supply system. A perspective view showing a power transmission coil. The perspective view which shows the power receiving coil. (A) is a circuit diagram showing a resonance circuit in a comparative example, and (b) is a diagram showing an interphase voltage in the comparative example. (A) is a circuit diagram showing a resonance circuit, and (b) is a diagram showing an interphase voltage. (A) is a diagram showing a conventional correlated potential difference, (b) is a diagram showing an interphase potential difference of the present embodiment, and (c) is a diagram showing an effect of suppressing the interphase potential difference. The circuit diagram which shows the electrical structure of the non-contact power supply system of 2nd Embodiment. The plan view which shows the power transmission coil of 2nd Embodiment. (A) is a circuit diagram showing a resonance circuit in a comparative example, and (b) is a diagram showing an interphase voltage in the comparative example. (A) is a circuit diagram showing a resonance circuit of the second embodiment, and (b) is a diagram showing an interphase voltage of the second embodiment. (A) is a circuit diagram showing a resonance circuit in the third embodiment, and (b) is a diagram showing an interphase voltage in the third embodiment. (A) is a circuit diagram showing a resonance circuit in a comparative example, and (b) is a diagram showing an interphase voltage in the comparative example. The circuit diagram which shows the electric structure of the non-contact power supply system in 4th Embodiment. (A) is a circuit diagram showing a resonance circuit in the fourth embodiment, and (b) is a diagram showing an interphase voltage in the fourth embodiment. (A) is a circuit diagram showing a resonance circuit in a comparative example, and (b) is a diagram showing an interphase voltage in the comparative example. The circuit diagram which shows the resonance circuit in another example. The circuit diagram which shows the resonance circuit in another example.

(First Embodiment)
The non-contact power supply system 10 in the present embodiment includes a power transmission device 20 that non-contactly transmits power supplied from a commercial power source 11 and a power receiving device 30 that non-contactly receives power from the power transmission device 20. The power transmission device 20 is buried on the ground such as a road on which a vehicle travels (a highway or the like), a parking space for parking, or the like. The power receiving device 30 is mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and charges the vehicle-mounted battery 12 by outputting power to the vehicle-mounted battery 12 as a storage battery.

FIG. 1 shows the electrical configuration of the non-contact power feeding system 10 in the present embodiment. A commercial power supply 11 is connected to the power transmission device 20 of the contactless power supply system 10, and is configured to input AC power supplied from the commercial power supply 11 to the power transmission device 20. On the other hand, an in-vehicle battery 12 is connected to the power receiving device 30 of the non-contact power feeding system 10, and the power receiving device 30 outputs electric power to the in-vehicle battery 12 so that charging is performed. The power transmission device 20 and the power reception device 30 each have three-phase (U-phase, V-phase, W-phase) coils so that three-phase power feeding can be performed.

First, the power transmission device 20 will be described. The power transmission device 20 includes an AC-DC converter 21 connected to a commercial power supply 11, an inverter circuit 22 connected to the AC-DC converter 21, a power transmission filter circuit 23 connected to the inverter circuit 22, and a power transmission filter circuit 23. The transmission resonance circuit 24 connected to the above is provided.

The AC-DC converter 21 converts AC power supplied from the commercial power source 11 into DC power and supplies it to the inverter circuit 22. When viewed from the inverter circuit 22, the AC-DC converter corresponds to a DC power supply.

The inverter circuit 22 converts the DC power supplied from the AC-DC converter 21 into AC power having a predetermined frequency. As the inverter circuit 22, a three-phase inverter that converts three-phase AC power (three-phase current) of U-phase, V-phase, and W-phase is used.

The inverter circuit 22 is connected to the AC-DC converter 21. Specifically, the high potential side terminal of the inverter circuit 22 is connected to the positive electrode terminal of the AC-DC converter 21. On the other hand, the low potential side terminal of the inverter circuit 22 is connected to the negative electrode terminal of the AC-DC converter 21.

The inverter circuit 22 is composed of a full bridge circuit having the same number of upper and lower arms as the number of phases of each of the three phases. The current in each phase is adjusted by turning on / off the switching element provided in each arm.

More specifically, the inverter circuit 22 includes a series connection body of the upper arm switch Sp and the lower arm switch Sn as switching elements in three phases including the U phase, the V phase, and the W phase. In the present embodiment, a voltage-controlled semiconductor switching element is used as the upper arm switch Sp and the lower arm switch Sn in each phase, and specifically, an IGBT is used. In addition, MOSFET may be used. Freewheel diodes (reflux diodes) Dp and Dn are connected in antiparallel to the upper arm switch Sp and the lower arm switch Sn in each phase, respectively.

The high potential side terminal (collector) of the upper arm switch Sp of each phase is connected to the positive electrode terminal of the AC-DC converter 21. Further, the low potential side terminal (emitter) of the lower arm switch Sn of each phase is connected to the negative electrode terminal (ground) of the AC-DC converter 21. The intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase are connected to the power transmission filter circuit 23, respectively.

That is, the intermediate connection point between the upper arm switch Sp and the lower arm switch Sn in the U phase is connected to the U phase power transmission coil 26u of the power transmission resonance circuit 24 via the power transmission filter circuit 23 and the like. Similarly, the intermediate connection point between the upper arm switch Sp and the lower arm switch Sn in the V phase is connected to the power transmission coil 26v of the V phase of the power transmission resonance circuit 24 via the power transmission filter circuit 23 or the like. Similarly, the intermediate connection point between the upper arm switch Sp and the lower arm switch Sn in the W phase is connected to the W phase transmission coil 26w of the transmission resonance circuit 24 via the transmission filter circuit 23 and the like.

The power transmission filter circuit 23 is a circuit that removes power other than AC power in a predetermined frequency range from AC power input from the inverter circuit 22. A bandpass filter is used as the power transmission filter circuit 23. The power transmission filter circuit 23 includes series connectors 23a to 23c in which two reactors are connected in series for each phase. Further, the power transmission filter circuit 23 includes capacitors 23d to 23f to which one end is connected to the intermediate connection points of the series connectors 23a to 23c. The other ends of the capacitors 23d to 23f are connected at the connection point N1. That is, the other ends of the capacitors 23d to 23f are connected to each other.

The power transmission resonance circuit 24 is a circuit that outputs AC power (three-phase AC current) input from the power transmission filter circuit 23 to the power receiving device 30, and corresponds to a power transmission unit. The power transmission resonance circuit 24 has, for each phase, the first power transmission side capacitors 25u, 25v, 25w as the first power transmission side capacitors, the power transmission coils 26u, 26v, 26w, and the power transmission side as the second power transmission side capacitors. The second capacitors 27u, 27v, 27w are connected in series to the power transmission side resonance portions 20a to 20c. The transmission side resonance portions 20a to 20c are so-called star-connected. That is, one end of the power transmission side resonance portions 20a to 20c is connected to the power transmission filter circuit 23, and the other end is connected to the neutral point N2.

The first capacitors 25u, 25v, 25w on the power transmission side and the second capacitors 27u, 27v, 27w on the power transmission side have the same capacitor capacities. When mutual inductance is taken into consideration, the capacitor capacity is set as shown in the equations (1) to (5) in order to compensate for the power factor (to maximize the power factor).

