Power transmission device for non-contact power supply system

Abstract

A power transmission device for a non-contact power supply system includes a processor configured to acquire information of a power reception device mounted on a vehicle, and change an end condition for power supply to the power reception device based on the acquired information of the power reception device.

Description

POWER TRANSMISSION DEVICE FOR NON-CONTACT POWER SUPPLY SYSTEM

[0001] The present disclosure relates to a power transmission device for a non-contact power supply system.

[0002] Patent Literature 1 discloses a technique for determining an amount of power to be supplied to a vehicle according to a positional relationship between a power transmission device and a power reception device based on power transmission device information regarding the power transmission device and power reception device information regarding one or more power reception devices provided in the vehicle.

[0003] JP 2024-122073 A

[0004] In the technique disclosed in Patent Literature 1, depending on a combination of systems on a power transmission device side (ground side) and a power reception device side (vehicle side), coils or circuit configurations may be mismatched, and a failure may occur at a time of power supply.

[0005] The present disclosure has been made in view of the above, and an object of the present disclosure is to provide a power transmission device for a non-contact power supply system capable of switching control of power supply according to a combination of systems on a power transmission device side and a power reception device side.

[0006] According to one aspect of the present disclosure, there is provided a power transmission device for a non-contact power supply system including a processor configured to acquire information of a power reception device mounted on a vehicle, and change an end condition for power supply to the power reception device based on the acquired information of the power reception device.

[0007] According to the present disclosure, it is possible to switch power supply control according to a combination of systems on a power transmission device side and a power reception device side.

[0008] FIG. 1 is a diagram illustrating a schematic configuration of a non-contact power supply system according to an embodiment.FIG. 2 is a diagram illustrating a specific configuration of a first example (system A) of the non-contact power supply system according to the embodiment.FIG. 3 is a diagram illustrating a specific configuration of a second example (system B) of the non-contact power supply system according to the embodiment.FIG. 4 is a flowchart illustrating a first example of a power supply control method by a power transmission device for a non-contact power supply system according to the embodiment.FIG. 5 is a flowchart illustrating a second example of the power supply control method by the power transmission device for the non-contact power supply system according to the embodiment.

[0009] A power transmission device for a non-contact power supply system according to an embodiment of the present disclosure will be described with reference to the drawings. Note that components in the following embodiment include components that those skilled in the art can easily replace or components that are substantially the same.

[0010] (Schematic configuration of non-contact power supply system) A schematic configuration of a non-contact power supply system according to an embodiment will be described with reference to FIG. 1. The non-contact power supply system according to the embodiment is a wireless power transfer system that supplies power to a traveling or stopping vehicle in a contactless manner by using, for example, magnetic resonance coupling (magnetic field resonance). A vehicle to which power is to be supplied is an electric vehicle that can be charged with power supplied from an external power supply, and is, for example, a battery electric vehicle (BEV), a plug-in hybrid electric vehicle (PHEV), or the like.

[0011] A non-contact power supply system 1 includes a power transmission device 11 and a power reception device 12. The power transmission device 11 includes a power transmission ECU 111, a communication device 112, a power transmission coil 113, a resonant circuit 114, a filter circuit 115, an inverter 116, and a power supply 117. Note that the power transmission device 11 may include a power factor collection (PFC) circuit including an AC / DC converter between the inverter 116 and the power supply 117.

[0012] The power transmission ECU 111 is an electronic control unit that controls the power transmission device 11. The power transmission ECU 111 includes a processor and a memory. The processor includes a central processing unit (CPU), a digital signal processor (DSP), a field-programmable gate array (FPGA), and the like. Note that the processor may include a control device (a device not using a semiconductor) other than a semiconductor device. The memory is a main storage device, and includes a random access memory (RAM), a read only memory (ROM), and the like. The power transmission ECU 111 loads a program stored in a predetermined storage unit into a work area of the memory (main storage device) and executes the program, and controls each component and the like through the execution of the program, thereby implementing a function that matches a predetermined purpose.

[0013] The power transmission ECU 111 can adjust (limit) power to be transmitted to the power reception device 12 (power for power transmission) by, for example, controlling a switching element included in the inverter 116. Furthermore, the power transmission ECU 111 may adjust the power to be transmitted to the power reception device 12, by controlling a duty cycle and drive frequency of the inverter 116 and voltage of the power supply 117. Details of the control by the power transmission ECU 111 will be described later.

[0014] The communication device 112 communicates with a communication device 122 of the power reception device 12 with short-range wireless communication or wide-area wireless communication. The communication device 112 communicates with the communication device 122 to acquire a power requirement value (amount of power required) of the vehicle, vehicle identification information (vehicle ID), and the like.

