JP2014193029A - Power transmission apparatus, power reception apparatus, and non-contact power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission apparatus, power reception apparatus, and non-contact power transmission device, capable of restraining generation of unnecessary power loss while suitably adjusting impedance.SOLUTION: A non-contact power transmission device 10 includes: a high-frequency power supply 12 that can supply high-frequency power; a power transmission device 13 that is supplied with high-frequency power; a power reception device 23 that can receive high-frequency power from the power transmission device 13 in a non-contact manner; and a load 22 that is supplied with high-frequency power received by the power receiving device 23. Between the high-frequency power supply 12 and the load 22, there are provided a primary impedance converter group G1 that performs impedance conversion and a series connection element 40 comprised of a variable resistor 41 and a switching element 42 apart from the primary impedance converter group G1.

Description

  The present invention relates to a power transmission device, a power reception device, and a non-contact power transmission device.

  As a non-contact power transmission device that does not use a power cord or a power transmission cable, for example, a power transmission device having a primary coil to which AC power is supplied, and a secondary coil that can receive AC power in a non-contact manner from the primary coil There is known a device including a power receiving device having (see, for example, Patent Document 1). In such a non-contact power transmission device, for example, AC power is transmitted from the power transmitting device to the power receiving device by magnetic resonance between the primary coil and the secondary coil.

JP 2009-106136 A

  Here, in the non-contact power transmission apparatus as described above, for example, an impedance converter may be provided in order to improve transmission efficiency. In this case, a deviation may occur between the impedance converted by the impedance converter and the target impedance due to fluctuations in the relative positions of the primary coil and the secondary coil. For this reason, adjustment of impedance may be required. However, it is not preferable that unnecessary power loss occurs due to the provision of the impedance adjustment.

  The situation described above is not limited to a non-contact power transmission device as long as it has an impedance conversion unit, and is a non-contact power transmission device that can transmit AC power to a power receiving device or a non-contact AC power from a power transmission device. This is also common to power receiving devices that can receive power.

  The present invention has been made in view of the above-described circumstances, and provides a power transmission device, a power reception device, and a non-contact power transmission device that can suppress unnecessary power loss while suitably adjusting impedance. With the goal.

  A power transmission device that achieves the above-described object has a primary coil to which AC power is supplied, can transmit the AC power in a contactless manner with respect to a power receiving device having a secondary coil, and the primary side An impedance conversion unit that is provided on the input side of the coil and performs impedance conversion, a resistor provided separately from the impedance conversion unit, the resistor and the impedance conversion unit are electrically connected, and the AC power is supplied to the resistor and the impedance The conduction state supplied to the primary coil via the impedance converter, or the resistance and the impedance converter are interrupted, and the AC power is supplied to the primary coil via the impedance converter. And a switching element that switches to a cut-off state.

  According to such a configuration, when the switching element is in a conductive state, the resistor and the impedance conversion unit cooperate to perform impedance conversion. On the other hand, when the switching element is in the cut-off state, AC power is not supplied to the resistor. Thereby, when adjustment of impedance using a resistor is necessary, the switching element is turned on, while when adjustment of impedance using a resistor is not required, the switching element is turned off, It is possible to suppress unnecessary power loss while suitably adjusting the impedance.

  In the power transmission device, the resistor may be a variable resistor having a variable resistance value. According to such a configuration, since the resistance value is variable, the adjustable range of the impedance is wide as compared with the case where the resistance value is fixed. Thereby, the impedance can be adjusted more suitably by variably controlling the resistance value of the variable resistor.

  The power transmission device may include a plurality of series connection bodies in which the resistor and the switching element are connected in series, and the plurality of series connection bodies may be connected in parallel to each other. According to such a configuration, by performing switching control of the switching element, the combined resistance value by each series connection body becomes variable. Thereby, a plurality of types of resistance values can be realized. Therefore, the impedance can be adjusted more suitably by performing switching control of the switching element.

  For the power transmission device, the impedance of the impedance converter is variable, and the switching element is in the cut-off state when variable control of the impedance of the impedance converter is performed, and the impedance of the impedance converter When the impedance is further adjusted after the variable control, it is preferable to switch from the cut-off state to the conduction state. According to such a configuration, when the variable control of the impedance of the impedance converter is performed, the switching element is in a cut-off state, and when the impedance is further adjusted after the variable control of the impedance of the impedance converter The switching element is switched from the cut-off state to the conductive state. Thereby, before adjusting the impedance using the resistor, the power loss due to the resistor can be avoided as much as possible by adjusting the impedance using the impedance converter. Further, when the variable control of the impedance of the impedance converter cannot cope, the impedance can be further adjusted by bringing the switching element into a conductive state.

  “When the impedance is further adjusted after the impedance control of the impedance converter”, for example, the power transmission device includes an AC power source capable of supplying AC power to the primary coil, and the impedance converter includes an AC In the configuration in which the impedance conversion is performed so that the impedance of the output end of the power source approaches a predetermined primary side specific impedance, the impedance of the output end of the AC power source is not changed even if the impedance of the impedance conversion unit is varied. This is the case when it is outside the allowable range.

  A power receiving device that achieves the above-described object can receive the AC power in a contactless manner from a power transmission device having a primary coil to which AC power is supplied, and can receive the AC power in a contactless manner from the primary coil. A possible secondary coil, a load, an impedance converter provided between the secondary coil and the load, for impedance conversion, a resistor provided separately from the impedance converter, and the resistor The impedance converter is electrically connected, and the power is transmitted from the secondary coil to the load via the resistor and the impedance converter, or the resistor and the impedance converter are interrupted. Switching to a cut-off state in which power is transmitted from the secondary coil to the load via the impedance converter. Characterized in that it comprises a child, a.

  According to such a configuration, when the switching element is in a conductive state, the resistor and the impedance conversion unit cooperate to perform impedance conversion. On the other hand, when the switching element is in the cut-off state, AC power is not supplied to the resistor. Thereby, when adjustment of impedance using a resistor is necessary, the switching element is turned on, while when adjustment of impedance using a resistor is not required, the switching element is turned off, It is possible to suppress unnecessary power loss while suitably adjusting the impedance.

  A non-contact power transmission device that achieves the above object is capable of receiving the AC power in a non-contact manner from an AC power supply capable of supplying AC power, a primary coil supplied with the AC power, and the primary coil. A secondary coil, a load, an impedance conversion unit that performs impedance conversion provided between the AC power source and the load, a resistor that is provided separately from the impedance conversion unit, the resistance and the impedance A conduction state in which the converter is connected and power is transmitted through the resistor and the impedance converter, or the resistor and the impedance converter are disconnected, and power is transmitted through the impedance converter. And a switching element that switches to a cut-off state.

  According to such a configuration, when the switching element is in a conductive state, the resistor and the impedance conversion unit cooperate to perform impedance conversion. On the other hand, when the switching element is in the cut-off state, AC power is not supplied to the resistor. Thereby, when adjustment of impedance using a resistor is necessary, the switching element is turned on, while when adjustment of impedance using a resistor is not required, the switching element is turned off, It is possible to suppress unnecessary power loss while suitably adjusting the impedance.

  In addition, you may apply the structure limited in the said power transmission apparatus with respect to a power receiving apparatus and a non-contact electric power transmission apparatus.

  According to the present invention, it is possible to suppress unnecessary power loss while suitably adjusting the impedance.

The circuit diagram which shows the electrical constitution of the non-contact electric power transmission apparatus of 1st Embodiment. The flowchart which shows the primary side adjustment process performed with a power supply side controller. The circuit diagram which shows the electrical constitution of the non-contact electric power transmission apparatus of 2nd Embodiment. The flowchart which shows the secondary side adjustment process performed with a vehicle side controller. The circuit diagram of the ground side apparatus of another example. The circuit diagram of the ground side apparatus of another example.