In the formula, the capacitor capacity of the first capacitor 25u on the power transmission side is Csu1, and the capacitor capacity of the second capacitor 27u on the power transmission side is Csu2. Further, the capacitor capacity of the first capacitor 25v on the power transmission side is Csv1, and the capacitor capacity of the second capacitor 27v on the power transmission side is Csv2. Further, the capacitor capacity of the first capacitor 25w on the power transmission side is Csw1, and the capacitor capacity of the second capacitor 27w on the power transmission side is Csw2. Further, in the mathematical formula, the self-inductance of the power transmission coil 26u is Lu1, the self-inductance of the power transmission coil 26v is Lv1, and the self-inductance of the power transmission coil 26w is Lw1.

Further, the mutual inductance between the power transmission coil 26u and the power transmission coil 26v is set to Muv1. Further, the mutual inductance between the power transmission coil 26u and the power transmission coil 26w is set to Muw1. Further, the mutual inductance between the power transmission coil 26v and the power transmission coil 26w is set to Mvw1. The inverter drive frequency is f, and the resonant electric angular frequency is ω.

The power receiving device 30 includes a power receiving resonance circuit 31 to which power is supplied from the transmission resonance circuit 24, a power receiving filter circuit 32 connected to the power receiving resonance circuit 31, a rectifying circuit 33 connected to the power receiving filter circuit 32, and a rectifying circuit. A DC-DC converter 34 connected to 33 is provided.

The power receiving resonance circuit 31 is a circuit that inputs power from the transmission resonance circuit 24 in a non-contact manner and outputs AC power (three-phase AC current) to the power receiving filter circuit 32, and corresponds to a power receiving unit. The power receiving resonance circuit 31 has the same configuration as the power transmission resonance circuit 24, and is configured to be able to resonate with the power transmission resonance circuit 24 in a magnetic field.

That is, in each phase, the power receiving resonance circuit 31 has the power receiving side first capacitors 35u, 35v, 35w as the power receiving side first capacitors, the power receiving coils 36u, 36v, 36w, and the power receiving side second capacitors. The power receiving side second capacitors 37u, 37v, 37w and the power receiving side second capacitors 37u, 37v, 37w are connected in series to include the power receiving side resonance portions 30a to 30c. The power receiving side resonance portions 30a to 30c are so-called star-connected. That is, one end of the power receiving side resonance portions 30a to 30c is connected to the neutral point N3, and the other end is connected to the power receiving filter circuit 32. The resonance frequencies of the power receiving resonance circuit 31 and the power transmission resonance circuit 24 are set to be the same.

The capacitor capacities of the first capacitor 35u, 35v, 35w on the power receiving side and the second capacitor 37u, 37v, 37w on the power receiving side are the same. Further, as in the case of the power transmission device 20, when mutual inductance is taken into consideration, the capacitor capacity is set as shown in equations (1) to (5) in order to compensate for the power factor (to maximize the power factor). Has been done. In the mathematical formula, Csu1, Csu2, Csv1, Csv2, Csw1, Csw2, Lu1, Lv1, Lw1, Muv1, Muw1, and Mvw1 are read as corresponding to those of the power receiving device 30, respectively.

The power receiving filter circuit 32 removes power other than the AC power in a predetermined frequency range included in the AC power input from the power receiving resonance circuit 31. A bandpass filter is used as the power receiving filter circuit 32. The power receiving filter circuit 32 includes series connectors 32a to 32c in which two reactors are connected in series for each phase. Further, the power receiving filter circuit 32 includes capacitors 32d to 32f to which one end is connected to the intermediate connection points of the series connectors 32a to 32c. The other ends of the capacitors 32d to 32f are connected at the connection point N4. That is, the other ends of the capacitors 32d to 32f are connected to each other.

The rectifier circuit 33 is a circuit that full-wave rectifies AC power. In the present embodiment, a full-wave rectifier circuit composed of a diode bridge is adopted as the rectifier circuit 33, but a synchronous rectifier circuit composed of six switching elements (for example, MOSFET) may be used.

The DC-DC converter 34 transforms the DC power input from the rectifier circuit 33 and outputs it to the vehicle-mounted battery 12. The vehicle-mounted battery 12 charges the DC power input from the DC-DC converter 34.

Further, the power transmission device 20 is provided with a power transmission control unit 60 that controls the power transmission device 20, and the power reception device 30 is provided with a power reception control unit 70 that controls the power reception device 30. The power transmission control unit 60 controls the AC-DC converter 21, the inverter circuit 22, and the like. The power receiving control unit 70 controls the DC-DC converter 34 and the like. Further, the vehicle is provided with an ECU 50 (Electronic Control Unit), which gives an instruction to the power receiving control unit 70 to perform non-contact power supply while the vehicle is running to charge the in-vehicle battery 12.

According to the above configuration, when the AC power is input to the power transmission resonance circuit 24 in a situation where the relative positions of the power transmission device 20 and the power reception device 30 are in a position where the magnetic field resonance is possible, the power transmission coils 26u, 26v, 26w and the power reception coil 26u, 26v, 26w are received. The coils 36u, 36v, 36w resonate in a magnetic field. As a result, the power receiving device 30 receives a part of energy from the power transmitting device 20. That is, it receives AC power. In this embodiment, for convenience of explanation, it is assumed that the relative positions of the power transmitting device 20 and the power receiving device 30 are at positions where magnetic field resonance is possible.

Next, the mechanical configurations of the power transmission coils 26u, 26v, 26w and the power reception coils 36u, 36v, 36w will be described. FIG. 2 is a perspective view of the power transmission coil 26u, 26v, 26w and the power reception coil 36u, 36v, 36w as viewed from the upper surface side (vehicle side, power reception side), and FIG. 3 is a perspective view of the lower surface side (road side, power transmission side). It is a perspective view seen from.

As shown in FIG. 2, the power transmission coils 26u, 26v, 26w are square flat coils formed by winding windings (for example, litz wires) in a plane. At that time, the power transmission coils 26u, 26v, 26w are formed in an annular shape. The shape and number of turns of each power transmission coil 26u, 26v, 26w are the same.

These power transmission coils 26u, 26v, 26w are arranged and fixed on the ferrite core 28 as an iron core. More specifically, the ferrite core 28 is formed in the shape of a rectangular flat plate, and is arranged so that its longitudinal direction is along the extending direction of the road. Further, the ferrite core 28 is arranged so that the lateral direction is the width direction of the road and the plane is parallel to the road surface of the road. Then, on the plane of the ferrite core 28, the power transmission coils 26u, 26v, 26w are arranged along the longitudinal direction. At that time, the power transmission coils 26u, 26v, 26w are arranged so as to be on the vehicle side (upper side) of the ferrite core 28.

The power transmission coils 26u, 26v, and 26w are arranged on the ferrite core 28 so as to be displaced from each other in the longitudinal direction. More specifically, the region surrounded by the power transmission coils 26u, 26v, 26w is arranged so as to overlap each other with respect to the region surrounded by the other power transmission coils 26u, 26v, 26w. At that time, the power transmission coils 26u, 26v, 26w are arranged so as to be displaced at equal intervals in the longitudinal direction. More specifically, they are arranged with an electrical angle offset by 120 °. In the present embodiment, the power transmission coil 26u is arranged in the center in the longitudinal direction, and the power transmission coils 26v and 26w are arranged on both sides in the longitudinal direction of the power transmission coil 26u.