[0015] The short-range wireless communication is, for example, communication with a communication distance of less than 10 meters, and is communication with a short communication distance as compared with the wide-area wireless communication. As the short-range wireless communication, for example, communication conforming to any communication standard formulated by IEEE, ISO, IEC, or the like can be used. Furthermore, as the short-range wireless communication, for example, Wi-Fi (registered trademark), Bluetooth (registered trademark), ZigBee (registered trademark), or the like can be used. Furthermore, as a technique for performing short-range wireless communication, radio frequency identification (RFID), dedicated short range communication (DSRC), or the like may be used.

[0016] The wide-area wireless communication is, for example, communication with a communication distance of 10 meters to 10 kilometers, and is communication with a long communication distance as compared with the short-range wireless communication. As the wide-area wireless communication, for example, communication conforming to communication standards such as 3GPP (registered trademark), 4G, LTE, 5G, and WiMAX formulated by IEEE can be used.

[0017] The power transmission coil (primary coil) 113 is embedded in a lane on a road, for example. A plurality of the power transmission coils 113 may be arranged along the lane on the road. In the power transmission device 11, when AC power is supplied from the filter circuit 115 to the resonant circuit 114, current flows through the power transmission coil 113, and a magnetic field for power transmission is generated.

[0018] The resonant circuit 114 includes, for example, a plurality of resonant capacitors. Furthermore, a resonance frequency of the resonant circuit 114 is 10 kHz to 100 GHz, preferably 85 kHz. Furthermore, the resonance frequency of the resonant circuit 114 is configured to coincide with the drive frequency of the inverter 116.

[0019] The filter circuit 115 reduces noise included in AC current input from the inverter 116, and outputs, to the resonant circuit 114, the AC power from which the noise has been reduced. The filter circuit 115 includes, for example, an LC filter, band pass filter (BPF), immittance filter, or the like in which inductors (variable inductors) and capacitors (variable capacitors) are combined.

[0020] The inverter 116 converts DC power input from the power supply 117 into AC power and outputs the AC power to the filter circuit 115. The inverter 116 includes, for example, a switching element such as an insulated gate bipolar transistor (IGBT), a metal-oxide-semiconductor field effect transistor, (MOSFET) or the like. Furthermore, the drive frequency of the inverter 116 is, for example, 85 kHz.

[0021] The power supply 117 includes, for example, a commercial power supply.

[0022] The power reception device 12 is provided, for example, at a bottom of a vehicle body of the vehicle. Furthermore, the power reception device 12 includes a vehicle ECU 121, the communication device 122, a power reception coil 123, a resonant circuit 124, a filter circuit 125, a rectifier 126, and a battery 127.

[0023] The vehicle ECU 121 is an electronic control unit that controls the vehicle. The vehicle ECU 121 has a hardware configuration similar to a hardware configuration of the power transmission ECU 111. The vehicle ECU 121 can adjust (limit) power (power for charging) supplied to the battery 127 by controlling a switching element included in the rectifier 126. Furthermore, the vehicle ECU 121 may adjust the power to be supplied to the battery 127 by controlling, for example, a variable inductor, a variable capacitor, a DC / DC converter, or the like included in the power reception device 12.

[0024] The communication device 122 communicates with the communication device 112 of the power transmission device 11 with the short-range wireless communication or the wide-area wireless communication. The communication device 122 communicates with the communication device 112 to transmit the power requirement value (amount of power required) of the vehicle, the vehicle identification information (vehicle ID), and the like.

[0025] The power reception coil (secondary coil) 123 receives the power transferred from the power transmission coil 113 in a contactless manner. That is, in the non-contact power supply system 1, for example, when the vehicle travels on the road on which the power transmission coil 113 is installed, the power transmission coil 113 on a ground side and the power reception coil 123 on a vehicle side face each other in a vertical direction, by which power is transferred in a contactless manner.

[0026] The resonant circuit 124 includes, for example, a plurality of resonant capacitors. The resonance frequency of the resonant circuit 124 is determined to coincide with the resonance frequency of the resonant circuit 114.

[0027] The filter circuit 125 reduces noise included in AC current input from the resonant circuit 124, and outputs, to the rectifier 126, the AC power from which the noise has been reduced. The filter circuit 125 includes, for example, an LC filter, band pass filter (BPF), immittance filter, or the like in which inductors (variable inductors) and capacitors (variable capacitors) are combined.

[0028] The rectifier 126 converts the AC power input from the filter circuit 125 into DC power and outputs the DC power to the battery 127. The rectifier 126 includes, for example, a full-bridge circuit in which four diodes are full-bridge connected as rectifier elements. Furthermore, a switching element is connected in parallel to each diode of the rectifier 126. Each of these switching elements includes for example, an IGBT, and performs switching operation in accordance with a control signal from the vehicle ECU 121.