(First embodiment)
Hereinafter, a first embodiment in which a power transmission device (power transmission device), a power reception device (power reception device), and a non-contact power transmission device (non-contact power transmission system) are applied to a vehicle will be described.

  As shown in FIG. 1, the non-contact power transmission apparatus 10 includes a ground side device 11 provided on the ground and a vehicle side device 21 mounted on the vehicle. The ground side device 11 corresponds to a power transmission device (primary side device), and the vehicle side device 21 corresponds to a power receiving device (secondary side device).

  The ground side device 11 includes a high frequency power source 12 (AC power source) capable of supplying high frequency power (AC power) having a predetermined frequency. The high-frequency power source 12 is configured to convert system power supplied from a system power source as infrastructure into high-frequency power and supply the converted high-frequency power. The high frequency power supply 12 can supply a plurality of types of high frequency power having different power values.

  The high-frequency power supplied from the high-frequency power source 12 is transmitted to the vehicle-side device 21 in a non-contact manner and supplied to a load 22 provided in the vehicle-side device 21. Specifically, the non-contact power transmission device 10 is provided in the vehicle-side device 21 and the power transmitter 13 provided in the ground-side device 11 as a device that performs power transmission between the ground-side device 11 and the vehicle-side device 21. The power receiver 23 is provided.

  The power transmitter 13 and the power receiver 23 have the same configuration, and both are configured to be capable of magnetic field resonance. Specifically, the power transmitter 13 includes a resonance circuit including a primary coil 13a and a primary capacitor 13b connected in parallel. The power receiver 23 has a resonance circuit including a secondary coil 23a and a secondary capacitor 23b connected in parallel. Both resonance frequencies are set to be the same.

  According to such a configuration, when high-frequency power is supplied to the power transmitter 13 (primary coil 13a) in a situation where the relative position between the power transmitter 13 and the power receiver 23 is in a position where magnetic field resonance is possible, The power receiver 23 (secondary coil 23a) performs magnetic field resonance. As a result, the power receiver 23 receives a part of the energy of the power transmitter 13. That is, the power receiver 23 receives high frequency power from the power transmitter 13.

  The load 22 is supplied with high-frequency power received by the power receiver 23. The load 22 includes a rectifier that rectifies high-frequency power received by the power receiver 23, a DC / DC converter that converts a voltage value of DC power rectified by the rectifier, and a voltage value that is converted by the DC / DC converter. And a vehicle battery to which direct-current power is supplied. The high frequency power received by the power receiver 23 is used for charging the vehicle battery.

  Incidentally, the DC / DC converter has a switching element that is periodically turned on / off, and performs voltage value conversion by turning on / off the switching element. In this case, the impedance ZL of the load 22, which is the impedance from the input terminal of the rectifier to the vehicle battery, is defined by the duty ratio of the switching element.

  Note that the impedance of the vehicular battery included in the load 22 varies depending on the power value of the supplied DC power. In this respect, in the present embodiment, the impedance from the DC / DC converter input terminal to the vehicle battery is constant by adjusting the on / off duty ratio of the switching element of the DC / DC converter in accordance with the fluctuation. It has become. For this reason, the impedance ZL of the load 22 is constant.

  The ground side device 11 includes a power source side controller 14 that controls the high frequency power source 12 and the like. The power supply side controller 14 determines whether or not high frequency power is supplied from the high frequency power supply 12 and controls the power value of the high frequency power supplied from the high frequency power supply 12.

  The vehicle-side device 21 includes a vehicle-side controller 24 configured to be able to communicate with the power supply-side controller 14 wirelessly. The non-contact power transmission apparatus 10 starts or ends power transmission through the exchange of information between the controllers 14 and 24.

  The non-contact power transmission device 10 includes a plurality of impedance converters 31 to 34. Specifically, the non-contact power transmission apparatus 10 includes a first impedance converter 31 and a second impedance converter 32 provided in the ground side device 11. The first impedance converter 31 and the second impedance converter 32 are provided between the high-frequency power source 12 and the power transmitter 13, and both are connected (arranged) in series. Further, the non-contact power transmission device 10 includes a third impedance converter 33 and a fourth impedance converter 34 provided in the vehicle-side device 21. The third impedance converter 33 and the fourth impedance converter 34 are provided between the power receiver 23 and the load 22, and both are connected in series.

  In the following description, the first impedance converter 31 and the second impedance converter 32 are converted into the primary side impedance converter group G1, and the third impedance converter 33 and the fourth impedance converter 34 are converted into the secondary side impedance. It is called instrument group G2. In the present embodiment, the primary side impedance converter group G1 and the secondary side impedance converter group G2 correspond to an “impedance converter”.

  Here, the inventors of the present invention contribute to the transmission efficiency between the power transmitter 13 and the power receiver 23 by the real part of the impedance Zq from the output terminal of the power receiver 23 (secondary coil 23a) to the load 22. I found out. Specifically, it has been found that a specific resistance value Rout that has a relatively higher transmission efficiency than other resistance values exists in the real part of the impedance Zq from the output terminal of the power receiver 23 to the load 22. In other words, the real part of the impedance Zq from the output terminal of the power receiver 23 to the load 22 has a specific resistance value Rout (second resistance value) in which transmission efficiency is higher than a predetermined resistance value (first resistance value). Found that there exists.

  Specifically, if a virtual load X is provided at the input end of the power transmitter 13, the resistance value of the virtual load X is Ra, and the virtual load X from the power receiver 23 (specifically, the output end of the power receiver 23). The specific resistance value Rout is √ (Ra × Rb) where Rb is the resistance value up to.

  The constants of the secondary side impedance converter group G2, specifically the third impedance converter 33, are variable, and the secondary side impedance converter group G2 is connected to the output end of the power receiver 23 based on the above knowledge. The impedance ZL of the load 22 is converted so that the impedance Zq to the load 22 approaches (preferably matches) the specific resistance value Rout. That is, the constants (impedances) of the third impedance converter 33 and the fourth impedance converter 34 are set to the impedance ZL of the load 22 so that the impedance Zq from the output terminal of the power receiver 23 to the load 22 becomes the specific resistance value Rout. It is set correspondingly. The specific resistance value Rout corresponds to the secondary side specific impedance. The constant (impedance) can be said to be a conversion ratio, an inductance, or a capacitance.

  The power value of the high-frequency power supplied from the high-frequency power source 12 depends on the impedance (impedance at the output end of the high-frequency power source 12) Zp from the output end of the high-frequency power source 12 to the load 22. In such a configuration, in the primary side impedance converter group G1, the impedance Zq from the output terminal of the power receiver 23 to the load 22 is set to the specific resistance value Rout so that high frequency power of a desired power value is supplied from the high frequency power source 12. Impedance conversion is performed on the impedance Zin from the input end of the power transmitter 13 to the load 22 in the approaching state.

  For example, the power value of the power supplied from the high-frequency power source 12 required for the power value of the DC power supplied to the vehicle battery of the load 22 to be a power value suitable for charging is set to a power value suitable for charging. . Then, the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 for supplying high frequency power having a power value suitable for charging from the high frequency power supply 12 is set as an input impedance Zt suitable for charging. In this case, the primary-side impedance converter group G1 is configured so that the impedance Zp from the output end of the high-frequency power source 12 to the load 22 approaches (preferably matches) the input impedance Zt suitable for the charging. Impedance conversion of the impedance Zin from the input end to the load 22 is performed. That is, the constants of the impedance converters 31 and 32 are the impedances from the input end of the power transmitter 13 to the load 22 so that the impedance Zp from the output end of the high frequency power supply 12 to the load 22 becomes the input impedance Zt suitable for charging. It is set corresponding to Zin. The input impedance Zt suitable for charging corresponds to the primary side specific impedance.