Next, the power receiving coils 36u, 36v, 36w will be described. The power receiving coils 36u, 36v, 36w are configured in substantially the same manner as the power transmission coils 26u, 26v, 26w.

That is, as shown in FIG. 3, the power receiving coils 36u, 36v, 36w are square flat coils formed by winding windings (for example, litz wires) in a plane. At that time, the power receiving coils 36u, 36v, 36w are formed in an annular shape. The shape and the number of turns of each of the power receiving coils 36u, 36v, 36w are the same.

These power receiving coils 36u, 36v, 36w are arranged and fixed on the ferrite core 38 as an iron core. More specifically, the ferrite core 38 is formed in the shape of a rectangular flat plate, and is arranged so that its longitudinal direction is along the traveling direction of the vehicle. Further, the ferrite core 38 is arranged so that the lateral direction of the ferrite core 38 is the width direction of the vehicle and the plane surface is parallel to the bottom surface of the vehicle. That is, the plane of the ferrite core 38 is arranged so as to face the road surface of the road. Then, on the ferrite core 38, the power receiving coils 36u, 36v, 36w are arranged along the traveling direction (longitudinal direction). At that time, the power receiving coils 36u, 36v, 36w are arranged so as to be on the road side (lower side) of the ferrite core 38.

The power receiving coils 36u, 36v, 36w are arranged on the ferrite core 38 so as to be displaced from each other in the longitudinal direction. More specifically, the region surrounded by the power receiving coils 36u, 36v, 36w is arranged so as to overlap each other with respect to the region surrounded by the other power receiving coils 36u, 36v, 36w. At that time, the power receiving coils 36u, 36v, 36w are arranged so as to be displaced at equal intervals in the longitudinal direction. More specifically, they are arranged with an electrical angle offset by 120 °. In this embodiment, the power receiving coil 36u is arranged in the center in the longitudinal direction, and the power receiving coils 36v and 36w are arranged on both sides in the longitudinal direction of the power receiving coil 36u.

By the way, in the power transmission resonance circuit 24 and the power reception resonance circuit 31, when the voltage (phase voltage) between the terminals of the coil or the capacitor becomes high, it is necessary to take measures against high voltage. In particular, if a coil and a capacitor are connected in series, the voltage between terminals tends to rise, which is a problem. Further, in the three-phase power supply, when the interphase voltage becomes high, partial discharge may occur and dielectric breakdown may occur, so it is necessary to take measures such as thickening the insulating layer or increasing the interphase distance.

Here, a comparative example (conventional example) is shown in FIG. 4, and the terminal voltage and the phase voltage in the circuit configuration shown in FIG. 4 will be described. In the circuit configuration of FIG. 4, the resonant circuit consists of coils Lu, Lv, Lw and capacitors Cu, Cv, Cw connected in series to the coils Lu, Lv, Lw, one end of which is connected to the neutral point N0. ing. The same applies to both the power transmission side and the power reception side.

In this case, the magnitude of the phase voltage (U-phase voltage, V-phase voltage, W-phase voltage, all vector values) at the connection points Na, Nb, Nc between the coil Lu, Lv, Lw and the capacitors Cu, Cv, Cw. Is the same value for each phase. The phase is shifted by 120 degrees. This phase voltage corresponds to the voltage between terminals. The magnitude of the phase-to-phase voltage (U-V phase-to-phase voltage, V-W-phase voltage, WW-U-phase voltage, all of which are vector values) is shown in the voltage vector diagram of the phase voltage and the phase-to-phase voltage (FIG. 4 (FIG. 4). b) See), √3 times the magnitude of the phase voltage.

Next, the terminal voltage (phase voltage) and the phase voltage in the circuit configuration of the present embodiment will be described with reference to FIG. FIG. 5 is a diagram showing a circuit configuration of the power transmission side resonance portions 20a to 20c.

In the following description, in the circuit configuration, the connection points between the transmission side first capacitors 25u, 25v, 25w and the transmission coils 26u, 26v, 26w are referred to as connection points U1, V1, W1, respectively. Further, the connection points between the second capacitors 27u, 27v, 27w on the power transmission side and the power transmission coils 26u, 26v, 26w are referred to as connection points U2, V2, W2, respectively.

Further, the voltage (vector value) of the connection point U1 with respect to the neutral point N2 is indicated by Vu1, the voltage (vector value) of the connection point V1 with respect to the neutral point N2 is indicated by Vv1, and the connection point W1 with respect to the neutral point N2 is indicated. The voltage (vector value) of is shown as Vw1.

Since the circuit configurations of the power transmission side and the power reception side are the same, only the power transmission side will be described, and the description of the power reception side will be omitted. When read as the power receiving side, the power transmitting side first capacitors 25u, 25v, 25w correspond to the power receiving side first capacitors 35u, 35v, 35w, and the power transmission coils 26u, 26v, 26w correspond to the power receiving coils 36u, 36v, 36w. The second capacitors 27u, 27v, 27w on the power transmission side correspond to the second capacitors 37u, 37v, 37w on the power reception side. Further, the neutral point N2 corresponds to the neutral point N3. The transmission side resonance portions 20a to 20c correspond to the power reception side resonance portions 30a to 30c.

In the power transmission side resonance portions 20a to 20c, the power transmission coil 26u, 26v, 26w is arranged between the power transmission side first capacitor 25u, 25v, 25w and the power transmission side second capacitor 27u, 27v, 27w, and the power transmission coil 26u, It is provided symmetrically around 26v and 26w. The first capacitors 25u, 25v, 25w on the power transmission side and the second capacitors 27u, 27v, 27w on the power transmission side have the same capacitor capacities.

Therefore, although the first capacitors 25u, 25v, 25w on the power transmission side are not actually divided, the power transmission coils 26u, 26v, 26w are 1/2 of the power transmission coils 26u, 26v, 26w in terms of circuit configuration. It can be considered that the divided coils L1 and L2 divided into the above are connected in series.

That is, in the power transmission side resonance portions 20a to 20c, the power transmission side first capacitors 25u, 25v, 25w, the split coil L1, the split coil L2, and the power transmission side second capacitors 27u, 27v, 27w are connected in series in this order. It can be considered connected. Further, one end of the power transmission side resonance portions 20a to 20c (one end on the power transmission side first capacitors 25u, 25v, 25w side) is connected to the neutral point N2. Then, the potential at the neutral point N2 becomes 0 V (reference potential).

The voltage of the first capacitor 25u, 25v, 25w on the power transmission side and the voltage (vector value) of the split coil L1 are inverted (out of phase by 180 degrees). Similarly, the voltage of the second power transmission side capacitors 27u, 27v, 27w and the voltage (vector value) of the split coil L2 are inverted (180 degrees out of phase). Further, at the time of resonance, the amplitude of the voltage is also the same. Therefore, the potential at the intermediate point H0 of the split coils L1 and L2 is also 0 V (reference potential), and the voltage of the split coil L1 and the voltage of the split coil L2 are similarly inverted (180 degree out of phase). You can see that.