[0029] The battery 127 is a DC power supply that can be charged, and includes, for example, a lithium ion battery, a nickel-metal hydride battery, or the like. The battery 127 stores the power supplied from the power transmission device 11 to the power reception device 12. Furthermore, the battery 127 is electrically connected to a traction motor via a separately provided power control unit (PCU), and can supply power to the traction motor.

[0030] (Specific configuration of non-contact power supply system) A specific configuration of the non-contact power supply system according to the embodiment will be described with reference to FIGS. 2 and 3. Hereinafter, two types of non-contact power supply systems will be described.

[0031] <System A> FIG. 2 illustrates configurations of the power transmission device 11 and the power reception device 12 in a first example of the non-contact power supply system according to the embodiment. In the present embodiment, the power transmission device 11 and the power reception device 12 illustrated in FIG. 2 are also referred to as "system A". In the system A, each of the power transmission device 11 and the power reception device 12 includes a mechanism (hereinafter, referred to as a "first mechanism") that maintains (does not change) an output characteristic of the power. Furthermore, the system A is characterized in that output current of the power transmission coil 113 increases when the power transmission coil 113 on the ground side and the power reception coil 123 on the vehicle side are not facing each other in the vertical direction (when there is no vehicle).

[0032] In the power transmission device 11, the resonant circuit 114 includes two resonant capacitors 114a connected in series to one end and another end of the power transmission coil 113. Furthermore, the filter circuit 115 includes a band pass filter including two inductors 115a and three capacitors 115b. Furthermore, the inverter 116 includes four switching elements 116a and one capacitor 116b.

[0033] In the power transmission device 11 according to the system A, the filter circuit 115 functions as the first mechanism that maintains (does not change) the output characteristic of the power. That is, as illustrated in FIG. 2, a voltage source characteristic is constant (constant voltage) on upstream and downstream of the filter circuit 115, and the output characteristic does not change.

[0034] In the power reception device 12, the resonant circuit 124 includes two resonant capacitors 124a connected in series to one end and another end of the power reception coil 123. Furthermore, similarly to the filter circuit 115 of the power transmission device 11, the filter circuit 125 includes a band pass filter including two inductors 125a and three capacitors 125b. Furthermore, the rectifier 126 includes four switching elements 126a and one capacitor 126b.

[0035] In the power reception device 12 according to the system A, the filter circuit 125 functions as the first mechanism that maintains (does not change) the output characteristic of the power. That is, as illustrated in FIG. 2, a current source characteristic is constant (constant current) on upstream and downstream of the filter circuit 125, and the output characteristic does not change. Note that, as illustrated in FIG. 2, a non-contact power supply system according to the system A has a characteristic of switching from the voltage source characteristic to the current source characteristic when switching from power transmission to power reception is performed.

[0036] <System B> FIG. 3 illustrates configurations of the power transmission device 11 and the power reception device 12 in a second example of the non-contact power supply system according to the embodiment. In the present embodiment, the power transmission device 11 and the power reception device 12 illustrated in FIG. 3 are also referred to as "system B". In the system B, each of the power transmission device 11 and the power reception device 12 includes a mechanism (hereinafter, referred to as a "second mechanism") that changes the output characteristic of the power. Furthermore, the system B is characterized in that output current of the power transmission coil 113 decreases when the power transmission coil 113 on the ground side and the power reception coil 123 on the vehicle side are not facing each other in the vertical direction (when there is no vehicle).

[0037] In the power transmission device 11, the resonant circuit 114 includes two resonant capacitors 114a connected in series to one end and another end of the power transmission coil 113. Furthermore, the filter circuit 115 includes an immittance filter including four inductors 115a and one capacitor 115b. Furthermore, the inverter 116 includes four switching elements 116a and one capacitor 116b.

[0038] In the power transmission device 11 according to the system B, the filter circuit 115 functions as the second mechanism that changes the output characteristic of the power. That is, as illustrated in FIG. 3, the voltage source characteristic (constant voltage) is provided on a front side (left side in the drawing) of the filter circuit 115, but the current source characteristic (constant current) is provided on a rear side (right side in the drawing) of the filter circuit 115, and the output characteristic changes.

[0039] In the power reception device 12, the resonant circuit 124 includes two resonant capacitors 124a connected in series to one end and another end of the power reception coil 123. Furthermore, similarly to the filter circuit 115 of the power transmission device 11, the filter circuit 125 includes an immittance filter including four inductors 115a and one capacitor 115b. Furthermore, the rectifier 126 includes four switching elements 126a and one capacitor 126b.

