CONTROL DEVICE, CONTROL METHOD, PROGRAM, AND NON-CONTACT POWER TRANSMISSION SYSTEM

Abstract

To provide a control device of a power transmission device capable of controlling transmission power according to a state of a power reception device without always communicating with the power reception device, in a non-contact power transmission system.SOLUTION: A control device according to the present disclosure is configured so as to execute determination processing of determining whether or not a power reception device is executing a suppression control based on output current and output voltage of an inverter which a power transmission device has, and power control processing of controlling transmission power of the power transmission device based on a result of the determination processing. The determination processing includes a calculation of an amplitude ratio and a phase difference of the output current and the output voltage, and a determination that the power reception device is executing the suppression control when a coordinate position of a set of the amplitude ratio and the phase difference is not included in a predetermined range.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a control device, a control method, and a program for control of a power transmission device that wirelessly transmits power to a power receiving device, and also to a contactless power transmission system that wirelessly transmits power from a power transmission device to a power receiving device. [Background technology]

[0002] In recent years, a contactless power transfer system that transfers power from a power transmitting device to a power receiving device in a contactless manner has been proposed. In order to protect the power receiving device and the battery to be charged from overvoltage caused by an excessively large received power, a technology for suppressing the received power by switching control has been devised for the contactless power transfer system.

[0003] Patent document 1 discloses a wireless power receiving device including a receiving side resonant circuit having a receiving coil that receives power wirelessly (contactlessly) from the transmitting side and a receiving side resonant capacitor connected to the receiving coil, a rectifier circuit that rectifies the power received by the receiving coil and outputs it to a load, a receiving side voltage detection unit that detects the output voltage of the rectifier circuit, a switching element connected between the output unit of the receiving side resonant circuit and the output unit of the rectifier circuit and a short circuit having a rectifier element inserted between the output unit of the receiving side resonant circuit and the switching element, and a control circuit that operates the switching element when the output voltage value detected by the receiving side voltage detection unit exceeds a preset reference voltage value. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6361818 Summary of the Invention [Problem to be solved by the invention]

[0005] When switching control is performed for a long period of time, switching loss increases and power efficiency decreases. In addition, heat loss in the switching device increases, which increases costs due to the need for a larger cooling device. For this reason, it is desirable to reduce the period of switching control for suppressing the received power. In order to reduce the period of switching control in the power receiving device, it is possible to control the transmitted power of the power transmitting device according to the state of the power receiving device. However, depending on the environment in which the contactless power transmission system is applied, it is difficult for the power transmitting device to constantly communicate with the power receiving device, and there is a risk that the power transmitting device cannot properly acquire the state of the power receiving device.

[0006] In view of the above-mentioned problems, one object of the present disclosure is to provide a technique capable of controlling transmission power according to the state of a power receiving device, without requiring constant communication with the power receiving device. [Means for solving the problem]

[0007] The first disclosure relates to a control device for a power transmitting device that transmits power to a power receiving device in a wireless manner. Here, the power receiving device is configured to perform suppression control of received power by switching control at a predetermined opportunity.

[0008] The control device of the first disclosure is configured to execute a determination process for determining whether or not the power receiving device is performing suppression control based on the output current and output voltage of an inverter provided in the power transmitting device, and a power control process for controlling the transmission power of the power transmitting device based on the result of the determination process.

[0009] The second disclosure relates to a control device having the following characteristics in addition to the control device according to the first disclosure.

[0010] The determination process includes calculating the amplitude ratio and phase difference between the output current and output voltage, and determining that the power receiving device is performing suppression control when the coordinate position of the pair of amplitude ratio and phase difference is not included in a predetermined range.

[0011] The third disclosure relates to a control device further having the following features in addition to the control device according to the second disclosure.

[0012] The control device according to the third disclosure is configured to further execute a process of acquiring specification information and identification information for identifying a power receiving device that is predicted to be a target of power transmission, and a process of identifying a power receiving device to be a target of power transmission based on the identification information before starting power transmission. The determination process further includes determining a predetermined range based on the specification information for the identified power receiving device.