Therefore, the voltages Vu2, Vv2, Vw2 of the connection points U1, V1, W1 with respect to the intermediate point H0 (reference potential) and the voltages Vu1, Vv1, Vw1 of the connection points U1, V1, W1 with respect to the neutral point N2 (reference potential). Have a relationship as shown in the equations (6) to (10). The voltage (vector value) of the connection point U1 with respect to the intermediate point H0 is indicated by Vu2, the voltage (vector value) of the connection point V1 with respect to the intermediate point H0 is indicated by Vv2, and the voltage of the connection point W1 with respect to the intermediate point H0 (the voltage of the connection point W1 with respect to the intermediate point H0). Vector value) is shown as Vw2.

-Vu1 = Vu2 ... (6)
-Vv1 = Vv2 ... (7)
-Vw1 = Vw2 ... (8)
-Vu1-Vv1-Vw1 = 0 ... (9)
Vu2 + Vv2 + Vw2 = 0 ... (10)
Therefore, the phase voltage (vector value) Pu of the U phase, which is the voltage of the connection point U2 with respect to the connection point U1, the phase voltage (vector value) Pv of the V phase, which is the voltage of the connection point V2 with respect to the connection point V1, and the connection point W1. The phase voltage (vector value) Pw of the W phase, which is the voltage of the connection point W2, is as shown in Equations (11) to (16) and FIG. 5 (b). The voltage vector of the connection point U2 with respect to the intermediate point H0 is indicated by Vu3, the voltage vector of the connection point V2 with respect to the intermediate point H0 is indicated by Vv3, and the voltage vector of the connection point W2 with respect to the intermediate point H0 is indicated by Vw3.

Pu = Vu3-Vu2 ... (11)
Pv = Vv3-Vv2 ... (12)
Pw = Vw3-Vw2 ... (13)
Vu3 = -Vu2 ... (14)
Vv3 = -Vv2 ... (15)
Vw3 = -Vw2 ... (16)
Therefore, as shown in Equations (11) to (16) and FIG. 5 (b), the magnitudes of the phase voltages Pu, Pv, and Pw are the same. Then, based on the voltage vector diagrams shown in the equations (11) to (16) and FIG. 5 (b), the interphase voltage Puv1 between the connection point U1 and the connection point V1 is shown in the equations (17) and 5 (b). Will be shown. The interphase voltage Puv2 between the connection point U2- and the connection point V2 is as shown in the equation (18) and FIG. 5 (b). The interphase voltage Pvw1 between the connection point V1 and the connection point W1 is as shown in Equation (19) and FIG. 5 (b). The interphase voltage Pvw2 between the connection point V2- and the connection point W2 is as shown in the equation (20) and FIG. 5 (b). The interphase voltage Pwoo1 between the connection point W1 and the connection point U1 is as shown in the equation (21) and FIG. 5 (b). The interphase voltage Pwoo2 between the connection point W2- and the connection point U2 is as shown in the equation (22) and FIG. 5 (b).

Puv1 = Vu2-Vv2 ... (17)
Puv2 = Vu3-Vv3 ... (18)
Pvw1 = Vv2-Vw2 ... (19)
Pvw2 = Vv3-Vw3 ... (20)
Pwoo1 = Vw2-Vu2 ... (21)
Pw2 = Vw3-Vu3 ... (22)
Therefore, as shown in Equations (17) to (22) and FIG. 5 (b), the magnitudes of the interphase voltages Puv1, Puv2, Pvw1, Pvw2, Pwoo1, and Pwoo2 are the same. Further, the magnitude of the interphase voltage Puv1, Puv2, Pvw1, Pvw2, Pwoo1, Pwoo2 is 1/2 × √3 times the magnitude of the phase voltage Pu, Pv, Pw. For example, the magnitude of the phase voltage Puv1 is 1/2 × √3 times the magnitude of the phase voltage Pu, as shown in the equation (23). That is, in theory, the interphase voltage can be halved.

｜ Puv1 ｜ ＝ ｜ Pu ｜ × 1/2 × √3 ・ ・ ・ (23)
Next, the operation and effect of the circuit configuration of this embodiment will be described. FIG. 6A shows the phase-to-phase potential difference (phase-to-phase voltage) in the circuit configuration of the comparative example (see FIG. 4), and FIG. 6 (b) shows the phase-to-phase potential difference (phase-to-phase) in the circuit configuration of the present embodiment (see FIG. 1). Voltage) is shown. Further, FIG. 6C shows a comparison between the maximum phase-to-phase potential difference (maximum phase-to-phase voltage) in the circuit configuration of the comparative example and the maximum-phase potential difference (maximum-phase voltage) in the circuit configuration of the present embodiment.

As shown in FIG. 6, by adopting the circuit configuration of the present embodiment, the interphase voltage can be reduced on both the power transmission side and the power reception side as compared with the circuit configuration of the comparative example. Also, as shown in FIG. 6 (c), the maximum interphase voltage can be reduced by 46 percent. As a result, the thickness of the insulating layer of the power transmission coils 26u, 26v, 26w can be reduced. Similarly, the thickness of the insulating layer of the power receiving coils 36u, 36v, 36w can be reduced. It should be noted that the variation in the interphase voltage is due to the mutual inductance due to the difference in distance.

Further, since the power transmission coils 26u, 26v, 26w and the power reception coils 36u, 36v, 36w are not actually divided and configured, the wiring is easy.

(Second Embodiment)
In the first embodiment, the configuration may be changed as follows. Hereinafter, in the second embodiment, differences from the configurations described in each of the above embodiments will be mainly described. Further, in the second embodiment, the basic configuration of the non-contact power feeding system 10 will be described by taking the one of the first embodiment as an example.

As shown in FIG. 7, the power transmission device 120 and the power reception device 130 in the second embodiment have two-phase (U-phase, V-phase) coils, respectively, so as to enable two-phase power supply.

First, the power transmission device 120 will be described. The inverter circuit 22 of the second embodiment is configured in the same manner as in the first embodiment, and converts a direct current into two-phase alternating current (two-phase alternating current) of U phase and V phase. The power transmission resonance circuit 124 of the second embodiment is a circuit (power transmission unit) that outputs AC power input from the power transmission filter circuit 23 to the power receiving device 130. The power transmission resonance circuit 124 includes a power transmission side first capacitor 125u, 125v as a power transmission side first capacitor, a power transmission coil 126u, 126v, and a power transmission side second capacitor 127u as a power transmission side second capacitor for each phase. , 127v and the transmission side resonance portions 120a and 120b are connected in series.

One end of the power transmission side resonance portion 120a of the U phase is connected to an intermediate connection point (connection point between the upper arm switch Sp and the lower arm switch Sn) in the U phase of the inverter circuit 22 via the power transmission filter circuit 23. The other end is connected to the connection point N12. One end of the V-phase power transmission side resonance portion 120b is connected to the intermediate connection point in the V phase of the inverter circuit 22 via the power transmission filter circuit 23, and the other end is connected to the connection point N12. The connection point N12 is connected to an intermediate connection point other than the U phase and the V phase in the inverter circuit 22 without going through the power transmission filter circuit 23.

The capacitor capacities of the first power transmission side capacitors 125u and 125v and the second power transmission side capacitors 127u and 127v are set to be the same. When mutual inductance is taken into consideration, the capacitor capacity is set as shown in the equations (31) to (33) in order to compensate for the power factor (to maximize the power factor).