[0040] In the power reception device 12 according to the system B, the filter circuit 125 functions as the second mechanism that changes the output characteristic of the power. That is, as illustrated in FIG. 3, the voltage source characteristic (constant voltage) is provided on a front side (left side in the drawing) of the filter circuit 125, but the current source characteristic (constant current) is provided on a rear side (right side in the drawing) of the filter circuit 125, and the output characteristic changes. Note that, as illustrated in FIG. 3, a non-contact power supply system according to the system B has a characteristic of switching from the current source characteristic to the voltage source characteristic when switching from power transmission to power reception is performed.

[0041] (Details of power supply control) Based on the above, the power supply control performed by the power transmission ECU 111 of the power transmission device 11 will be described in detail.

[0042] First, the power transmission ECU 111 acquires information of the power reception device 12 mounted on the vehicle. Examples of the information on the power reception device 12 include information about which system, the system A or B the power reception device 12 is, that is, which mechanism, the first mechanism (the filter circuit 125 in FIG. 2) or the second mechanism (the filter circuit 125 in FIG. 3), the power reception device 12 includes.

[0043] The power transmission ECU 111 acquires information of the power reception device 12 with wide-area communication, short-range communication, or the like using the communication device 112, for example. Furthermore, the power transmission ECU 111 may acquire the information of the power reception device 12 by utilizing, for example, a weak power transmission phase (a phase of checking whether the power reception device 12 is a voltage source or a current source by causing a short-circuit state) in a tracking mode in the non-contact power supply.

[0044] Subsequently, the power transmission ECU 111 changes an end condition for the power supply to the power reception device 12 based on the acquired information of the power reception device 12. For example, in a case where the power reception device 12 is the system A (refer to FIG. 2), the power transmission ECU 111 changes the end condition for the power supply to one of the following conditions. Note that, in the present embodiment, the end condition for the power supply described below is referred to as a "first power supply end condition". (1) When the current (output current of the inverter 116, output current of the power transmission coil 113) exceeds a predetermined threshold Th1 during the power supply to the power reception device 12, the power supply ends. (2) When a phase difference between the current and the voltage exceeds a predetermined threshold Th2, the power supply ends.

[0045] Furthermore, for example, in a case where the power reception device 12 is the system B (refer to FIG. 3), the power transmission ECU 111 changes the end condition for the power supply to one of the following conditions. Note that, in the present embodiment, the end condition for the power supply described below is referred to as a "second power supply end condition". (1) When the current (output current of the inverter 116, output current of the power transmission coil 113) is below a predetermined threshold Th3 during the power supply to the power reception device 12, the power supply ends. (2) When the phase difference between the current and the voltage exceeds a predetermined threshold Th4 (threshold Th4 < threshold Th2), the power supply ends.

[0046] In this regard, however, the power transmission ECU 111 does not judge the power supply end condition described above during the tracking mode in the non-contact power supply (weak power transmission phase when checking coupling between the power transmission device 11 and the power reception device 12) or when power requirement from the vehicle is 0.

[0047] As described above, in the power transmission device 11, the end condition for the power supply to the power reception device 12 can be switched according to the system on a power reception device 12 side. As a result, regardless of the type of the system on the power reception device 12 side, power can be safely supplied.

[0048] Here, in the non-contact power supply system according to the embodiment, the power transmission device 11 may be provided with the first mechanism (the filter circuit 115 in FIG. 2) and the second mechanism (the filter circuit 115 in FIG. 3) so as to be switchable, and power may be supplied after switching to either mechanism according to the configuration of the power reception device 12.

[0049] In this case, based on the acquired information of the power reception device 12, the power transmission ECU 111 switches to either the first mechanism (the filter circuit 115 in FIG. 2) or the second mechanism (the filter circuit 115 in FIG. 3) to supply power to the power reception device 12. That is, in a case where the power reception device 12 includes the first mechanism (the filter circuit 125 in FIG. 2), the power transmission device 11 is also switched to the first mechanism (the filter circuit 115 in FIG. 2) to transmit power. Meanwhile, in a case where the power reception device 12 includes the second mechanism (the filter circuit 125 in FIG. 3), the power transmission device 11 is also switched to the second mechanism (the filter circuit 115 in FIG. 3) to transmit power. In this case, the first mechanism is a resonant filter, and the second mechanism is an immittance filter. Furthermore, a switching mechanism including, for example, a switch, a relay, and a semiconductor element (switching element or the like) may be used for switching the first mechanism and the second mechanism.

[0050] As described above, in the power transmission device 11, the system on a power transmission device 11 side can be switched according to the system on the power reception device 12 side. As a result, regardless of the type of the system on the power reception device 12 side, power can be safely supplied.

[0051] Furthermore, in the non-contact power supply system according to the embodiment, switching between the first mechanism and the second mechanism may be achieved by causing a band pass filter having a capacitor that can be branched to function as a resonant filter or an immittance filter.