[0013] The fourth disclosure relates to a control device further having the following features in addition to the control devices according to the first to third disclosures.

[0014] The power control process includes controlling the power transmission to be reduced when it is determined that the power receiving device is performing the suppression control.

[0015] The fifth disclosure relates to a control method for a power transmitting device that transmits power to a power receiving device in a wireless manner, wherein the power receiving device is configured to perform suppression control of received power by switching control at a predetermined opportunity.

[0016] The control method of the fifth disclosure includes determining whether or not the power receiving device is performing suppression control based on the output current and output voltage of an inverter provided in the power transmitting device, and controlling the transmission power of the power transmitting device based on the result of the determination of whether or not the power receiving device is performing suppression control.

[0017] The sixth disclosure relates to a control method further having the following characteristics in addition to the control method according to the fifth disclosure.

[0018] Determining whether the power receiving device is performing suppression control includes calculating the amplitude ratio and phase difference of the output current and output voltage, and determining that the power receiving device is performing suppression control when the coordinate position of the pair of the amplitude ratio and phase difference is not included in a predetermined range.

[0019] The seventh disclosure relates to a program for controlling a power transmitting device that wirelessly transmits power to a power receiving device, wherein the power receiving device is configured to implement suppression control of received power by switching control at a predetermined opportunity.

[0020] The program relating to the seventh disclosure is configured to cause a computer to execute a determination process for determining whether or not the power receiving device is performing suppression control based on the output current and output voltage of an inverter provided in the power transmitting device, and a process for controlling the transmission power of the power transmitting device based on the result of the determination process.

[0021] The eighth disclosure relates to a program further having the following characteristics with respect to the program according to the seventh disclosure.

[0022] The determination process includes calculating the amplitude ratio and phase difference between the output current and output voltage, and determining that the power receiving device is performing suppression control when the coordinate position of the pair of amplitude ratio and phase difference is not included in a predetermined range.

[0023] The ninth disclosure relates to a contactless power transfer system that transfers power from a power transmitting device to a power receiving device in a contactless manner.

[0024] A non-contact power transmission system according to a ninth disclosure includes a power receiving device configured to perform suppression control of received power by switching control at a predetermined opportunity, a power transmitting device that transmits power to the power receiving device in a non-contact manner, at least one processor, and a memory coupled to the at least one processor and storing a plurality of executable instructions. The plurality of executable instructions are configured to cause the at least one processor to execute a determination process of determining whether or not the power receiving device is performing suppression control based on an output current and an output voltage of an inverter included in the power transmitting device, and a process of suppressing the transmission power of the power transmitting device based on a result of the determination process.

[0025] The tenth disclosure relates to a contactless power transfer system further having the following features in addition to the contactless power transfer system according to the ninth disclosure.

[0026] The determination process includes calculating the amplitude ratio and phase difference between the output current and output voltage, and determining that the power receiving device is performing suppression control when the coordinate position of the pair of amplitude ratio and phase difference is not included in a predetermined range. Effect of the Invention

[0027] According to the present disclosure, it is determined whether or not the power receiving device is performing the suppression control based on the output current and output voltage of an inverter provided in the power transmitting device. Then, the transmission power of the power transmitting device is controlled based on the result of the determination. This makes it possible to determine whether or not the power receiving device is performing the suppression control and control the transmission power without the need for constant communication with the power receiving device. In addition, it is possible to reduce the period during which the power receiving device performs the suppression control. Furthermore, it is possible to suppress the decrease in power efficiency and the heat loss associated with switching control, thereby reducing costs and making the power receiving device smaller. [Brief description of the drawings]