  In other words, the high frequency power supply 12 is configured to be able to supply high frequency power of a desired power value under the condition that the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 is the input impedance Zt suitable for the charging. It can be said that it is.

  Here, when the power transmitter 13 and the power receiver 23 deviate from a predetermined reference position, that is, when the relative positions of the power transmitter 13 and the power receiver 23 fluctuate, the impedance from the input end of the power transmitter 13 to the load 22 Zin varies. In this case, the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 deviates from the input impedance Zt suitable for charging as the target impedance. Then, the case where the high frequency electric power of a desired electric power value cannot be obtained may arise.

  The reference position is, for example, a position where the power transmitter 13 and the power receiver 23 are opposed to each other and are completely overlapped when viewed from the facing direction. At the reference position, for example, the primary side coil 13a and the secondary side coil 23a overlap each other when viewed from the facing direction.

On the other hand, the ground side apparatus 11 (non-contact power transmission device 10) of the present embodiment has a configuration for dealing with the above-described deviation. The configuration will be described.
As shown in FIG. 1, the ground side device 11 has a series connection in which a variable resistor 41 having a variable resistance value and a switching element 42 (switching unit) are connected in series separately from the primary side impedance converter group G1. A body 40 is provided. The series connection body 40 is provided between the high frequency power supply 12 and the first impedance converter 31. The series connection body 40 is connected in parallel to the high-frequency power source 12 and the first impedance converter 31. Specifically, the ground-side device 11 is provided with two wirings L1 and L2 that connect the high-frequency power source 12 and the first impedance converter 31 and are used to transmit high-frequency power, and are connected in series. 40 is connected to both of the two wirings L1 and L2.

  The switching element 42 is in a conduction state (ON state) in which the variable resistor 41 and the first impedance converter 31 are conducted, or in a cutoff state (OFF state) in which the variable resistor 41 and the first impedance converter 31 are cut off. It will be switched.

  According to this configuration, when the switching element 42 is in a conductive state, the high frequency power supplied from the high frequency power supply 12 is supplied to the power transmitter 13 via the variable resistor 41 and the primary side impedance converter group G1. The On the other hand, when the switching element 42 is in the cut-off state, the high-frequency power supplied from the high-frequency power source 12 is supplied to the power transmitter 13 via the primary side impedance converter group G1 without passing through the variable resistor 41. The

  The conduction state can also be said to be a connection state in which the variable resistor 41 and the first impedance converter 31 (primary side impedance converter group G1) are connected. Moreover, it can be said that the interruption | blocking state is a cancellation | release state in which the connection of the variable resistance 41 and the 1st impedance converter 31 was cancelled | released with a non-conduction state.

  Incidentally, the switching element 42 is in a cutoff state in the initial state. For this reason, normally, high frequency power is not supplied to the variable resistor 41. The initial value of the variable resistor 41 is set higher than the impedance from the input end of the first impedance converter 31 to the load 22 so that current does not easily flow through the variable resistor 41. Note that the variable range of the resistance value of the variable resistor 41 is set so that the voltage applied to the variable resistor 41 does not exceed the withstand voltage.

  The constants of the primary side impedance converter group G1, specifically, the constants of the first impedance converter 31 are variable. The constant variable range of the first impedance converter 31 is set so as to be able to cope with a positional deviation between the power transmitter 13 and the power receiver 23 that may occur in a normal usage mode, for example. Specifically, for example, it is assumed that there is a guide portion (for example, a wheel stopper or a white line) that guides the parking position of the vehicle on the installation surface on which the vehicle is installed. In this case, the variable range of the constant of the first impedance converter 31 is based on the variation in the parking position of the vehicle when the vehicle is parked based on the guide of the guide unit (the positional deviation between the power transmitter 13 and the power receiver 23). Is set to such an extent that a deviation between the impedance Zp from the output terminal to the load 22 and the input impedance Zt suitable for charging can be compensated.

  Here, the configuration for making the constant of the first impedance converter 31 variable is arbitrary. For example, when the first impedance converter 31 is configured by an LC circuit having an inductor and a capacitor, the inductance is reduced. A configuration is possible in which at least one of a variable variable inductor and a variable variable capacitor is provided. In addition, a plurality of LC circuits having different constants and a relay capable of selectively connecting a part of the plurality of LC circuits to both the high frequency power supply 12 and the second impedance converter 32 are provided. It may be a configuration.

  Note that the initial value of the primary side impedance converter group G1 is the load from the output end of the high frequency power supply 12 when the power transmitter 13 and the power receiver 23 are arranged at the reference position and the switching element 42 is in the cut-off state. The impedance Zp up to 22 is set to be the input impedance Zt suitable for charging.

  Further, the ground side device 11 measures the information on the impedance Zp from the output terminal of the high frequency power source 12 to the load 22, specifically, the voltage waveform and current waveform of the high frequency power supplied from the high frequency power source 12. A container 43 is provided. The primary side measuring instrument 43 transmits the measurement result to the power supply side controller 14.

  When the high frequency power is supplied from the high frequency power supply 12 in a situation where the power transmitter 13 and the power receiver 23 are arranged at positions where the magnetic field resonance is possible, the power supply side controller 14 displays the measurement result of the primary side measuring device 43 as the measurement result. Based on this, a primary side adjustment process for performing variable control of the constant of the first impedance converter 31 and switching control of the switching element 42 is executed.

  The primary side adjustment process will be described with reference to FIG. In the present embodiment, high-frequency power is constantly supplied from the high-frequency power source 12 during the execution of the primary side adjustment process. Further, the primary side adjustment process is performed by using a constant of the secondary side impedance converter group G2 (third impedance converter 33) so that the impedance Zq from the output terminal of the power receiver 23 to the load 22 approaches the specific resistance value Rout. It is executed after variable control is performed. During the execution of the primary side adjustment process, the variable control of the constants of the secondary side impedance converter group G2 is not executed, and the constants of the secondary side impedance converter group G2 are constant.

  First, in step S101, the measurement result of the primary side measuring instrument 43 is acquired, and the impedance Zp from the output end of the high frequency power supply 12 to the load 22 is grasped (measured) based on the acquired information.

  In subsequent step S102, it is determined whether or not the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 is approaching the input impedance Zt suitable for charging. Specifically, it is determined whether or not the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 is within a range (allowable range (Ztmin to Ztmax)) including the input impedance Zt suitable for charging.

  If the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 is within the allowable range, it is determined that there is no need to adjust the impedance, and the present process is terminated. On the other hand, when the impedance Zp is out of the allowable range, it means that the power value of the high-frequency power supplied from the high-frequency power source 12 is different from the desired power value. In this case, in step S103, it is determined whether there is an unset constant in the first impedance converter 31.

  Here, the unset constant is a constant that has not yet been set in the current primary side adjustment process among the constants that can be taken by the first impedance converter 31. Specifically, for example, when the first impedance converter 31 is configured by a plurality of LC circuits having different constants, the possible constants are constants of the respective LC circuits and constants obtained by combining them. For example, in the configuration in which the first impedance converter 31 includes a variable capacitor or a variable inductor, the constant that the first impedance converter 31 can take is from the minimum value of the variable range of the constant of the first impedance converter 31 to the maximum. This is a constant when the value is increased by a predetermined value.

  That is, the process of step S103 is a process of determining whether all constants that can be taken by the first impedance converter 31 have been set. In other words, in step S103, it is determined whether or not there is a constant for which the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 is not measured among a plurality of constants that can be taken by the first impedance converter 31. .