[0052] In this case, the filter circuit 115 includes a band pass filter having a capacitor that can be branched. Then, by not branching the capacitor of the band pass filter, the band pass filter is caused to function as a resonant filter to implement the first mechanism. Furthermore, by branching the capacitor of the band pass filter, the band pass filter is caused to function as an immittance filter to implement the second mechanism.

[0053] As described above, in the power transmission device 11, the system on the power transmission device 11 side can be switched according to the system on the power reception device 12 side by using an existing band pass filter. As a result, regardless of the type of the system on the power reception device 12 side, power supply can be safely performed while preventing an increase in size of the power transmission device 11.

[0054] Furthermore, in the non-contact power supply system according to the embodiment, switching between the first mechanism and the second mechanism may be achieved by causing a fourth-order filter having a capacitor that can be branched to function as a resonant filter or an immittance filter.

[0055] In this case, the filter circuit 115 includes a fourth-order filter having a capacitor that can be branched. Then, by not branching the capacitor of the fourth-order filter, the fourth-order filter is caused to function as a resonant filter to implement the first mechanism. Furthermore, by branching the capacitor of the fourth-order filter, the fourth-order filter is caused to function as an immittance filter to implement the second mechanism.

[0056] As described above, in the power transmission device 11, the system on the power transmission device 11 side can be switched according to the system on the power reception device 12 side by using a fourth-order filter. As a result, regardless of the type of the system on the power reception device 12 side, power supply can be safely performed while preventing an increase in size of the power transmission device 11.

[0057] Furthermore, in the non-contact power supply system according to the embodiment, switching between the first mechanism and the second mechanism may be achieved by causing a predetermined filter to function as a resonant filter or an immittance filter.

[0058] In this case, the filter circuit 115 includes a filter having a plurality of coils and two capacitors. The filter circuit 115 is an immittance filter on which two capacitors, which are twice a normal capacitor, are mounted. Then, by using both the two capacitors, the above-described filter functions as a resonant filter to implement the first mechanism. Furthermore, by using either one of the two capacitors, the above-described filter functions as an immittance filter (genuine immittance filter) to implement the second mechanism.

[0059] As described above, in the power transmission device 11, the system on the power transmission device 11 side can be switched according to the system on the power reception device 12 side by using an immittance filter on which two capacitors, which are twice a normal capacitor, are mounted. As a result, regardless of the type of the system on the power reception device 12 side, power can be safely supplied.

[0060] Furthermore, although a case where the functions of the first mechanism and the second mechanism are implemented by the filter circuit 115 has been described above, the functions of the first mechanism and the second mechanism may be implemented by means other than the filter circuit 115.

[0061] For example, in the power transmission device 11 (refer to FIG. 2) of the system A, the functions of the first mechanism and the second mechanism may be implemented by providing a switching mechanism that switches connection between the power transmission coil 113 and the resonant capacitors 114a to series or parallel. The switching mechanism includes, for example, a switch, a relay, and a semiconductor element (switching element or the like).

[0062] In this case, upon acquiring information that the power reception device 12 is the system A including the first mechanism (for example, the filter circuit 125 in FIG. 2), the power transmission ECU 111 switches the connection between the power transmission coil 113 and the resonant capacitors 114a to series with the switching mechanism. Subsequently, the power transmission ECU 111 supplies power to the power reception device 12, and ends the power supply when, for example, the current exceeds a predetermined threshold during the power supply to the power reception device 12. Note that, when the power transmission coil 113 and the resonant capacitors 114a are connected in series at a time when the information of the power reception device 12 is acquired, the switching mechanism may not be operated.

[0063] Meanwhile, upon acquiring information that the power reception device 12 is the system B including the second mechanism (for example, the filter circuit 125 in FIG. 3), the power transmission ECU 111 switches the connection between the power transmission coil 113 and the resonant capacitors 114a to parallel with the switching mechanism. Subsequently, the power transmission ECU 111 supplies power to the power reception device 12, and ends the power supply when, for example, the current falls to lower than the predetermined threshold during the power supply to the power reception device 12. Note that, when the power transmission coil 113 and the resonant capacitors 114a are connected in parallel at a time when the information of the power reception device 12 is acquired, the switching mechanism may not be operated.

[0064] As described above, in the power transmission device 11, the system on the power transmission device 11 side can be switched according to the system on the power reception device 12 side by switching the connection between the power transmission coil 113 and the resonant capacitors 114a to series or parallel. As a result, regardless of the type of the system on the power reception device 12 side, power can be safely supplied. Note that, although an example in which the power transmission device 11 (refer to FIG. 2) according to the system A is a main has been described in the above description, similar control can be performed also in a case where the power transmission device 11 (refer to FIG. 2) according to the system B is the main.