[0028] [Figure 1] 1 is a circuit diagram showing a configuration example of a contactless power transfer system according to an embodiment of the present invention. [Diagram 2] 1 is a graph showing an example of a voltage applied to an active rectifier when PWM control is adopted as switching control. [Diagram 3] 1 is a conceptual diagram showing a case where a contactless power transfer system is applied to a charging system for charging a battery provided in a vehicle while the vehicle is traveling. [Figure 4] 4 is a graph showing an output current and an output voltage of an inverter. [Diagram 5] 11 is a graph showing an example of a two-dimensional plot of a set of gain and phase difference when the duty is increased by PWM control. [Figure 6]4 is a conceptual diagram showing an example of when the power transmission control device executes a process for determining a predetermined range in the case shown in FIG. 3. FIG. [Figure 7] 4 is a flowchart showing a process executed by a power transmission control device according to the present embodiment. [Figure 8] 1 is a block diagram showing a schematic configuration of a power transmission control device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. However, when the number, quantity, amount, range, etc. of each element is mentioned in the embodiments shown below, the idea of ​​the present disclosure is not limited to the mentioned number unless it is specifically stated or the number is clearly specified in principle. Furthermore, the configurations etc. described in the embodiments shown below are not necessarily essential to the idea of ​​the present disclosure unless it is specifically stated or the number is clearly specified in principle. In addition, the same reference numerals are attached to the same or corresponding parts in each drawing, and the duplicated explanation is appropriately simplified or omitted.

[0030] 1. Contactless power transfer system This embodiment relates to a contactless power transfer system that transfers power from a power transmitting device to a power receiving device in a contactless manner. Fig. 1 is a circuit diagram showing a configuration example of the contactless power transfer system according to this embodiment. Fig. 1 shows a case where the contactless power transfer system is applied to a charging system that charges a battery 2 with power supplied by a DC power source 1. That is, the DC power source 1 supplies power to a power transmitting device 110, and the power is transmitted from the power transmitting device 110 to a power receiving device 210 in a contactless manner. Then, the battery 2 is charged with the power received by the power receiving device 210.

[0031] The DC power source 1 and the power transmitting device 110 are typically placed on the ground, a floor, a wall, or the like. The power receiving device 210 and the battery 2 are typically mounted on a mobile object to be charged, such as a mobile terminal or a vehicle. The battery 2 is typically a rechargeable secondary battery, such as a lithium ion battery or a nickel metal hydride battery.

[0032] 1, a power transmitting coil 116 included in a power transmitting device 110 and a power receiving coil 216 included in a power receiving device 210 are magnetically resonated with each other, so that power is transmitted from the power transmitting coil 116 to the power receiving coil 216. That is, power is transmitted by a magnetic field resonance method.

[0033] The power transmitting device 110 includes a smoothing capacitor 111, an inverter 112, an immittance filter 114, and a power transmitting circuit 115. Here, the inverter 112, the immittance filter 114, and the power transmitting circuit 115 are configured to be connected in cascade.

[0034] The inverter 112 converts the DC power into AC power of a predetermined frequency and outputs the AC power. The output power of the inverter 112 is supplied to the power transmission circuit 115 via the immittance filter 114.

[0035] The inverter 112 is configured with a single-phase full-bridge circuit including a switching device 113. The inverter 112 is also connected to the power transmission control device 100. The power transmission control device 100 is a control device that performs switching control of the switching device 113 based on information acquired from a detection device 120 (e.g., an ammeter or a voltmeter). This controls the frequency and magnitude of the output power of the inverter 112. In turn, the transmission power of the power transmission device 110 is controlled. In particular, the frequency of the output power of the inverter 112 is adjusted to be equal to the resonant frequency of the power transmission circuit 115. In this sense, the resonant frequency of the power transmission circuit 115 can also be called the "drive frequency." Note that the information acquired by the power transmission device 110 from the detection device 120 includes at least the output current and output voltage of the inverter 112.

[0036] The immittance filter 114 reduces electromagnetic noise in the output power of the inverter 112. The immittance filter 114 is composed of a coil and a capacitor, and functions as a low-pass filter. It also adjusts the impedance of the power transmitting device 110.

[0037] The power transmitting circuit 115 is a resonant circuit configured with a power transmitting coil 116 and a resonant capacitor 117. When power of a resonant frequency is supplied from the inverter 112 to the power transmitting circuit 115, the power transmitting coil 116 magnetically resonates with the power receiving coil 216. As a result, power is transmitted from the power transmitting coil 116 to the power receiving coil 216.