In the formula, the capacitor capacity of the first capacitor 125u on the power transmission side is Csu11, and the capacitor capacity of the second capacitor 127u on the power transmission side is Csu12. Further, the capacitor capacity of the first capacitor 125v on the power transmission side is Csv11, and the capacitor capacity of the second capacitor 127v on the power transmission side is Csv12. Further, in the mathematical formula, the self-inductance of the power transmission coil 126u is set to Lu11, and the self-inductance of the power transmission coil 126v is set to Lv11. Further, the inverter drive frequency is set to f, and the resonant electric angular frequency is set to ω.

The power receiving device 130 of the second embodiment will be described. The power receiving resonance circuit 131 of the second embodiment has the same configuration as the power transmission resonance circuit 124, and is configured to be able to resonate with the power transmission resonance circuit 124 in a magnetic field.

That is, in each phase, the power receiving resonance circuit 131 has a power receiving side first capacitor 135u, 135v as a power receiving side first capacitor, a power receiving coil 136u, 136v, and a power receiving side second capacitor as a power receiving side second capacitor. The capacitors 137u and 137v are connected in series to the receiving side resonance portions 130a and 130b. One end of the power receiving side resonance portions 130a and 130b is connected to the connection point N13, and the other end is connected to the power receiving filter circuit 32. Further, the connection point N13 is connected to the rectifier circuit 33 without going through the power receiving filter circuit 32. The resonance frequencies of the power receiving resonance circuit 131 and the power transmission resonance circuit 124 are set to be the same.

The capacitor capacities of the first capacitors 135u and 135v on the power receiving side and the second capacitors 137u and 137v on the power receiving side are set to be the same. Further, as in the case of the power transmission device 120, the capacitor capacity is set as shown in equations (31) to (33) in order to compensate for the power factor (to maximize the power factor) when mutual inductance is taken into consideration. Has been done. In the mathematical formula, Csu11, Csu12, Csv11, Csv12, Lu11, and Lv11 are read as corresponding to those of the power receiving device 130, respectively.

According to the above configuration, when AC power is input to the transmission resonance circuit 124 in a situation where the relative positions of the transmission device 120 and the power reception device 130 are in a position where magnetic resonance is possible, the transmission coils 126u and 126v and the power reception coil 136u , 136v and magnetically resonate. As a result, the power receiving device 130 receives a part of energy from the power transmitting device 120. That is, it receives AC power. In this embodiment, for convenience of explanation, it is assumed that the relative positions of the power transmitting device 120 and the power receiving device 130 are in positions where magnetic field resonance is possible.

Next, the mechanical configurations of the power transmission coils 126u and 126v and the power reception coils 136u and 136v will be described. FIG. 8 is a plan view of the power transmission coils 126u and 126v as viewed from the upper surface side (vehicle side, power receiving side). Since the mechanical configurations of the power receiving coils 136u and 136v are the same as those of the power transmission coils 126u and 126v, the drawings and detailed description thereof will be omitted.

As shown in FIG. 8, the power transmission coils 126u and 126v are square flat coils formed by winding windings (for example, litz wires) in a plane. At that time, the power transmission coils 126u and 126v are formed in an annular shape. The shape and number of turns of each power transmission coil 126u and 126v are the same.

These power transmission coils 126u and 126v are arranged and fixed on the ferrite core 128 as an iron core. The power transmission coils 126u and 126v are arranged along the longitudinal direction on the plane of the ferrite core 128. At that time, the power transmission coils 126u and 126v are arranged so as to be on the vehicle side (upper side) of the ferrite core 128.

The power transmission coils 126u and 126v are arranged on the ferrite core 128 so as to be displaced from each other in the longitudinal direction. More specifically, the region surrounded by the power transmission coils 126u, 126v is arranged so as to overlap each other with respect to the region surrounded by the other power transmission coils 126u, 126v. At that time, the power transmission coils 126u and 126v are arranged so as to deviate from each other by a predetermined angle in the longitudinal direction. More specifically, they are arranged with an electrical angle offset by 90 °.

By the way, in the power transmission resonance circuit 124 and the power reception resonance circuit 131, it is desired to reduce the terminal voltage and the phase voltage as in the first embodiment. Here, a comparative example is shown in FIG. 9, and the terminal voltage and the phase voltage in the circuit configuration of FIG. 9 will be described. In the circuit configuration of FIG. 9, the resonant circuit consists of coils Lu, Lv and capacitors Cu, Cv connected in series with the coils Lu, Lv, and one end thereof is connected to the connection point N10. The same applies to both the power transmission side and the power reception side.

In this case, the magnitude of the phase voltage (U-phase voltage, V-phase voltage, both vector values) at the connection points Na and Nb between the coils Lu and Lv and the capacitors Cu and Cv is the same value for each phase. In the case of two-phase feeding, the phase is shifted by 90 degrees. This phase voltage corresponds to the voltage between terminals. The magnitude of the phase voltage (UV-phase voltage, vector value) is √2 times the magnitude of the phase voltage as shown in the voltage vector diagram of the phase voltage and the phase voltage (see FIG. 9B). Will be.

Next, the terminal voltage (phase voltage) and the phase voltage in the circuit configuration of the second embodiment will be described with reference to FIG. FIG. 10A is a diagram showing a circuit configuration of the power transmission side resonance portions 120a and 120b.

In the second embodiment, in the circuit configuration, the connection points between the transmission side first capacitors 125u and 125v and the transmission coils 126u and 126v are referred to as connection points U1 and V1, respectively. Further, the connection points between the second power transmission side capacitors 127u and 127v and the power transmission coils 126u and 126v are referred to as connection points U2 and V2, respectively. Further, the voltage (vector value) of the connection point U1 with respect to the connection point N12 is indicated by Vu11, and the voltage (vector value) of the connection point V1 with respect to the connection point N12 is indicated by Vv11.

Since the circuit configurations of the power transmission side and the power reception side are the same, only the power transmission side will be described, and the description of the power reception side will be omitted. When read as the power receiving side, the power transmission side first capacitors 125u and 125v correspond to the power receiving side first capacitors 135u and 135v, and the power transmission coils 126u and 126v correspond to the power receiving coils 136u and 136v, and the power transmission side second capacitors 127u. , 127v correspond to the second capacitors 137u and 137v on the power receiving side. Further, the connection point N12 corresponds to the connection point N13. The power transmission side resonance portions 120a and 120b correspond to the power reception side resonance portions 130a and 130b.

In the power transmission side resonance portions 120a and 120b, the power transmission coils 126u and 126v are arranged between the power transmission side first capacitors 125u and 125v and the power transmission side second capacitors 127u and 127v, and are symmetrical about the power transmission coils 126u and 126v. It is provided. The capacitor capacities of the first power transmission side capacitors 125u and 125v and the second power transmission side capacitors 127u and 127v are set to be the same.

Therefore, although the first capacitors 125u and 125v on the power transmission side are not actually divided, in terms of circuit configuration, the power transmission coils 126u and 126v are divided coils L11 in which the power transmission coils 126u and 126v are divided into 1/2. , L12 can be regarded as connected in series.