[0065] Furthermore, the functions of the first mechanism and second mechanism may be implemented by, for example, providing, between the power transmission coil 113 and power reception coil 123 of the power transmission device 11 (refer to FIG. 2) according to the system A, a split coil for changing the output characteristic.

[0066] In this case, upon acquiring information that the power reception device 12 is the system A including the first mechanism (for example, the filter circuit 125 in FIG. 2), the power transmission ECU 111 does not change the output characteristic with the split coil at a time of the power transmission (the split coil is not used). Subsequently, the power transmission ECU 111 supplies power to the power reception device 12, and ends the power supply when, for example, the current exceeds the predetermined threshold during the power supply to the power reception device 12.

[0067] Meanwhile, upon acquiring information that the power reception device 12 is the system B including the second mechanism (for example, the filter circuit 125 in FIG. 3), the power transmission ECU 111 changes the output characteristic with the split coil at the time of the power transmission (the split coil is used). Subsequently, the power transmission ECU 111 supplies power to the power reception device 12, and ends the power supply when, for example, the current falls to lower than the predetermined threshold during the power supply to the power reception device 12.

[0068] For example, in the non-contact power supply system according to the system A, the output characteristic changes as "voltage source characteristic -> current source characteristic" (refer to FIG. 2) when switching from the power transmission to the power reception. However, the output characteristic changes as "voltage source characteristic -> current source characteristic -> voltage source characteristic" by using the split coil. Therefore, even when the power transmission device 11 is the system A and the power reception device 12 is the system B in combination, power can be supplied without any trouble.

[0069] Furthermore, for example, in the non-contact power supply system according to the system B, the output characteristic changes as "current source characteristic -> voltage source characteristic" (refer to FIG. 2) when switching from the power transmission to the power reception. However, the output characteristic changes as "current source characteristic -> voltage source characteristic -> current source characteristic" by using the split coil. Therefore, even when the power transmission device 11 is the system B and the power reception device 12 is the system A in combination, power can be supplied without any trouble.

[0070] Note that, although an example in which the power transmission device 11 (refer to FIG. 2) according to the system A is a main has been described in the above description, similar control can be performed also in a case where the power transmission device 11 (refer to FIG. 2) according to the system B is the main.

[0071] Furthermore, for example, the functions of the first mechanism and second mechanism may be implemented by providing a DC / DC converter in a preceding stage of the inverter 116 of the power transmission device 11 (refer to FIG. 2) according to the system A.

[0072] In this case, upon acquiring information that the power reception device 12 is the system A including the first mechanism (for example, the filter circuit 125 in FIG. 2), the power transmission ECU 111 does not change, with the DC / DC converter, voltage supplied to the inverter 116 at the time of the power transmission (the DC / DC converter is not used). Subsequently, the power transmission ECU 111 supplies power to the power reception device 12, and ends the power supply when, for example, the current exceeds the predetermined threshold during the power supply to the power reception device 12.

[0073] Meanwhile, upon acquiring information that the power reception device 12 is the system B including the second mechanism (for example, the filter circuit 125 in FIG. 3), the power transmission ECU 111 changes, with the DC / DC converter, the voltage supplied to the inverter 116 at the time of the power transmission (the DC / DC converter is used). Subsequently, the power transmission ECU 111 supplies power to the power reception device 12, and ends the power supply when, for example, the current falls to lower than the predetermined threshold during the power supply to the power reception device 12.

[0074] As described above, in the power transmission device 11, the system on the power transmission device 11 side can be switched according to the system on the power reception device 12 side by using a DC / DC converter. As a result, regardless of the type of the system on the power reception device 12 side, power can be safely supplied. Note that, although an example in which the power transmission device 11 (refer to FIG. 2) according to the system A is a main has been described in the above description, similar control can be performed also in a case where the power transmission device 11 (refer to FIG. 2) according to the system B is the main.

[0075] Furthermore, for example, the functions of the first mechanism and second mechanism may be implemented by power control of the inverter 116 of the power transmission device 11 (refer to FIG. 2) according to the system A.

[0076] In this case, upon acquiring information that the power reception device 12 is the system A including the first mechanism (for example, the filter circuit 125 in FIG. 2), the power transmission ECU 111 switches the power control of the inverter 116 to frequency control at the time of the power transmission, and supplies power to the power reception device 12. Then, the power transmission ECU 111 ends the power supply when the current exceeds the predetermined threshold during the power supply to the power reception device 12.

[0077] Meanwhile, upon acquiring information that the power reception device 12 is the system B including the second mechanism (for example, the filter circuit 125 in FIG. 3), the power transmission ECU 111 switches the power control of the inverter 116 to duty cycle control at the time of the power transmission, and supplies power to the power reception device 12. Then, the power transmission ECU 111 ends the power supply when the current falls to lower than the predetermined threshold during the power supply to the power reception device 12.