[0038] The power receiving device 210 includes a smoothing capacitor 211, an active rectifier 212, an immittance filter 214, and a power receiving circuit 215. Here, the active rectifier 212, the immittance filter 214, and the power receiving circuit 215 are each configured to be connected in cascade.

[0039] The power receiving circuit 215 is a resonant circuit configured with a power receiving coil 216 and a resonant capacitor 217. The resonant frequency of the power receiving circuit 215 is configured to be equal to the resonant frequency of the power transmitting circuit 115. The power receiving coil 216 resonates with the power transmitting coil 116 in a magnetic field, and receives the power transmitted from the power transmitting coil 116.

[0040] The immittance filter 214 reduces electromagnetic noise in the power received by the power receiving circuit 215. The immittance filter 214 is made up of a coil and a capacitor, and functions as a low-pass filter. It also adjusts the impedance of the power receiving device 210.

[0041] The active rectifier 212 converts the power received by the power receiving circuit 215 into DC power and outputs it. The output power of the active rectifier 212 is supplied to the battery 2 via the smoothing capacitor 211. In other words, the output power of the active rectifier 212 becomes the received power of the power receiving device 210.

[0042] The active rectifier 212 is configured by a single-phase full-wave rectifier circuit including a switching device 213. The active rectifier 212 is also connected to the power receiving control device 200. The power receiving control device 200 is a control device that performs switching control of the switching device 213 based on information acquired from the detection device 220. This controls the output power of the active rectifier 212 (the received power of the power receiving device 210).

[0043] More specifically, the power receiving control device 200 temporarily forms a short circuit in the active rectifier 212 by switching the switching device 213 on and off. When the short circuit is formed, almost no output power from the active rectifier 212 is supplied to the battery 2. Therefore, by temporarily forming a short circuit through switching control, it is possible to suppress the output power of the active rectifier 212 (the received power of the power receiving device 210). In other words, the power receiving control device 200 performs "suppression control" of the received power through switching control. The fact that suppression control is being performed can also be said to mean that the power receiving device 210 is in a "short circuit mode" since a short circuit is temporarily formed.

[0044] The suppression control is typically performed to prevent the received power from exceeding an upper limit determined by the ratings of the power receiving device 210 and the battery 2, for the purpose of protecting the power receiving device 210 and the battery 2. In this case, the suppression control is performed, for example, when the received power exceeds the upper limit or is predicted to exceed the upper limit.

[0045] In particular, the power receiving control device 200 can implement suppression control by adopting PWM control as the switching control. In this case, the duty of the PWM control corresponds to the period during which a short circuit is formed. FIG. 2 is a graph showing an example of the voltage applied to the active rectifier 212 when PWM control is adopted as the switching control. FIG. 2 shows a graph (dashed line) when suppression control is not implemented, and a graph (solid line) when suppression control using PWM control is implemented. In this way, in suppression control using PWM control, by increasing the duty, the period during which a short circuit is formed increases, and the suppression of the received power can be further strengthened.

[0046] As described above, the contactless power transfer system according to the present embodiment is configured. In the contactless power transfer system shown in Fig. 1, the power transmitting device 110 is supplied with power from a DC power source 1, but may be configured to be supplied with power from an AC power source. In this case, a converter is provided at the input stage of the power transmitting device 110, so that the system can be configured in the same way as in Fig. 1.

[0047] The contactless power transmission system according to the present embodiment may include a plurality of power transmission devices 110 or a plurality of power receiving devices 210. For example, a case where the contactless power transmission system is applied to a charging system in which a battery 2 provided in a vehicle is charged while the vehicle is traveling is considered. FIG. 3 shows an example of a case where the contactless power transmission system is applied to a charging system in which a vehicle 3 is charged while traveling. In the example shown in FIG. 3, when the vehicle 3 passes a plurality of power transmission devices 110 arranged in a line on a traveling path, the power receiving device 210 provided in the vehicle 3 receives power in a contactless manner, thereby charging the battery 2. Although two power transmission devices 110 are illustrated in FIG. 3, more power transmission devices 110 may be arranged over a longer distance. In this case, considering that a plurality of similar vehicles 3 may exist, the contactless power transmission system includes a plurality of power receiving devices 210.