  If there is an unset constant, an affirmative decision is made in step S103 and the process proceeds to step S104. In step S104, variable control of the constant of the first impedance converter 31 is performed. Specifically, the constant of the first impedance converter 31 is set to one of the unset constants. Then, the process returns to step S101.

  That is, either (A) the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 is within the allowable range, or (B) setting all the constants that the first impedance converter 31 can take. The variable control (change) of the constant of the first impedance converter 31 and the grasp of the impedance Zp are performed until it is established. The constant of the first impedance converter 31 and the measurement result of the impedance Zp when set to the constant are associated with each other and stored in a predetermined storage area.

  Although the order of setting the unset constants is arbitrary, for example, it is preferable to sequentially adopt the smallest constants that can be taken. In this case, in step S103, it may be determined whether or not the currently set constant of the first impedance converter 31 is the maximum value. In addition, a configuration may be adopted in which constants to be preferentially set are narrowed down in consideration of a deviation amount between the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 and the input impedance Zt suitable for charging. Moreover, the structure which sets sequentially from the constant with a small difference with respect to an initial value may be sufficient.

  When there is no unset constant, it means that the variable control of the constant of the first impedance converter 31 does not allow the impedance Zp from the output end of the high frequency power supply 12 to the load 22 to fall within the allowable range. In other words, it means that further impedance adjustment is required. In this case, negative determination is made in step S103, and in step S105, among the constants of the first impedance converter 31, the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 is closest to the input impedance Zt suitable for charging. Set the hour constant. In steps S106 to S109, the impedance is adjusted using the variable resistor 41.

Specifically, first, in step S <b> 106, the switching element 42 is controlled so as to switch from the cut-off state to the conduction state, and the variable resistor 41 is connected to the first impedance converter 31.
In addition, as already demonstrated, the switching element 42 is a interruption | blocking state in an initial state. For this reason, during the variable control of the constant of the first impedance converter 31, that is, during the execution of the processing of Steps S101 to S104, the switching element 42 is in the cut-off state.

  Thereafter, in step S107, the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 is grasped. In step S108, it is determined whether or not the impedance Zp is within an allowable range.

  When the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 is within the allowable range, the present process is terminated as it is. On the other hand, if the impedance Zp is outside the allowable range, variable control of the resistance value of the variable resistor 41 is performed in step S109. Specifically, the resistance value of the variable resistor 41 is set to an unset resistance value, specifically, the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 is set to an unmeasured resistance value.

  As a variable control of the resistance value of the variable resistor 41, for example, a mode in which the resistance value is increased or decreased sequentially from the initial value can be considered. However, the present invention is not limited to this, and the mode of variable control is arbitrary. For example, the resistance value to be preferentially set may be narrowed down in consideration of the amount of deviation between the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 and the input impedance Zt suitable for charging.

  After step S109, the process returns to step S107. That is, variable control of the resistance value of the variable resistor 41 is performed until the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 falls within the allowable range.

  Even if the resistance value of the variable resistor 41 is set to any value, if the impedance Zp from the output end of the high-frequency power source 12 to the load 22 is out of the allowable range, an abnormality notification is given that there is an abnormality. To terminate the process and stop power transmission. Further, instead of abnormality notification, the resistance value of the variable resistor 41 is set when the impedance Zp from the output terminal of the high-frequency power supply 12 to the load 22 is closest to the input impedance Zt suitable for charging, and this processing is terminated. However, power transmission may be performed.

Next, the operation of this embodiment will be described.
When a deviation occurs between the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 and the input impedance Zt suitable for charging, the constant of the first impedance converter 31 can be changed so that the deviation is within an allowable range. Control is performed. When the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 is not within the allowable range only by the variable control of the constant of the first impedance converter 31, the variable resistor 41 and the first impedance converter 31 are used. And are connected. Then, variable control of the resistance value of the variable resistor 41 is performed so that the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 is within an allowable range.

According to the embodiment described in detail above, the following excellent effects are obtained.
(1) Primary side impedance converter group G1 having a plurality of impedance converters 31 and 32 between the input side of the power transmitter 13 (primary side coil 13a), specifically, between the high frequency power source 12 and the power transmitter 13. In addition, a variable resistor 41 is provided separately from the primary side impedance converter group G1. Then, the variable resistor 41 and the first impedance converter 31 of the primary side impedance converter group G1 are in a conductive state, or the variable resistor 41 and the first impedance converter 31 are cut off. A switching element 42 for switching is provided. As a result, when the switching element 42 is in a conductive state, the high frequency power is supplied to the power transmitter 13 via the variable resistor 41 and the primary side impedance converter group G1, so that the variable resistor 41 and the primary side are supplied. The impedance converter group G1 cooperates to perform impedance conversion. On the other hand, when the switching element 42 is in the cut-off state, the high frequency power is supplied to the power transmitter 13 only through the primary side impedance converter group G1, and the high frequency power is not supplied to the variable resistor 41. As a result, when the impedance adjustment using the variable resistor 41 is necessary, the switching element 42 is turned on. On the other hand, when the impedance adjustment using the variable resistor 41 is not necessary, the switching element 42 is shut off. By setting the state, it is possible to suppress unnecessary power loss while suitably adjusting the impedance.

  (2) A variable resistor 41 having a variable resistance value is used as a resistor used for adjusting the impedance. Thereby, compared with the case where resistance with a fixed resistance value is used, the adjustable range of impedance becomes wide. Therefore, the impedance can be adjusted more suitably.

  (3) The constant of the primary side impedance converter group G1 (specifically, the first impedance converter 31) is variable. Thereby, since both the resistance value of the variable resistor 41 and the constant of the 1st impedance converter 31 are variable, the adjustable range of an impedance is wider. Thereby, even if it is a case where the position shift of the power transmission device 13 and the power receiving device 23 is large, electric power transmission can be performed suitably.

  (4) The switching element 42 is in the cut-off state when the variable control of the constant of the first impedance converter 31 is performed, and when the impedance is further adjusted after the variable control of the constant of the first impedance converter 31 is performed. Furthermore, it was set as the structure which switches from a interruption | blocking state to a conduction | electrical_connection state. Thereby, before adjusting the impedance using the variable resistor 41, the power by supplying the high frequency power to the variable resistor 41 through adjusting the impedance by variable control of the constant of the first impedance converter 31. Loss can be avoided as much as possible. Further, when the impedance cannot be adjusted by adjusting the constant by the variable control of the constant of the first impedance converter 31, the impedance can be further adjusted by switching the switching element 42 from the cutoff state to the conductive state. Thereby, stable power transmission can be realized even when the adjustment of the impedance is difficult by the variable control of the constant of the first impedance converter 31.

  (5) Here, the amount of deviation between the impedance Zp from the output end of the high-frequency power supply 12 to the load 22 and the input impedance Zt suitable for charging, which may occur due to variations in normal use mode (parking mode), is determined to some extent. . For this reason, it is assumed that the variable range of the constant of the first impedance converter 31 is set corresponding to the deviation amount. On the other hand, although the frequency of occurrence is lower than that in a normal usage mode, it is desirable that power transmission can be performed stably even when non-contact power transmission is performed in a different usage mode. However, in order to cope with such a case where the occurrence frequency is low, it is possible to separately provide an impedance converter or the like having a variable constant, or to increase the variable range of the constant of the first impedance converter 31. It is not preferable from the viewpoint of simplification.

  In detail, for example, when a variable inductor or a variable capacitor having a wide variable range is provided, the variable inductor or the variable capacitor may be large, or an element having such a variable range may not be present in a general-purpose product. . However, if the variable range is expanded by a combination of a plurality of general-purpose products, there is a concern that the number of parts increases and the control becomes complicated as the number of controlled objects increases. In addition, in a configuration that realizes variable control of constants by selecting one of a plurality of LC circuits having different constants, it is necessary to increase the number of LC circuits to cope with a wide variable range, and the number of parts is also reduced. There is concern about an increase and an increase in size.