[0078] As described above, in the power transmission device 11, the system on the power transmission device 11 side can be switched according to the system on the power reception device 12 side by the power control of the inverter 116. As a result, regardless of the type of the system on the power reception device 12 side, power supply can be safely performed while preventing an increase in size of the power transmission device 11. Note that, although an example in which the power transmission device 11 (refer to FIG. 2) according to the system A is a main has been described in the above description, similar control can be performed also in a case where the power transmission device 11 (refer to FIG. 2) according to the system B is the main.

[0079] (Power supply control method 1) A first example of a power supply control method by the power transmission device for the non-contact power supply system according to the embodiment will be described with reference to FIG. 4. Hereinafter, an example of a case where the end condition for the power supply to the power reception device 12 is switched according to the system on the power reception device 12 side will be described.

[0080] First, the power transmission ECU 111 acquires information of the power reception device 12 with the wide-area communication or the like (step S1). Subsequently, the power transmission ECU 111 determines whether or not, for example, the power reception device 12 is the system A including the first mechanism (for example, the filter circuit 125 in FIG. 2) (step S2).

[0081] In a case where it is determined in step S2 that the power reception device 12 is the system A (Yes in step S2), the power transmission ECU 111 applies the first power supply end condition described above (step S3) and completes the present processing.

[0082] Meanwhile, in a case where it is determined in step S2 that the power reception device 12 is not the system A (No in step S2), the power transmission ECU 111 determines whether or not, for example, the power reception device 12 is the system B including the second mechanism (for example, the filter circuit 125 in FIG. 3) (step S4).

[0083] In a case where it is determined in step S4 that the power reception device 12 is the system B (Yes in step S4), the power transmission ECU 111 applies the second power supply end condition described above (step S5) and completes the present processing. Meanwhile, in a case where it is determined in step S4 that the power reception device 12 is not the system B (No in step S4), the power transmission ECU 111 completes the present processing.

[0084] (Power supply control method 2) A second example of the power supply control method by the power transmission device for the non-contact power supply system according to the embodiment will be described with reference to FIG. 5. Hereinafter, an example of a case where, according to the system on the power reception device 12 side, the system on the power transmission device 11 side is switched, and then the end condition for the power supply to the power reception device 12 is switched will be described.

[0085] First, the power transmission ECU 111 acquires information of the power reception device 12 with the wide-area communication or the like (step S11). Subsequently, the power transmission ECU 111 determines whether or not, for example, the power reception device 12 is the system A including the first mechanism (for example, the filter circuit 125 in FIG. 2) (step S12).

[0086] In a case where it is determined in step S12 that the power reception device 12 is the system A (Yes in step S12), the power transmission ECU 111 switches the power transmission device 11 to the system A including the first mechanism (for example, the filter circuit 115 in FIG. 2) (step S13), then applies the first power supply end condition described above (step S14) and completes the present processing.

[0087] Meanwhile, in a case where it is determined in step S12 that the power reception device 12 is not the system A (No in step S12), the power transmission ECU 111 determines whether or not, for example, the power reception device 12 is the system B including the second mechanism (for example, the filter circuit 125 in FIG. 3) (step S15).

[0088] In a case where it is determined in step S15 that the power reception device 12 is the system B (Yes in step S15), the power transmission ECU 111 switches the power transmission device 11 to the system B including the second mechanism (for example, the filter circuit 115 in FIG. 3) (step S16), then applies the second power supply end condition described above (step S17) and completes the present processing. Meanwhile, in a case where it is determined in step S15 that the power reception device 12 is not the system B (No in step S15), the power transmission ECU 111 completes the present processing.

[0089] According to the power transmission device for the non-contact power supply system according to the embodiment described above, it is possible to switch power supply control according to a combination of systems on the power transmission device 11 side and the power reception device 12 side. Furthermore, according to the power transmission device for the non-contact power supply system according to the embodiment, by switching the system on the power transmission device 11 side according to the system on the power reception device 12 side, power can be supplied by a combination of systems with high controllability. Furthermore, according to the power transmission device for the non-contact power supply system according to the embodiment, a power supply end judgement can be switched to the power reception device 12, and thus it is possible to construct a non-contact power supply system capable of supporting different types of power reception devices 12.