[0048] However, if the power receiving device 210 performs the suppression control for a long period of time, the switching loss associated with the switching control increases, and the power efficiency decreases. In addition, the heat loss of the switching device increases, which increases the cost due to the need for a larger cooling device, etc. For this reason, it is desirable to reduce the period of the suppression control in the power receiving device 210.

[0049] In order to reduce the period of suppression control in the power receiving device 210, it is conceivable to control the transmission power of the power transmitting device 110 according to the state of the power receiving device 210. However, depending on the environment in which the contactless power transmission system is applied, it may be difficult for the power transmitting device 110 to constantly communicate with the power receiving device 210, and there is a risk that the power transmitting device 110 may not be able to appropriately acquire the state of the power receiving device 210. For example, in the example shown in Fig. 3, it is assumed that the period during which one power transmitting device 110 transmits power is very short, and therefore a delay in control when acquiring the state of the power receiving device 210 through communication cannot be ignored.

[0050] In response to this, the inventors of the present disclosure have found that it is possible to determine whether or not the power receiving device 210 is performing suppression control from the characteristics of the output current and output voltage of the inverter 112. In the contactless power transfer system according to this embodiment, this characteristic is utilized to provide a feature in the process executed by the power transmission control device 100. The characteristics of the output current and output voltage of the inverter 112 and the features of the power transmission control device 100 according to this embodiment will be described below.

[0051] 2. Inverter output current and output voltage characteristics As shown in Fig. 4, the output current and output voltage of the inverter 112 have different amplitudes and phases depending on the impedance of the power transmitting device 110 and the power receiving device 210. For this reason, an amplitude ratio and a phase difference can be given to the output current and output voltage of the inverter 112. However, in the following, the amplitude ratio is defined as the ratio of the amplitude of the output voltage to the amplitude of the output current (amplitude of the output voltage / amplitude of the output current). In this case, the amplitude ratio can also be called "gain". In other words, the unit of gain is Ω.

[0052] The inventors of the present disclosure noticed that when the coupling coefficient between the transmitting coil 116 and the receiving coil 216 is kept constant (the relative positions of the power transmitting device 110 and the power receiving device 210 are kept constant) and the duty of the PWM control in the power receiving device 210 is increased, a two-dimensional plot of the combination of gain and phase difference forms a specific curve.

[0053] FIG. 5 shows an example of a two-dimensional plot of a set of gain and phase difference when the duty is increased for three different coupling coefficients (large (solid line), medium (dashed line), and small (dotted and dashed line)). As shown in FIG. 5, the two-dimensional plot of the set of gain and phase difference when the duty is increased draws a specific curve. This curve is determined from circuit information of the power transmitting device 110 and the power receiving device 210. Here, examples of the circuit information include the circuit configuration, driving frequency, inductance of the power transmitting coil 116 and the power receiving coil 216, resistance value, capacitor capacity, power supply voltage, etc. However, if the coupling coefficient is changed, a different curve will be drawn. In a contactless power transfer system, it is generally assumed that the coupling coefficient changes each time.

[0054] On the other hand, the inventors of the present disclosure have found that the predetermined range 10 can be determined so as to connect the points where the duty is zero (the points when suppression control is not performed, shown by triangle marks in FIG. 5), which are the starting points of each curve. Here, the predetermined range 10 may be determined in consideration of the range of measurement error. The predetermined range 10 does not depend on the coupling coefficient because of the way in which it is determined. In addition, since a specific curve drawn by a two-dimensional plot of a pair of gain and phase difference is determined from circuit information of the power transmitting device 110 and the power receiving device 210, the predetermined range 10 can be uniquely determined for the pair of the power transmitting device 110 and the power receiving device 210. The predetermined range 10 can be managed in advance as map information as shown in FIG. 5, for example.