  On the other hand, in the present embodiment, apart from the primary side impedance converter group G1, it is easy to obtain a wide variable range as compared with a variable capacitor or the like, and a simple variable resistor 41, switching element 42, Was provided. As a result, it is possible to achieve both the avoidance of the inconvenience and the stable power transmission in the usage mode different from the normal use.

  (6) In the variable control of the constant of the first impedance converter 31, when the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 does not fall within the allowable range, the constant of the first impedance converter 31 can be taken. Among them, a constant is set when the impedance Zp is closest to the input impedance Zt suitable for charging as the target impedance. Thereafter, the impedance is adjusted using the variable resistor 41. As a result, it is possible to adjust the impedance by the variable resistor 41 in a state as close to the target impedance as possible.

(Second Embodiment)
The specific resistance value Rout as the target impedance is the configuration of the power transmitter 13 and the power receiver 23 (the shape and inductance of each coil 13a, 23a, the capacitance of each capacitor 13b, 23b, etc.), the relative of the power transmitter 13 and the power receiver 23. Determined by position. For this reason, when the power transmitter 13 and the power receiver 23 deviate from the reference position, that is, when the relative position of the power transmitter 13 and the power receiver 23 varies, the specific resistance value Rout varies.

  On the other hand, as shown in FIG. 3, in the present embodiment, the vehicle-side device 21 is connected in series with a variable resistor 51 and a switching element 52 connected in series separately from the secondary-side impedance converter group G2. A body 50 is provided. The series connection body 50 is provided between the power receiver 23 and the third impedance converter 33, and is connected in parallel to the power receiver 23 and the third impedance converter 33. Specifically, the vehicle-side device 21 is provided with two wirings L3 and L4 that connect the power receiver 23 and the third impedance converter 33 and are used for transmission of high-frequency power, and are connected in series. 50 is connected to both of the two wirings L3 and L4.

  The switching element 52 includes a conductive state (ON state) in which the variable resistor 51 and the third impedance converter 33 (secondary impedance converter group G2) are conducted, or the variable resistor 51 and the third impedance converter 33 are connected. Switch to the blocked state (off state).

  According to such a configuration, when the switching element 52 is in a conductive state, the high frequency power received by the power receiver 23 is supplied to the load 22 via the variable resistor 51 and the secondary impedance converter group G2 ( Transmission). On the other hand, when the switching element 52 is in the cut-off state, the high frequency power received by the power receiver 23 is supplied to the load 22 via the secondary impedance converter group G2 without passing through the variable resistor 51. The

  Incidentally, the switching element 52 is in a cutoff state in the initial state. For this reason, normally, the high frequency power is not supplied to the variable resistor 51. The initial value of the variable resistor 51 is set higher than the impedance from the input end of the third impedance converter 33 to the load 22 so that current does not easily flow through the variable resistor 51.

  As already explained, the constants of the secondary impedance converter group G2, specifically the third impedance converter 33, are variable. The constant variable range of the third impedance converter 33 is set so as to be able to cope with a positional shift between the power transmitter 13 and the power receiver 23 that may occur in a normal usage mode, for example. Specifically, for example, the constant variable range of the third impedance converter 33 is a variation in the parking position of the vehicle when the vehicle is parked based on the guide of the guide portion on the installation surface (positional deviation of the power transmitter 13 and the power receiver 23). Is set to such an extent that the deviation between the impedance Zq from the output terminal of the power receiver 23 to the load 22 and the specific resistance value Rout can be compensated.

  Note that the initial value of the third impedance converter 33 is from the output end of the power receiver 23 to the load 22 when the power transmitter 13 and the power receiver 23 are arranged at the reference position and the switching element 52 is in the cutoff state. Is set to have a specific resistance value Rout. Moreover, since the specific structure which makes the constant of the 3rd impedance converter 33 variable is the same as that of the 1st impedance converter 31 of 1st Embodiment, description is abbreviate | omitted.

  The vehicle-side device 21 includes a secondary-side measuring device 53 that measures the voltage waveform and current waveform of the high-frequency power received by the power receiver 23. The secondary side measuring device 53 transmits the measurement result to the vehicle side controller 24.

  The vehicle-side controller 24 is based on the measurement results of the measuring instruments 43 and 53 when high-frequency power is supplied from the high-frequency power supply 12 in a situation where the power transmitter 13 and the power receiver 23 are arranged at positions where magnetic field resonance is possible. Then, the secondary side adjustment process for performing variable control of the constant of the third impedance converter 33, switching control of the switching element 52, and the like is executed.

The secondary side adjustment process will be described with reference to FIG. In the present embodiment, high-frequency power is constantly supplied from the high-frequency power source 12 during execution of the secondary side adjustment process.
First, in step S201, the transmission efficiency is calculated (measured) based on the measurement results of the measuring instruments 43 and 53. Specifically, the vehicle-side controller 24 requests the power value of the high-frequency power supplied to the primary-side measuring instrument 43 from the power supply-side controller 14. The power supply side controller 14 acquires the measurement result of the primary side measuring device 43 based on the request | requirement, and calculates the electric power value of the high frequency electric power supplied to the primary side measuring device 43 from the measurement result. Then, the power supply side controller 14 transmits the calculated power value to the vehicle side controller 24. The vehicle-side controller 24 calculates the power value of the high-frequency power received by the power receiver 23 from the measurement result of the secondary-side measuring device 53, and based on the power value and the power value acquired from the power-supply side controller 14. To calculate the transmission efficiency.

  In step S202, it is determined whether or not the transmission efficiency calculated in step S201 is equal to or higher than a predetermined threshold efficiency. The threshold efficiency is set, for example, to a transmission efficiency in a situation where the impedance Zq from the output terminal of the power receiver 23 to the load 22 is the specific resistance value Rout or a value lower than that by a predetermined margin. The threshold efficiency is not limited to this, and is arbitrary as long as it is a transmission efficiency that does not hinder power transmission.

  If the transmission efficiency is equal to or higher than the threshold efficiency, it is determined that there is no need to adjust the impedance, and this process is terminated. On the other hand, when the transmission efficiency is less than the threshold efficiency, it means that there is a difference between the impedance Zq from the output terminal of the power receiver 23 to the load 22 and the specific resistance value Rout. In this case, the process proceeds to step S203, and it is determined whether or not there is an unset constant in the third impedance converter 33. Note that the specific processing content of step S203 is the same as that of step S103 of the first embodiment, and a description thereof will be omitted.

  If an unset constant exists in the third impedance converter 33, the process proceeds to step S204, and the variable control of the constant of the third impedance converter 33 is performed. Specifically, the constant of the third impedance converter 33 is set to one of unset constants. Then, the process returns to step S201.

  If there is no unset constant in the third impedance converter 33, it means that the transmission efficiency does not exceed the threshold efficiency even though all the constants that the third impedance converter 33 can take are set. That is, the constant variable control of the third impedance converter 33 means that the deviation of the impedance Zq from the output terminal of the power receiver 23 to the load 22 with respect to the specific resistance value Rout cannot be within an allowable range. In this case, a negative determination is made in step S203, and the process proceeds to step S205. In step S205, among the plurality of set constants, a constant at the time of maximum efficiency, specifically, a constant at the time when the transmission efficiency is maximized is set.

  In subsequent step S <b> 206, the switching element 52 is controlled to switch from the cutoff state to the conductive state, and the variable resistor 51 is connected to the third impedance converter 33. As already described, the switching element 52 is in the cutoff state in the initial state. Therefore, similarly to the switching element 42 of the first embodiment, the switching element 52 is in the cut-off state during the variable control of the constant of the third impedance converter 33, that is, during the execution of the processing of Step S201 to Step S204. Yes.