That is, in the power transmission side resonance portions 120a and 120b, the power transmission side first capacitors 125u and 125v, the split coil L11, the split coil L12, and the power transmission side second capacitors 127u and 127v are connected in series in this order. Can be regarded as. Further, one end of the transmission side resonance portions 120a and 120b (one end on the transmission side first capacitor 125u and 125v side) is connected to the connection point N12.

The voltage of the first capacitors 125u and 125v on the power transmission side and the voltage (vector value) of the split coil L11 are inverted (out of phase by 180 degrees). Similarly, the voltage of the second power transmission side capacitors 127u and 127v and the voltage (vector value) of the split coil L12 are inverted (180 degrees out of phase). Further, at the time of resonance, the amplitude of the voltage is also the same. Therefore, the potential of the intermediate point H10 of the divided coils L11 and L12 becomes the same potential as the connection point N12, and the voltage of the divided coil L11 and the voltage of the divided coil L12 are also inverted (180 degree phase is inverted). It turns out that it shifts).

Therefore, the voltages Vu12 and Vv12 of the connection points U1 and V1 with respect to the intermediate point H10 (reference potential) and the voltages Vu11 and Vv11 of the connection points U1 and V1 with respect to the connection point N12 (reference potential) are mathematical formulas (34) to (35). There is a relationship like. The voltage (vector value) of the connection point U1 with respect to the intermediate point H10 is indicated by Vu12, and the voltage (vector value) of the connection point V1 with respect to the intermediate point H10 is indicated by Vv12.

-Vu11 = Vu12 ... (34)
-Vv11 = Vv12 ... (35)
Therefore, the phase voltage (vector value) Pv of the U phase, which is the voltage of the connection point U2 with respect to the connection point U1, and the phase voltage (vector value) Pv of the V phase, which is the voltage of the connection point V2 with respect to the connection point V1, are given by the equation (36). )-(39) and FIG. 10 (b). The voltage vector of the connection point U2 with respect to the intermediate point H10 is indicated by Vu13, and the voltage vector of the connection point V2 with respect to the intermediate point H10 is indicated by Vv13.

Pu = Vu13-Vu12 ... (36)
Pv = Vv13-Vv12 ... (37)
Vu13 = -Vu12 ... (38)
Vv13 = -Vv12 ... (39)
Therefore, as shown in Equations (36) to (39) and FIG. 10 (b), the magnitudes of the phase voltages Pu and Pv are the same. Then, based on the voltage vector diagrams shown in the equations (36) to (39) and FIG. 10 (b), the interphase voltage Puv 11 between the connection point U1 and the connection point V1 is shown in the equations (40) and 10 (b). Will be shown. The interphase voltage Puv12 between the connection point U2- and the connection point V2 is as shown in Equation (41) and FIG. 10 (b).

Puv11 = Vu12-Vv12 ... (40)
Puv12 = Vu13-Vv13 ... (41)
Therefore, as shown in Equations (36) to (41) and FIG. 10 (b), the magnitudes of the interphase voltages Puv11 and Puv12 are the same. Further, the magnitude of the interphase voltages Puv11 and Puv12 is 1/2 × √2 times the magnitude of the phase voltages Pu and Pv. For example, the magnitude of the phase voltage Puv11 is 1/2 × √2 times the magnitude of the phase voltage Pu, as shown in the equation (42). That is, in theory, the interphase voltage can be halved.

｜ Puv1 ｜ ＝ ｜ Pu ｜ × 1/2 × √2 ・ ・ ・ (42)
Next, the operation and effect of the circuit configuration of the second embodiment will be described. By adopting the circuit configuration of the second embodiment, the interphase voltage can be reduced on both the power transmission side and the power reception side as compared with the circuit configuration of FIG. Specifically, the maximum interphase voltage can be reduced by 50 percent. As a result, the thickness of the insulating layer of the power transmission coils 126u and 126v can be reduced. Similarly, the thickness of the insulating layer of the power receiving coils 136u and 136v can be reduced. Further, since the power transmission coils 126u and 126v and the power reception coils 136u and 136v are not actually divided and configured, the wiring is easy.

(Third Embodiment)
In the first embodiment, the configuration may be changed as follows. Hereinafter, in the third embodiment, differences from the configurations described in each of the above embodiments will be mainly described. Further, in the third embodiment, the basic configuration of the non-contact power feeding system 10 will be described by taking the one of the first embodiment as an example.

In the first embodiment, the power transmission side resonance portions 20a to 20c (and the power reception side resonance portions 30a to 30c) are so-called star-connected, but as shown in FIG. 11A, delta connection may be performed. .. That is, one end of the power transmission side resonance portion 20a is connected to one end of the power transmission side resonance portion 20b, and the other end is connected to one end of the power transmission side resonance portion 20c. Then, the other end of the power transmission side resonance portion 20b and the other end of the power transmission side resonance portion 20c are connected. Further, one end of each transmission side resonance portion 20a to 20c is connected to the inverter circuit 22 via the power transmission filter circuit 23. More specifically, one end of each transmission side resonance portion 20a to 20c is connected to an intermediate connection point in each phase of the inverter circuit 22. The same applies to the power receiving device 30.

Even when the delta connection is performed, it is desired that the power transmission resonance circuit 24 and the power reception resonance circuit 31 reduce the interphase voltage and the like as in the first embodiment. Here, a comparative example is shown in FIG. 12 (a), and the terminal voltage and the phase voltage in the circuit configuration with the delta connection of FIG. 12 (a) will be described. In the circuit configuration of FIG. 12A, the resonant circuit consists of coils Lu, Lv, Lw and capacitors Cu, Cv, Cw connected in series to the coils Lu, Lv, Lw, and these are delta-connected. There is. The same applies to both the power transmission side and the power reception side.

In this case, the magnitude of the phase voltage (U-phase voltage, V-phase voltage, W-phase voltage, all vector values) at the connection points Na, Nb, Nc between the coil Lu, Lv, Lw and the capacitors Cu, Cv, Cw. Is the same value for each phase. The phase is shifted by 120 degrees. This phase voltage corresponds to the voltage between terminals. The magnitude of the phase-to-phase voltage (U-V phase-to-phase voltage, V-W-phase voltage, WW-to-phase voltage, all of which are vector values) is shown in the voltage vector diagram of the phase voltage and the phase-to-phase voltage (FIG. 12 (FIG. 12). b) See), √3 times the magnitude of the phase voltage.

Next, the terminal voltage (phase voltage) and the phase voltage in the circuit configuration of the present embodiment will be described with reference to FIG.

In the third embodiment, in the circuit configuration, the connection points between the transmission side first capacitors 25u, 25v, 25w and the transmission coils 26u, 26v, 26w are referred to as connection points U1, V1, W1, respectively. Further, the connection points between the second capacitors 27u, 27v, 27w on the power transmission side and the power transmission coils 26u, 26v, 26w are referred to as connection points U2, V2, W2, respectively.

Further, the voltage (vector value) of the connection point U1 with respect to the connection point N21 between the transmission side resonance portion 20b and the transmission side resonance portion 20c is referred to as Vu1. The voltage (vector value) of the connection point V1 with respect to the connection point N22 between the electric side resonance portion 20a and the power transmission side resonance portion 20b is referred to as Vv1. The voltage (vector value) of the connection point W1 with respect to the connection point N23 between the electric side resonance portion 20a and the power transmission side resonance portion 20c is shown as Vw1.