[0055] Once the predetermined range 10 is determined, it can be determined whether or not the power receiving device 210 is performing the suppression control, based on the output current and output voltage of the inverter 112. In other words, when the coordinate position of the pair of gain and phase difference is not included in the predetermined range 10, it can be determined that the power receiving device 210 is performing the suppression control.

[0056] The power transmission control device 100 according to the present embodiment uses the above characteristics to execute a process (determination process) for determining whether or not the power receiving device 210 is performing the power reduction control based on the output current and output voltage of the inverter 112. The output current and output voltage of the inverter 112 can be acquired by the power transmitting device 110. Therefore, without the need for constant communication with the power receiving device 210, it is possible to determine whether or not the power receiving device 210 is performing the power reduction control and control the transmission power.

[0057] Incidentally, when a contactless power transfer system includes a plurality of power transmitting devices 110 or a plurality of power receiving devices 210, it is assumed that the predetermined range 10 differs depending on the pair of the power transmitting device 110 and the power receiving device 210. For this reason, the power transmission control device 100 according to the present embodiment may be configured to execute the following process.

[0058] First, the power transmission control device 100 executes a process of acquiring specification information and information (identification information) for identifying the power receiving device 210 for the power receiving device 210 that is predicted to be a target of power transmission. Here, the specification information includes circuit information of the power receiving device 210. The identification information is, for example, ID information of the power receiving device 210. Alternatively, it is ID information of a mobile object that mounts the power receiving device 210. The power transmission control device 100 manages the acquired specification information and identification information in association with each other. Note that the information may be acquired at a location where the power transmitting device 110 and the power receiving device 210 are separated from each other by, for example, wide area communication or the like.

[0059] Next, the power transmission control device 100 executes a process of identifying the power receiving device 210 to be the target of power transmission based on the identification information acquired in advance before starting power transmission. For example, when any of the power receiving devices 210 is in the vicinity of the power transmitting device 110, ID information is acquired from the power receiving device 210, and the power receiving device 210 to be the target of power transmission is identified by comparing the ID information with the ID information acquired in advance. In this case, the ID information may be acquired from the power receiving device 210 by short range communication, for example. By identifying the power receiving device 210 in this manner, it is possible to refer to the specification information of the power receiving device 210 to be the target of power transmission simply by communicating the identification information.

[0060] Then, in the determination process, the power transmission control device 100 determines the predetermined range 10 based on the specification information of the identified power receiving device 210. This can be done, for example, by referring to the corresponding specification information from the identification information of the identified power receiving device 210 and calculating a two-dimensional plot of a set of gain and phase difference from the specification information of the power transmission device 110 and the specification information of the power receiving device 210.

[0061] By executing the process in this manner, the power transmission control device 100 can manage the predetermined range 10 for the power receiving device 210 to which power is to be transmitted before starting power transmission, even when the contactless power transmission system includes a plurality of power transmitting devices 110 or a plurality of power receiving devices 210. Furthermore, it is possible to determine whether the power receiving device 210 is performing suppression control and control the transmission power, without the need for constant communication with the power receiving device 210.

[0062] FIG. 6 is a conceptual diagram showing an example of the power transmission control device 100 performing the above-described process in the case shown in FIG. 3. In the example shown in FIG. 6, the power transmission control device 100 performs wide-area communication with a vehicle 3 (for example, predicted from a driving plan of the vehicle 3) that is predicted to travel on a road on which a plurality of power transmission devices 110 are arranged in a row, and acquires a vehicle ID of the vehicle 3 as identification information and circuit information of the power receiving device 210 provided in the vehicle 3 as specification information. Here, examples of wide-area communication include LTE and 4G. Next, when the vehicle 3 approaches the power transmission device 110, the power transmission control device 100 performs short-range communication with the vehicle 3 and acquires the vehicle ID. Thereby, the power transmission control device 100 can specify the power receiving device 210 to be the target of power transmission and acquire circuit information of the power receiving device 210 to be the target of power transmission. Here, examples of short-range communication include RF-ID. Then, the power transmission control device 100 determines a predetermined range 10 for the power receiving device 210 to which power is to be transmitted, and starts power transmission.