  Thereafter, the transmission efficiency is calculated in step S207, and it is determined whether or not the transmission efficiency is equal to or higher than the threshold efficiency in step S208. If the transmission efficiency is equal to or higher than the threshold efficiency, the process is terminated as it is. If the transmission efficiency is less than the threshold efficiency, variable control of the resistance value of the variable resistor is performed in step S209, and the process proceeds to step S207. Return. That is, variable control of the resistance value of the variable resistor 51 is performed until the transmission efficiency becomes equal to or higher than the threshold efficiency.

  Incidentally, the process of performing variable control of the constant of the third impedance converter 33 or the resistance value of the variable resistor 51 so that the transmission efficiency is equal to or higher than the threshold efficiency is performed by the impedance Zq from the output terminal of the power receiver 23 to the load 22. It can be said that this is a process for reducing the deviation from the specific resistance value Rout.

  In addition, even when the resistance value of the variable resistor 51 is set to any value, if the transmission efficiency is less than the threshold efficiency, an abnormality notification is given as an abnormality, the present process is terminated, and power transmission is performed. May be canceled. Further, instead of abnormality notification, the resistance value of the variable resistor 51 when the transmission efficiency is closest to the threshold efficiency may be set, and this process may be terminated to perform power transmission.

Next, the operation of this embodiment will be described.
When a deviation occurs between the impedance Zq from the output terminal of the power receiver 23 to the load 22 and the specific resistance value Rout and the transmission efficiency becomes less than the threshold efficiency, the third is set so that the transmission efficiency becomes equal to or higher than the threshold efficiency. Variable control of the constant of the impedance converter 33 is performed. In this case, the variable resistor 51 and the third impedance converter 33 are connected if the transmission efficiency does not exceed the threshold efficiency only by the constant variable control of the third impedance converter 33. Then, variable control of the resistance value of the variable resistor 51 is performed so that the transmission efficiency becomes equal to or higher than the threshold efficiency.

According to this embodiment explained in full detail above, in addition to the effect similar to (2) and (5) mentioned above, there exist the following outstanding effects.
(7) A secondary impedance converter group G2 having a plurality of impedance converters 33 and 34 between the power receiver 23 (secondary coil 23a) and the load 22, and a secondary impedance converter group G2. Separately, a variable resistor 51 is provided. And it switches to the conduction | electrical_connection state in which the variable resistance 51 and the 3rd impedance converter 33 of the secondary side impedance converter group G2 were conducted, or the interruption | blocking state in which the variable resistance 51 and the 3rd impedance converter 33 were interrupted | blocked. A switching element 52 is provided. Thereby, when the switching element 52 is in a conductive state, the high-frequency power received by the power receiver 23 is supplied to the load 22 via the variable resistor 51 and the secondary side impedance converter group G2. The variable resistor 51 and the secondary impedance converter group G2 cooperate to perform impedance conversion. On the other hand, when the switching element 52 is in the cut-off state, the high frequency power is supplied to the load 22 only through the secondary side impedance converter group G2, and the high frequency power is not supplied to the variable resistor 51. Thereby, unnecessary power loss can be suppressed while impedance adjustment is suitably performed.

  (8) The constant of the secondary side impedance converter group G2 (specifically, the third impedance converter 33) is variable. Thereby, since both the resistance value of the variable resistor 51 and the constant of the third impedance converter 33 are variable, the adjustable range of impedance is wider. Thereby, even if it is a case where the position shift of the power transmission device 13 and the power receiving device 23 is large, electric power transmission can be performed suitably.

  (9) When the variable control of the constant of the third impedance converter 33 is performed, the switching element 52 is in the cut-off state, and when the impedance is further adjusted after the variable control of the constant of the third impedance converter 33 is performed. Furthermore, it was set as the structure which switches from a interruption | blocking state to a conduction | electrical_connection state. As a result, it is possible to avoid as much power loss as possible when high frequency power is supplied to the variable resistor 51. Further, when the impedance cannot be adjusted by adjusting the constant by the variable control of the constant of the first impedance converter 31, the impedance can be further adjusted by switching the switching element 52 from the cut-off state to the conductive state. Thereby, stable power transmission can be realized even when the adjustment of the impedance is difficult by the variable control of the constant of the first impedance converter 31.

  (10) If the transmission efficiency does not exceed the threshold efficiency in the variable control of the constant of the third impedance converter 33, the constant at the time when the transmission efficiency is maximum among the constants that the third impedance converter 33 can take is set. The impedance is adjusted using the variable resistor 51. Thereby, the impedance can be adjusted by the variable resistor 51 while the transmission efficiency is as close to the threshold efficiency as possible.

In addition, you may change each said embodiment as follows.
In each embodiment, the variable resistors 41 and 51 having variable resistance values are employed as the impedances to be adjusted. However, the present invention is not limited to this, and resistors having a fixed resistance value may be employed. Even in this case, impedance conversion by resistance is performed by switching the switching elements 42 and 52 from the cutoff state to the conductive state. However, in view of the fact that the impedance can be adjusted more preferably, the resistance value is preferably variable.

  In the first embodiment, the variable resistor 41 is connected in parallel to the high-frequency power source 12 and the first impedance converter 31, but is not limited thereto. For example, as shown in FIG. 5, the variable resistor 41 may be connected in series with the high frequency power supply 12 and the first impedance converter 31. In this case, one wiring L1 of the two wirings L1 and L2 has a bifurcated structure including the first wiring L11 and the second wiring L12, and the wiring configuring the power transmission path is the first wiring L11 or A relay 61 that switches to the second wiring L12 may be provided. And it is good to provide the variable resistance 41 only in the 2nd wiring L12. Further, the power supply side controller 14 normally controls the relay 61 so that high frequency power is transmitted through the first wiring L11, and in addition to the variable control of the constant of the first impedance converter 31, further adjustment of the impedance is necessary. In such a case, the relay 61 may be controlled so that high-frequency power is transmitted via the second wiring L12. The state in which high-frequency power is transmitted through the first wiring L11 corresponds to the “cut-off state”, and the state in which high-frequency power is transmitted through the second wiring L12 corresponds to the “conduction state”.

  Incidentally, from the viewpoint of reducing the power loss, it is preferable that the resistance value of the variable resistor 41 is small. That is, when the resistors are connected in series, it is preferable to select a resistor having a small resistance value and a low withstand voltage as compared with the case where the resistors are connected in parallel.

Similarly in the second embodiment, the variable resistor 51 may be connected in series to the power receiver 23 and the third impedance converter 33.
(Circle) each embodiment and the said another example may be combined. That is, the ground-side device 11 includes a resistor that can be connected in series to the high-frequency power source 12 and the first impedance converter 31 and a resistor that can be connected in parallel to the high-frequency power source 12 and the first impedance converter 31. Good. Similarly, the vehicle-side device 21 includes a resistor that can be connected in series to the power receiver 23 and the third impedance converter 33 and a resistor that can be connected in parallel to the power receiver 23 and the third impedance converter 33. Also good.

  In the first embodiment, only one series connection body 40 is provided, but the present invention is not limited to this. For example, as shown in FIG. 6, a plurality of serially connected bodies 70 and 80 may be connected in parallel to each other. Of the plurality of series connection bodies 70, 80, the first series connection body 70 has a first resistance 71 and a first switching element 72 having a fixed resistance value, and the second series connection body 80 has a resistance value fixed. The second resistor 81 and the second switching element 82 are included. According to such a configuration, by performing switching control of the switching elements 72 and 82, the combined resistance value by the series connection bodies 70 and 80 becomes variable. Thereby, a plurality of types of resistance values can be realized. Therefore, impedance adjustment can be suitably performed without using the variable resistors 41 and 51 having variable resistance values.