Further, the voltage (vector value) of the connection point U1 with respect to the intermediate point H0 is indicated by Vu2, the voltage (vector value) of the connection point V1 with respect to the intermediate point H0 is indicated by Vv2, and the voltage of the connection point W1 with respect to the intermediate point H0 (the voltage of the connection point W1 with respect to the intermediate point H0). Vector value) is shown as Vw2. Further, the voltage vector of the connection point U2 with respect to the intermediate point H0 is indicated by Vu3, the voltage vector of the connection point V2 with respect to the intermediate point H0 is indicated by Vv3, and the voltage vector of the connection point W2 with respect to the intermediate point H0 is indicated by Vw3.

For the same reason as in the first embodiment, the phase voltage (vector value) Pu of the U phase, which is the voltage of the connection point U2 with respect to the connection point U1, and the phase voltage (vector) of the V phase, which is the voltage of the connection point V2 with respect to the connection point V1. (Value) Pv, the phase voltage (vector value) Pw of the W phase, which is the voltage of the connection point W2 with respect to the connection point W1, are as shown in equations (11) to (16) and FIG. 11 (b).

Pu = Vu3-Vu2 ... (11)
Pv = Vv3-Vv2 ... (12)
Pw = Vw3-Vw2 ... (13)
Vu3 = -Vu2 ... (14)
Vv3 = -Vv2 ... (15)
Vw3 = -Vw2 ... (16)
Then, for the same reason as in the first embodiment, the phase voltage Puv1 between the connection points U1-connection point V1, the phase voltage Puv2 between the connection points U2-connection point V2, and the phase voltage Pvw1 between the connection points V1-connection point W1. , Connection point V2-Phase voltage Pvw2 between connection points W2, Connection point W1-Phase voltage Pw1 between connection points U1, and Connection point W2-Phase voltage Pw2 between connection points U2 are mathematical formulas (17) to (22), respectively. ) And FIG. 11 (b).

Puv1 = Vu2-Vv2 ... (17)
Puv2 = Vu3-Vv3 ... (18)
Pvw1 = Vv2-Vw2 ... (19)
Pvw2 = Vv3-Vw3 ... (20)
Pwoo1 = Vw2-Vu2 ... (21)
Pw2 = Vw3-Vu3 ... (22)
Then, for the same reason as in the first embodiment, the magnitude of the interphase voltage Puv1, Puv2, Pvw1, Pvw2, Pwoo1, Pwoo2 is 1/2 × √3 times the magnitude of the phase voltage Pu, Pv, Pw. .. For example, the magnitude of the phase voltage Puv1 is 1/2 × √3 times the magnitude of the phase voltage Pu, as shown in the equation (23). That is, in theory, the interphase voltage can be halved.

｜ Puv1 ｜ ＝ ｜ Pu ｜ × 1/2 × √3 ・ ・ ・ (23)
Since the circuit configurations of the power transmission side and the power reception side are the same, only the power transmission side will be described, and the description of the power reception side will be omitted.

Therefore, in the third embodiment as well as in the first embodiment, the interphase voltage can be reduced on both the power transmission side and the power reception side as compared with the circuit configuration of the comparative example shown in FIG. As a result, the thickness of the insulating layer of the power transmission coils 26u, 26v, 26w can be reduced. Similarly, the thickness of the insulating layer of the power receiving coils 36u, 36v, 36w can be reduced. Further, since the power transmission coils 26u, 26v, 26w and the power reception coils 36u, 36v, 36w are not actually divided and configured, the wiring is easy.

(Fourth Embodiment)
In the first embodiment, the configuration may be changed as follows. Hereinafter, in the fourth embodiment, differences from the configurations described in each of the above embodiments will be mainly described. Further, in the fourth embodiment, the basic configuration of the non-contact power feeding system 10 will be described by taking the one of the first embodiment as an example.

In the first embodiment, the power transmission side resonance portions 20a to 20c (and the power reception side resonance portions 30a to 30c) are so-called star-connected, but as shown in FIGS. 13 and 14, V-connection may be performed. .. That is, the capacitor C100 may be arranged instead of the transmission side resonance portion 20c. The same applies to the power receiving device 30.

Even when the V connection is performed, it is desired that the power transmission resonance circuit 24 and the power reception resonance circuit 31 reduce the interphase voltage as in the first embodiment. Here, a comparative example is shown in FIG. 15, and the terminal voltage and the phase voltage in the V-connected circuit configuration of FIG. 15 will be described.

In the circuit configuration of FIG. 15, the resonant circuit includes coils Lu and Lv and capacitors Cu and Cv connected in series to the coils Lu and Lv, and these are V-connected. The same applies to both the power transmission side and the power reception side.

In this case, the magnitude of the phase voltage (U-phase voltage, V-phase voltage, both vector values) at the connection points Na and Nb between the coils Lu and Lv and the capacitors Cu and Cv is the same value for each phase. The phase is shifted by 60 degrees. This phase voltage corresponds to the voltage between terminals. The magnitude of the phase voltage (Pa, Pb, both vector values) is √3 times the magnitude of the phase voltage as shown in the voltage vector diagram of the phase voltage and the phase voltage (see FIG. 15B). It becomes.

Next, the terminal voltage (phase voltage) and the phase voltage in the circuit configuration of the present embodiment will be described with reference to FIG. For the same reason as in the first embodiment, as shown in FIG. 14B, the magnitudes of the interphase voltages Puv1 and Puv2 are 1/2 × √3 times the magnitudes of the phase voltages Pu and Pv. Since the circuit configurations of the power transmission side and the power reception side are the same, only the power transmission side will be described, and the description of the power reception side will be omitted.

Therefore, in the fourth embodiment as well as in the first embodiment, the interphase voltage can be reduced on both the power transmission side and the power reception side as compared with the circuit configuration of FIG. As a result, the thickness of the insulating layer of the power transmission coils 26u and 26v can be reduced. Similarly, the thickness of the insulating layer of the power receiving coils 36u and 36v can be reduced. Further, since the power transmission coils 26u and 26v and the power reception coils 36u and 36v are not actually divided and configured, the wiring is easy.

(Other embodiments)
The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention. In the following, the parts that are the same or equal to each other in each embodiment are designated by the same reference numerals, and the description thereof will be referred to for the portions having the same reference numerals.

-In the above embodiment, the capacitor capacities of the first power transmission side capacitors 25u, 25v, 25w and the second power transmission side capacitors 27u, 27v, 27w are the same, but may be different. Even in this case, the interphase voltage can be reduced. Similarly, the capacitor capacities of the power receiving side first capacitors 35u, 35v, 35w and the power receiving side second capacitors 37u, 37v, 37w may be different.

-In the above embodiment, the power transmission side first capacitor 25u, 25v, 25w and the power transmission side second capacitor 27u, 27v, 27w are a plurality of capacitors (for example, a ceramic capacitor for mounting on a board) as shown in FIG. ) May be configured by connecting a plurality of series connectors in parallel. The same applies to the first capacitors 35u, 35v, 35w on the power receiving side and the second capacitors 37u, 37v, 37w on the power receiving side.