[0063] 3. Processing performed by the power transmission control device Hereinafter, the process executed by the power transmission control device 100 according to the present embodiment will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the process executed by the power transmission control device 100 according to the present embodiment. The flowchart shown in Fig. 7 is repeatedly executed for the target power receiving device 210 at predetermined processing intervals. In the following description, it is assumed that a predetermined range 10 for the power receiving device 210 to which power is transmitted is determined and managed in advance.

[0064] In step S100 , the power transmission control device 100 acquires the output current and output voltage of the inverter 112 from the detection device 120 .

[0065] After step S100, the process proceeds to step S110.

[0066] In step S110, the power transmission control device 100 executes a filtering process on the output current and output voltage acquired in step S100. This extracts fundamental wave components of the output current and output voltage. Note that the filtering process may be performed using a known suitable technique.

[0067] After step S110, the process proceeds to step S120.

[0068] In step S120, the power transmission control device 100 calculates the gain and phase difference of the output current and output voltage.

[0069] After step S120, the process proceeds to step S130.

[0070] In step S130 (determination process), the power transmission control device 100 determines whether or not the coordinate position of the pair of gain and phase difference calculated in step S120 is included in a predetermined range 10. That is, it determines whether or not the power receiving device 210 is performing suppression control. The power transmission control device 100 executes a process (power control process) for controlling the transmission power of the power transmitting device 110 based on the result of the determination in step S130 (step S140 or step S150).

[0071] If the coordinate position of the pair of gain and phase difference is included in the predetermined range 10 (step S130; Yes), that is, if it is determined that the power receiving device 210 is not performing suppression control, the power transmission control device 100 performs switching control of the inverter 112 to maintain or increase the transmitted power (step S140). If the coordinate position of the pair of gain and phase difference is not included in the predetermined range 10 (step S130; No), that is, if it is determined that the power receiving device 210 is performing suppression control, the power transmission control device 100 performs switching control of the inverter 112 to reduce the transmitted power (step S150).

[0072] In this manner, the processing is executed by the power transmission control device 100. In addition, in this manner, the power transmission control device 100 according to the present embodiment realizes a control method for the power transmission device 110. Furthermore, the control method according to the present embodiment can also be applied to a program for controlling the power transmission device 110.

[0073] 4. Configuration of power transmission control device Hereinafter, the configuration of the power transmission control device 100 according to this embodiment will be described with reference to FIG. 8. FIG. 8 is a block diagram showing a schematic configuration of the power transmission control device 100 according to this embodiment. The power transmission control device 100 is a computer including a memory 101, a processor 105, and a communication device 106. The memory 101 is coupled to the processor 105 and stores a plurality of executable instructions 104 and various data 102 required for executing processing. Here, the instructions 104 are provided by a program 103. In this sense, the memory 101 can also be called a "program memory." In addition, map information that provides a predetermined range 10 is exemplified as the data 102 stored in the memory 101.

[0074] The communication device 106 is a device that transmits and receives information to and from devices external to the power transmission control device 100. For example, the communication device 106 is a device that performs wide-area communication or short-range communication with the vehicle 3. Examples of information received by the communication device 106 include the output current and output voltage of the inverter 112, and specification information and identification information of the power receiving device 210. Furthermore, map information that gives a predetermined range 10 may be acquired via the communication device 106. The information received by the communication device 106 is stored in the memory 101 as data 102.

[0075] The instructions 104 are configured to cause the processor 105 to execute the process shown in Fig. 7. That is, the processor 105 operates in accordance with the instructions 104 to execute the process shown in Fig. 7 based on the data 102.

[0076] 5.Effects As described above, according to this embodiment, it is determined whether the power receiving device 210 is performing suppression control based on the output current and output voltage of the inverter 112. Then, the transmission power of the power transmitting device 110 is controlled based on the result of the determination. This makes it possible to reduce the period during which the power receiving device 210 performs suppression control without requiring constant communication with the power receiving device 210. In turn, it is possible to suppress the decrease in power efficiency and the heat loss associated with switching control. Furthermore, it is possible to reduce costs and make the power receiving device 210 smaller.