Similarly, in the second embodiment, a plurality of serially connected bodies connected in parallel to each other may be provided.
In the other example, the resistance value of the first resistor 71 and the resistance value of the second resistor 81 may be the same or different. Further, instead of the resistors 71 and 81 having fixed resistance values, variable resistors having variable resistance values may be used.

  In the above example, the number of series-connected bodies is not limited to two, and may be three or more. Furthermore, a plurality of serially connected bodies connected in parallel to each other may be provided in series with the high-frequency power source 12 and the first impedance converter 31 or the power receiver 23 and the third impedance converter 33. In this case, a bypass line having no resistance may be provided separately, and the power transmission path may be switched as necessary.

  In each embodiment, after the variable control of the constants of the impedance converters 31 and 33 is performed, the variable resistors 41 and 51 and the impedance converters 31 and 33 are connected, and the resistance values of the variable resistors 41 and 51 are changed. Although the configuration in which the variable control is sometimes performed is not limited thereto, the order in which the variable control is performed may be reversed. However, from the viewpoint of power loss, it is preferable to deal with variable control of the constants of the impedance converters 31 and 33 as much as possible.

  O It is good also as a structure which provides both the serial connection body 40 of 1st Embodiment, and the serial connection body 50 of 2nd Embodiment. In this case, the primary side adjustment process may be executed after the secondary side adjustment process. Accordingly, it is possible to avoid duplication of processing in which the impedance Zin from the input end of the power transmitter 13 to the load 22 is changed by the secondary side adjustment processing and the primary side adjustment processing needs to be executed again.

A specific configuration of each of the impedance converters 31 to 34 is arbitrary. For example, it may be composed of an LC circuit or a transformer.
Further, the specific configuration of the LC circuit is arbitrary, and may be, for example, any of L-type, inverted L-type, π-type, and T-type, or other than this. When a class D amplifier is used as a part of the high frequency power supply 12, the first impedance converter 31 may be other than the L type.

  In each embodiment, the primary impedance converter group G1 has a multi-stage configuration including a plurality of impedance converters 31 and 32, but is not limited thereto. For example, the second impedance converter 32 may be omitted. Similarly, the fourth impedance converter 34 may be omitted for the secondary impedance converter group G2. In short, the “impedance converter” may be configured by one impedance converter or a plurality of impedance converters. However, if attention is paid to the fact that the constant in one impedance converter can be reduced by making the impedance converter multistage, the multistage configuration is preferable.

  The execution timing of the primary side adjustment process and the secondary side adjustment process (hereinafter simply referred to as adjustment process) is arbitrary. For example, it may be executed before charging the vehicle battery, or may be executed periodically during charging of the vehicle battery.

  In the adjustment process, when grasping the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 or calculating the transmission efficiency, power is supplied from the high frequency power supply 12 while the constants of the impedance converters 31 and 33 are variably controlled. Or, during the variable control of the resistance values of the variable resistors 41 and 51, the power supply by the high frequency power source 12 may be stopped.

  ○ For example, before charging power is supplied from the high-frequency power supply 12 and the vehicle battery is fully charged, the adjustment power having a power value smaller than that of the charging power is supplied from the high-frequency power supply 12. Thus, the adjustment process may be executed in a situation where the adjustment power is being supplied. In this case, if the impedance ZL of the load 22 is made constant by adjusting the ON / OFF duty ratio of the switching element of the DC / DC converter in accordance with the fluctuation of the impedance ZL of the load 22 due to the different power values. Good. Further, instead of adjusting the duty ratio, a fixed resistor having a constant resistance value regardless of the power value of the supplied high-frequency power, and the supply destination of the high-frequency power to the load 22 or the fixed resistor separately from the load 22 It is good also as a structure which provides the relay to switch and performs an adjustment process in the condition where high frequency electric power is supplied to fixed resistance.

  ○ Here, paying attention to the fact that the duty ratio is adjusted so that the impedance ZL from the input terminal of the rectifier to the vehicle battery is constant, the DC / DC converter is connected from the input terminal of the rectifier to the vehicle battery. It can be said that the impedance conversion unit performs impedance conversion so that the impedance ZL becomes a predetermined value. And adjustment of the duty ratio corresponding to the fluctuation | variation of the impedance of the vehicle battery which fluctuates according to the electric power value (electric power value of the high frequency electric power received by the power receiver 23) of the high frequency electric power supplied from the high frequency power supply 12 is performed. Corresponds to variable control of impedance. In this case, for example, when a series connection body is provided between the rectifier and the DC / DC converter, and the adjustment of the duty ratio cannot be adjusted to the predetermined value, the impedance adjustment using the resistance of the series connection body is performed. May be performed.

  In the above configuration, the vehicle battery corresponds to the load. That is, the load is supplied with high-frequency power received by the power receiver 23 or DC power rectified from the high-frequency power.

  In each embodiment, the impedance ZL of the load 22 is constant by adjusting the on / off duty ratio of the switching element of the DC / DC converter. However, the present invention is not limited to this, and the duty ratio may not be adjusted. The DC / DC converter may be omitted. In this case, when the power value of the high-frequency power supplied from the high-frequency power source 12 is changed, the impedance ZL of the load 22 varies, and the impedance Zq from the output terminal of the power receiver 23 to the load 22 deviates from the specific resistance value Rout. . Further, the impedance Zp from the output terminal of the high-frequency power source 12 to the load 22 deviates from the input impedance Zt suitable for charging. In order to cope with these deviations, the controllers 14 and 24 may perform adjustment processing when the power value of the high-frequency power supplied from the high-frequency power source 12 is changed.

  In 1st Embodiment, although the serial connection body 40 was installed between the high frequency power supply 12 and the 1st impedance converter 31, it is not restricted to this, The installation position is the power transmission device 13 (primary side coil 13a). ) On the input side. For example, the serial connection body 40 may be disposed between the first impedance converter 31 and the second impedance converter 32 or between the second impedance converter 32 and the power transmitter 13.

  Similarly, in the second embodiment, the installation position of the series connection body 50 is arbitrary as long as it is between the power receiver 23 (secondary coil 23 a) and the load 22. For example, the series connection body 50 may be disposed between the third impedance converter 33 and the fourth impedance converter 34 or between the fourth impedance converter 34 and the load 22. In short, the series connection body may be provided between the high-frequency power source 12 and the load (the load 22 or the vehicle battery), that is, on any power transmission path of the high-frequency power.

  The threshold efficiency (referred to as the first threshold efficiency) used in the determination process in step S202 may be different from the threshold efficiency (referred to as the second threshold efficiency) used in the determination process in step S208. For example, the first threshold efficiency may be higher than the second threshold efficiency. As a result, power transmission with a relatively high transmission efficiency is realized in a normal use mode, while a decrease in transmission efficiency is allowed to some extent in a different use mode (when the positional deviation is relatively large). However, power transmission can be performed.

  Similarly, the allowable range (referred to as the first allowable range) used in the determination process in step S102 may be different from the allowable range (referred to as the second allowable range) used in the determination process in step S108.

  ○ The subject of the adjustment process is arbitrary. For example, the vehicle side controller 24 may execute the primary side adjustment process. In this case, the power supply side controller 14 transmits information necessary for processing (for example, measurement results of the primary side measuring device 43) to the vehicle side controller 24. The vehicle-side controller 24 transmits various commands and the like to the power-supply-side controller 14, and the power-supply-side controller 14 performs variable control of the resistance value of the variable resistor 41 or the constant of the first impedance converter 31 based on the command. Switching control of the switching element 42 may be performed. Similarly, the power supply side controller 14 may execute the secondary side adjustment process, or a controller other than the controllers 14 and 24 may execute the adjustment process.