-In the above embodiment, the first capacitors 25u, 25v, 25w on the power transmission side and the first capacitors 35u, 35v, 35w on the power reception side are provided, but only one of them (the power transmission side or the power reception side) may be provided.

-In the above embodiment, the power transmission side resonance portions 20a to 20c are star-connected, delta-connected, or V-connected, but as shown in FIG. 17, each phase coil may be provided in parallel. Although the case of three-phase power feeding is shown in FIG. 17, it may be two-phase or four-phase or more. In this case as well, the interphase voltage can be reduced in the same manner. In addition, each phase coil may be provided in parallel also in the power receiving side resonance portions 30a to 30c.

10 ... non-contact power supply system, 12 ... in-vehicle battery, 20 ... power transmission device, 20a, 20b, 20c ... power transmission side resonance part, 25u, 25v, 25w ... power transmission side first capacitor, 26u, 26v, 26w ... power transmission coil, 27u , 27v, 27w ... Power transmission side second capacitor, 30 ... Power receiving device, 30a, 30b, 30c ... Power receiving side resonance part, 35u, 35v, 35w ... Power receiving side first capacitor, 36u, 36v, 36w ... Power receiving coil, 37u, 37v, 37w ... Second capacitor on the power receiving side, N2 ... Neutral point, N3 ... Neutral point.

Claims (10)

A non-contact power supply system that transmits power in a non-contact manner between a power transmission device (20,120) provided outside the vehicle and a power receiving device (30,130) provided in the vehicle to charge a storage battery (12) provided in the vehicle. In the power transmission device of (10)
Equipped with a power transmission unit (24,124) to which a multi-phase alternating current is input,
The power transmission unit is provided with a power transmission side resonance unit (20a to 20c, 120a, 120b) for each phase.
Each of the power transmission side resonance portions includes a power transmission coil (26u, 26v, 26w, 126u, 126v) and a first capacitor (25u, 25v, 25w, 125u, 125v) connected in series to one end of the power transmission coil. A power transmission device having a second capacitor (27u, 27v, 27w, 127u, 127v) connected in series to the other end. A non-contact power supply system (10) that transmits power in a non-contact manner between a power transmission device (20) provided outside the vehicle and a power receiving device (30) provided in the vehicle to charge a storage battery (12) provided in the vehicle. In power transmission equipment
Of the three-phase currents, the U-phase power transmission side resonant portion (20a) having the U-phase power transmission coil (26u) to which the U-phase current is input,
Of the three-phase currents, the V-phase power transmission side resonant portion (20b) having the V-phase power transmission coil (26v) to which the V-phase current is input, and
A W-phase power transmission side resonance portion (20c) having a W-phase power transmission coil (26w) to which a W-phase current is input among the three-phase currents is provided.
Each of the power transmission side resonance portions has a first capacitor (25u, 25v, 25w) connected in series to one end of the power transmission coil, and a second capacitor (27u, 27v, 27w) connected in series to the other end. Have,
A power transmission device in which one end of each of the power transmission side resonance portions is connected to the neutral point (N2), while the current of each phase is input from the other end. A non-contact power supply system (10) that transmits power in a non-contact manner between a power transmission device (20) provided outside the vehicle and a power receiving device (30) provided in the vehicle to charge a storage battery (12) provided in the vehicle. In power transmission equipment
Of the three-phase currents, the U-phase power transmission side resonant portion (20a) having the U-phase power transmission coil (26u) to which the U-phase current is input,
Of the three-phase currents, the V-phase power transmission side resonant portion (20b) having the V-phase power transmission coil (26v) to which the V-phase current is input, and
A W-phase power transmission side resonance portion (20c) having a W-phase power transmission coil (26w) to which a W-phase current is input among the three-phase currents is provided.
Each of the power transmission side resonance portions has a first capacitor (25u, 25v, 25w) connected in series to one end of the power transmission coil, and a second capacitor (27u, 27v, 27w) connected in series to the other end. Have,
The power transmission side resonance portion is a power transmission device connected by delta connection. The power transmission device according to claim 1, wherein each of the power transmission side resonance portions is connected in parallel. The circuit configuration of each power transmission side resonance portion is symmetrical with respect to the power transmission coil.
The power transmission device according to any one of claims 1 to 4, wherein the capacities of the first capacitor and the second capacitor are set to be the same in each of the power transmission side resonance portions. A non-contact power supply system that transmits power in a non-contact manner between a power transmission device (20,120) provided outside the vehicle and a power receiving device (30, 130) provided in the vehicle to charge a storage battery (12) provided in the vehicle. In the power receiving device of (10)
Equipped with a power receiving unit (34,134) that outputs multi-phase alternating current,
The power receiving unit is provided with a power receiving side resonance unit (30a to 30c, 130a, 130b) for each phase.
Each of the power receiving side resonance portions includes a power receiving coil (36u, 36v, 36w, 136u, 136v) and a first capacitor (35u, 35v, 35w, 135u, 135v) connected in series to one end of the power receiving coil. A power receiving device having a second capacitor (37u, 37v, 37w, 137u, 137v) connected in series to the other end. A non-contact power supply system (10) that transmits power in a non-contact manner between a power transmission device (20) provided outside the vehicle and a power receiving device (30) provided in the vehicle to charge a storage battery (12) provided in the vehicle. In the power receiving device
Of the three-phase currents, the U-phase power receiving side resonance portion (30a) having the U-phase power receiving coil (36u) from which the U-phase current is output, and
Of the three-phase currents, the V-phase power receiving side resonance portion (30b) having the V-phase power receiving coil (36v) from which the V-phase current is output, and
Of the three-phase current, the W-phase power receiving side resonance portion (30c) having the W-phase power receiving coil (36w) from which the W-phase current is output is provided.
Each of the power receiving side resonance portions includes a first capacitor (35u, 35v, 35w) connected in series to one end of the power receiving coil, and a second capacitor (37u, 37v, 37w) connected in series to the other end. Have,
A power receiving device in which one end of each of the power receiving side resonance portions is connected to the neutral point (N3), while the current of each phase is output from the other end. A non-contact power supply system (10) that transmits power in a non-contact manner between a power transmission device (20) provided outside the vehicle and a power receiving device (30) provided in the vehicle to charge a storage battery (12) provided in the vehicle. In the power receiving device
Of the three-phase currents, the U-phase power receiving side resonance portion (30a) having the U-phase power receiving coil (36u) from which the U-phase current is output, and
Of the three-phase currents, the V-phase power receiving side resonance portion (30b) having the V-phase power receiving coil (36v) from which the V-phase current is output, and
Of the three-phase current, the W-phase power receiving side resonance portion (30c) having the W-phase power receiving coil (36w) from which the W-phase current is output is provided.
Each of the power receiving side resonance portions includes a first capacitor (35u, 35v, 35w) connected in series to one end of the power receiving coil, and a second capacitor (37u, 37v, 37w) connected in series to the other end. Have,
The power receiving side resonance portion is a power receiving device connected by delta connection. The power receiving device according to claim 6, wherein each of the power receiving side resonance portions is connected in parallel. The circuit configuration of each of the power receiving side resonance portions is symmetrical with respect to the power receiving coil.
The power receiving device according to any one of claims 6 to 9, wherein the capacities of the first capacitor and the second capacitor are set to be the same in each of the power receiving side resonance portions.

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