[0090] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the disclosure in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0091] 1 Non-contact power supply system 11 Power transmission device 111 Power transmission ECU 112 Communication device 113 Power transmission coil 114 Resonant circuit 114a Resonant capacitor 115 Filter circuit 115a Inductor 115b Capacitor 116 Inverter 116a Switching element 116b Capacitor 117 Power supply 12 Power reception device 121 Vehicle ECU 122 Communication device 123 Power reception coil 124 Resonant circuit 124a Resonant capacitor 125 Filter circuit 125a Inductor 125b Capacitor 126 Rectifier 126a Switching element 126b Capacitor 127 Battery

Claims

1. A power transmission device for a non-contact power supply system, the power transmission device comprising 　　　a processor configured to 　　　　　　acquire information of a power reception device mounted on a vehicle, and 　　　　　　change an end condition for power supply to the power reception device based on the acquired information of the power reception device.

2. The power transmission device according to claim 1, further comprising: 　　　a first mechanism configured to maintain an output characteristic of power; and 　　　a second mechanism configured to change the output characteristic of power, wherein 　　　the processor is configured to 　　　　　　switch to either the first mechanism or the second mechanism based on the acquired information of the power reception device, and supply power to the power reception device, 　　　　　　end the power supply when current exceeds a predetermined threshold during the power supply to the power reception device in a case of switching to the first mechanism, and 　　　　　　end the power supply when the current falls to lower than the predetermined threshold during the power supply to the power reception device in a case of switching to the second mechanism.

3. The power transmission device according to claim 2, wherein 　　　the first mechanism is a resonant filter, and 　　　the second mechanism is an immittance filter.

4. The power transmission device according to claim 2, further comprising a band pass filter including a capacitor, wherein, 　　　the first mechanism is the band pass filter functioning as a resonant filter by not branching the capacitor, and 　　　the second mechanism is the band pass filter functioning as an immittance filter by branching the capacitor.

5. The power transmission device according to claim 2, further comprising a fourth-order filter, wherein, 　　　the first mechanism is the fourth-order filter functioning as a resonant filter by not branching the capacitor, and 　　　the second mechanism is the fourth-order filter functioning as an immittance filter by branching the capacitor.

6. The power transmission device according to claim 2, further comprising a filter including a plurality of coils and two capacitors, wherein, 　　　the first mechanism is the filter functioning as a resonant filter by using both the two capacitors, and 　　　the second mechanism is the filter functioning as an immittance filter by using either one of the two capacitors.

7. The power transmission device according to claim 2, further comprising: 　　　a power transmission coil; 　　　a resonant capacitor connected to the power transmission coil; and 　　　a switching mechanism configured to switch connection between the power transmission coil and the resonant capacitor, wherein 　　　the processor is configured to 　　　　　　upon acquiring the information that the power reception device includes the first mechanism, switch the connection between the power transmission coil and the resonant capacitor to series with the switching mechanism and supplies the power to the power reception device, and end power supply when the current exceeds the predetermined threshold during the power supply to the power reception device, and 　　　　　　upon acquiring the information that the power reception device includes the second mechanism, switch the connection between the power transmission coil and the resonant capacitor to parallel with the switching mechanism and supply the power to the power reception device, and end the power supply when the current falls to lower than the predetermined threshold during the power supply to the power reception device.

8. The power transmission device according to claim 2, further comprising: 　　　a power transmission coil; and 　　　a split coil configured to change the output characteristic provided between the power transmission coil and a power reception coil of the power reception device, wherein 　　　the processor is configured to 　　　　　　upon acquiring the information that the power reception device includes the first mechanism, maintain the output characteristic by not using the split coil and supply the power to the power reception device, and end the power supply when the current exceeds the predetermined threshold during the power supply to the power reception device, and 　　　upon acquiring the information that the power reception device includes the second mechanism, change the output characteristic by using the split coil and supply the power to the power reception device, and end the power supply when the current falls to lower than the predetermined threshold during the power supply to the power reception device.

9. The power transmission device according to claim 2, further comprising: 　　　an inverter; and 　　　a DC / DC converter connected to a preceding stage of the inverter, wherein 　　　the processor is configured to 　　　　　　upon acquiring the information that the power reception device includes the first mechanism, maintain voltage supplied to the inverter with the DC / DC converter and supply the power to the power reception device, and end the power supply when the current exceeds the predetermined threshold during the power supply to the power reception device, and 　　　　　　upon acquiring the information that the power reception device includes the second mechanism, change the voltage supplied to the inverter with the DC / DC converter and supply the power to the power reception device, and end the power supply when the current falls to lower than the predetermined threshold during the power supply to the power reception device.

10. The power transmission device according to claim 2, further comprising an inverter, wherein 　　　the processor is configured to 　　　　　　in a case where the power reception device includes the first mechanism, switch power control of the inverter to frequency control and supply the power to the power reception device, and end the power supply when the current exceeds the predetermined threshold during the power supply to the power reception device, and 　　　　　　in a case where the power reception device includes the second mechanism, switch the power control of the inverter to duty cycle control and supply the power to the power reception device, and end the power supply when the current falls to lower than the predetermined threshold during the power supply to the power reception device.

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