[0077] In this embodiment, the magnetic field resonance type contactless power transfer system has been described, but the present invention can also be applied to other types of contactless power transfer systems such as an electromagnetic induction type. [Explanation of symbols]

[0078] 1 DC power supply 10. Prescribed range 100 Power transmission control device 101 Memory 103 Programs 104 Instructions 105 processors 110 Power transmission equipment 116 Transmission coil 200 Power receiving control device 210 Power receiving device 216 Receiving coil

Claims

1. A control device for a power transmission device that transmits power to a power receiving device in a non-contact manner, The power receiving device is configured to perform a suppression control of the received power by switching control at a predetermined opportunity, The control device includes: a determination process for determining whether or not the power receiving device is performing the suppression control based on an output current and an output voltage of an inverter included in the power transmitting device; a power control process for controlling the transmission power of the power transmitting device based on a result of the determination process; It is configured to run A control device comprising:

2. The control device according to claim 1 , The determination process includes: Calculating an amplitude ratio and a phase difference between the output current and the output voltage; determining that the power receiving device is performing the suppression control when a coordinate position of the pair of the amplitude ratio and the phase difference is not included in a predetermined range; Includes A control device comprising:

3. The control device according to claim 2, A process of acquiring specification information and identification information for identifying the power receiving device, the power receiving device being predicted to be a target of power transmission; A process of identifying the power receiving device to which power is to be transmitted based on the identification information before starting power transmission; and further configured to execute: The determination process further includes determining the predetermined range based on the specification information about the identified power receiving device. A control device comprising:

4. The control device according to any one of claims 1 to 3, The power control process includes controlling the power transmission to be reduced when it is determined that the power receiving device is performing the suppression control. A control device comprising:

5. A control method for a power transmitting device that wirelessly transmits power to a power receiving device, comprising: The power receiving device is configured to perform a suppression control of the received power by switching control at a predetermined opportunity, The control method includes: determining whether the power receiving device is performing the suppression control based on an output current and an output voltage of an inverter included in the power transmitting device; Controlling the transmission power of the power transmitting device based on a result of determining whether the power receiving device is performing the suppression control; Includes A control method comprising:

6. 6. The control method according to claim 5, Determining whether the power receiving device is performing the suppression control Calculating an amplitude ratio and a phase difference between the output current and the output voltage; determining that the power receiving device is performing the suppression control when a coordinate position of the pair of the amplitude ratio and the phase difference is not included in a predetermined range; Includes A control method comprising:

7. A program for controlling a power transmitting device that transmits power to a power receiving device in a wireless manner, The power receiving device is configured to perform a suppression control of the received power by switching control at a predetermined opportunity, The program is a determination process for determining whether or not the power receiving device is performing the suppression control based on an output current and an output voltage of an inverter included in the power transmitting device; A process of controlling the transmission power of the power transmitting device based on a result of the determination process; configured to cause a computer to execute A program characterized by:

8. The program according to claim 7, The determination process includes: Calculating an amplitude ratio and a phase difference between the output current and the output voltage; determining that the power receiving device is performing the suppression control when a coordinate position of the pair of the amplitude ratio and the phase difference is not included in a predetermined range; Includes A program characterized by:

9. A power receiving device configured to perform suppression control of received power by switching control at a predetermined opportunity; A power transmitting device that transmits electric power to the power receiving device in a wireless manner; At least one processor; a memory coupled to the at least one processor and storing a plurality of executable instructions; Including, The plurality of executable instructions may be configured to cause the at least one processor to: a determination process for determining whether or not the power receiving device is performing the suppression control based on an output current and an output voltage of an inverter included in the power transmitting device; A process of controlling the transmission power of the power transmitting device based on a result of the determination process; It is configured to run A non-contact power transmission system comprising:

10. The contactless power transfer system according to claim 9, The determination process includes: Calculating an amplitude ratio and a phase difference between the output current and the output voltage; determining that the power receiving device is performing the suppression control when a coordinate position of the pair of the amplitude ratio and the phase difference is not included in a predetermined range; Includes A non-contact power transmission system comprising:

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