  In the second embodiment, the maximum value of transmission efficiency (referred to as the first maximum value) obtained by variable control of the constant of the third impedance converter 33 and the transmission obtained by variable control of the resistance value of the variable resistor 51 When the first maximum value is higher than the second maximum value by comparing with the maximum value of efficiency (referred to as the second maximum value), the switching element 52 may be switched from the conduction state to the cutoff state.

The constants of the second impedance converter 32 and the fourth impedance converter 34 may be fixed or variable.
The constant of the primary side impedance converter group G1 (first impedance converter 31) may be fixed, and the constant of the secondary side impedance converter group G2 (third impedance converter 33) is fixed. May be.

  In the first embodiment, the primary side adjustment process is executed after the variable control of the constants of the secondary side impedance converter group G2, but the present invention is not limited to this, and the secondary side impedance is executed after the execution of the primary side adjustment process. You may perform variable control of the constant of the converter group G2.

  The secondary impedance converter group G2 performs impedance conversion so that the impedance Zq from the output terminal of the power receiver 23 to the load 22 approaches the specific resistance value Rout, but is not limited thereto. For example, in a configuration in which a power source is used as the high frequency power source 12, the secondary side impedance converter group G 2 includes the impedance Zq from the output end of the power receiver 23 to the load 22 and the output end of the power receiver 23 to the high frequency power source 12. Impedance conversion may be performed so as to match the impedance.

  In each embodiment, the primary side impedance converter group G1 is configured to perform impedance conversion so that the impedance Zp from the output terminal of the high frequency power supply 12 to the load 22 approaches the input impedance Zt suitable for charging. For example, the impedance conversion may be performed so that the power factor is improved (reactance approaches 0).

  In addition, when a power source is used as the high frequency power source 12, the primary side impedance converter group G 1 is configured so that the impedance Zp from the output end of the high frequency power source 12 to the load 22 matches the output impedance of the high frequency power source 12. Impedance conversion may be performed. In this case, the primary measuring instrument 43 measures the reflected wave power from the power transmitter 13 toward the high frequency power supply 12.

The high frequency power supply 12 may be any of a voltage source, a current source, and a power source.
The waveform of the high frequency power supplied from the high frequency power source 12 is arbitrary, and may be, for example, a sine wave or a rectangular wave.

○ The high frequency power supply 12 may be omitted. In this case, the system power supply and the first impedance converter 31 are connected.
In each embodiment, the resonance frequency of the power transmitter 13 and the resonance frequency of the power receiver 23 are set to be the same. However, the present invention is not limited to this, and may be different within a range in which power transmission is possible.

In each embodiment, the power transmitter 13 and the power receiver 23 have the same configuration, but are not limited to this, and may have different configurations.
In each embodiment, the primary coil 13a and the primary capacitor 13b are connected in parallel. However, the present invention is not limited to this, and may be connected in series. Similarly, the secondary coil 23a and the secondary capacitor 23b may be connected in series.

In each embodiment, the capacitors 13b and 23b are provided, but these may be omitted. In this case, magnetic field resonance is performed using the parasitic capacitances of the coils 13a and 23a.
In each embodiment, magnetic field resonance is used to realize non-contact power transmission. However, the present invention is not limited to this, and electromagnetic induction may be used.

  In each embodiment, the non-contact power transmission device 10 is applied to a vehicle, but is not limited thereto, and may be applied to other devices. For example, it may be applied to charge a battery of a mobile phone.

  The power transmitter 13 may have a configuration including a resonance circuit including a primary side coil 13a and a primary side capacitor 13b, and a primary side coupling coil that is coupled to the resonance circuit by electromagnetic induction. Similarly, the power receiver 23 may include a resonance circuit including a secondary coil 23a and a secondary capacitor 23b, and a secondary coupling coil coupled to the resonance circuit by electromagnetic induction.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(A) an AC power supply capable of supplying the AC power to the primary coil;
The impedance converter is provided between the AC power source and the primary coil, and performs impedance conversion so that the impedance of the output end of the AC power source approaches a predetermined primary side specific impedance. The power transmission apparatus as described in any one of Claims 1-4.

(B) The power transmission device according to any one of claims 1 to 4 and (A), wherein the impedance converter includes a plurality of impedance converters connected in series.
6. The impedance conversion unit according to claim 5, wherein the impedance conversion unit performs impedance conversion so that an impedance from an output end of the secondary side coil to the load approaches a predetermined secondary side specific impedance. Power receiving equipment.

  When attention is paid to this technical idea, “the case where the impedance is further adjusted after the variable control of the impedance of the impedance converter” means that the secondary side is specified even if the impedance of the impedance converter is changed, for example. This is a case where the deviation of the impedance from the output end of the secondary coil to the load with respect to the impedance is outside the allowable range.

  DESCRIPTION OF SYMBOLS 10 ... Non-contact electric power transmission apparatus, 11 ... Ground side apparatus (power transmission apparatus), 12 ... High frequency power supply, 13a ... Primary side coil, 14 ... Power supply side controller, 21 ... Vehicle side apparatus (power receiving apparatus), 22 ... Load, 23a ... secondary coil, 24 ... vehicle side controller, 31-34 ... impedance converter, 40, 50 ... series connection, 41, 51 ... variable resistance, 42, 52 ... switching element, 43, 53 ... measuring instrument.

Claims (6)

In a power transmission device having a primary coil to which AC power is supplied and capable of transmitting the AC power in a non-contact manner to a power receiving device having a secondary coil,
An impedance converter provided on the input side of the primary coil and performing impedance conversion;
A resistor provided separately from the impedance converter,
The resistance is connected to the impedance converter, and the AC power is supplied to the primary coil via the resistor and the impedance converter, or the resistor and the impedance converter are interrupted. A switching element that switches to a cut-off state in which the AC power is supplied to the primary coil through the impedance converter,
A power transmission device comprising:   The power transmission device according to claim 1, wherein the resistor is a variable resistor having a variable resistance value. A plurality of series connection bodies in which the resistor and the switching element are connected in series,
The power transmission device according to claim 1, wherein the plurality of serially connected bodies are connected to each other in parallel. The impedance of the impedance converter is variable,
The switching element is in the cut-off state when the variable control of the impedance of the impedance converter is performed, and the cut-off when the impedance is further adjusted after the variable control of the impedance of the impedance converter. The power transmission apparatus as described in any one of Claims 1-3 which switches from a state to the said conduction | electrical_connection state. In a power receiving device capable of receiving the AC power in a contactless manner from a power transmitting device having a primary side coil to which AC power is supplied,
A secondary coil capable of receiving the AC power in a non-contact manner from the primary coil;
Load,
An impedance converter that is provided between the secondary coil and the load and performs impedance conversion;
A resistor provided separately from the impedance converter,
The resistance is connected to the impedance converter, and the power is transmitted from the secondary coil to the load via the resistor and the impedance converter, or the resistor and the impedance converter are connected. And a switching element that switches to a cut-off state in which power transmission is performed from the secondary coil toward the load via the impedance converter,
A power receiving device comprising: AC power supply capable of supplying AC power,
A primary coil to which the AC power is supplied;
A secondary coil capable of receiving the AC power in a non-contact manner from the primary coil;
Load,
In a non-contact power transmission device comprising:
An impedance converter that is provided between the AC power source and the load and performs impedance conversion;
A resistor provided separately from the impedance converter,
The resistance is connected to the impedance converter, and the power is transmitted through the resistor and the impedance converter, or the resistor and the impedance converter are disconnected, and the impedance converter is connected to the impedance converter. A switching element that switches to a cut-off state where power transmission is performed,
A non-contact power transmission device comprising: