JP6685015B2 - NON-CONTACT POWER FEEDER, NON-CONTACT POWER TRANSMISSION SYSTEM, PROGRAM, AND METHOD FOR CONTROLLING NON-CONTACT POWER FEED DEVICE - Google Patents

Description

  The present invention relates to a non-contact power supply device, a non-contact power transmission system, a program, and a method for controlling the non-contact power supply device, and more specifically, a non-contact power supply device that non-contactly supplies power to a load, a non-contact power transmission system, The present invention relates to a program and a method for controlling a contactless power supply device.

  Conventionally, a contactless power supply device has been proposed that supplies power to a load in a contactless manner by using electromagnetic induction (see, for example, Patent Document 1).

  The non-contact power supply device described in Patent Document 1 includes a primary coil (power supply coil) that supplies electric power by generating a magnetic field, and is used for supplying power to a moving body such as an electric vehicle. An electric vehicle is equipped with a contactless power receiving device. The non-contact power receiving device includes a secondary coil (power receiving coil) and a storage battery, and stores the electric power supplied from the primary coil of the non-contact power feeding device to the secondary coil in the storage battery.

JP, 2013-243929, A

  By the way, in the non-contact power feeding device as described above, depending on the relative positional relationship between the primary coil (power feeding coil) of the non-contact power feeding device and the secondary coil (power receiving coil) of the load (moving body). , The coupling coefficient between the primary coil and the secondary coil changes. Therefore, when the relative positional relationship between the primary side coil and the secondary side coil changes, the output power output from the contactless power supply device may decrease, and the output power may be insufficient with respect to the required power. is there.

  The present invention has been made in view of the above circumstances, and even if the relative positional relationship between the power feeding side coil and the power receiving side coil changes, a non-contact power feeding device and a non-contact power source that can easily secure necessary power in a short time. An object of the present invention is to provide a transmission system, a program, and a method for controlling a contactless power supply device.

  A contactless power supply device according to one embodiment of the present invention includes an inverter circuit, a power supply side coil, a power correction circuit, and a control circuit. The inverter circuit has a plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points. The inverter circuit converts the DC voltage applied to the pair of input points into an AC voltage by switching the plurality of conversion switch elements, and outputs the AC voltage from the pair of output points. The power feeding side coil is electrically connected between the pair of output points, and supplies the output power to the power receiving side coil in a contactless manner by applying the AC voltage. The power correction circuit is electrically connected between at least one of the pair of output points and the power feeding side coil, and has an adjustment capacitor and a plurality of adjustment switch elements. The power correction circuit charges and discharges the adjustment capacitor by switching the plurality of adjustment switch elements. The control circuit controls the plurality of conversion switch elements with a first drive signal, and controls the plurality of adjustment switch elements with a second drive signal. The inverter circuit operates in a lag mode in which the current phase is delayed with respect to the voltage phase. The control circuit is configured to adjust the magnitude of the output power by adjusting a first phase difference that is a phase delay of the second drive signal with respect to the first drive signal. The control circuit uses the second phase difference to determine a first phase difference in which the time for which the adjustment capacitor is charged and the time for which the adjustment capacitor is discharged are equal in one cycle of the second drive signal. Obtained as the power control start angle. The control circuit adjusts the magnitude of the output power by adjusting the first phase difference within a range equal to or smaller than the power control start angle. The second phase difference is a delay in the phase of the current flowing through the power feeding side coil with respect to the output voltage of the inverter circuit.

  A non-contact power transmission system according to one aspect of the present invention includes the non-contact power feeding device and a non-contact power receiving device having the power receiving side coil. The non-contact power receiving device is configured such that the output power is supplied from the non-contact power feeding device to the power receiving side coil in a non-contact manner.

  A program according to one embodiment of the present invention causes a computer used for a contactless power supply device to function as a control unit and an acquisition unit. The contactless power supply device includes an inverter circuit, a power supply side coil, and a power correction circuit. The inverter circuit has a plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points. The inverter circuit converts the DC voltage applied to the pair of input points into an AC voltage by switching the plurality of conversion switch elements, and outputs the AC voltage from the pair of output points. The power feeding side coil is electrically connected between the pair of output points, and supplies the output power to the power receiving side coil in a contactless manner by applying the AC voltage. The power correction circuit is electrically connected between at least one of the pair of output points and the power feeding side coil, and has an adjustment capacitor and a plurality of adjustment switch elements. The power correction circuit charges and discharges the adjustment capacitor by switching the plurality of adjustment switch elements. The inverter circuit operates in a delay mode in which the current phase is delayed with respect to the voltage phase. The control unit controls the plurality of conversion switch elements with a first drive signal and controls the plurality of adjustment switch elements with a second drive signal. The controller adjusts the magnitude of the output power by adjusting a first phase difference which is a phase delay of the second drive signal with respect to the first drive signal. The acquisition unit uses the second phase difference to determine a first phase difference in which the time for which the adjustment capacitor is charged and the time for which the adjustment capacitor is discharged are equal in one cycle of the second drive signal. Obtained as the power control start angle. The controller adjusts the magnitude of the output power by adjusting the first phase difference within a range equal to or less than the power control start angle. The second phase difference is a delay in the phase of the current flowing through the power feeding side coil with respect to the output voltage of the inverter circuit.

  A control method for a contactless power supply device according to one aspect of the present invention includes a control process and an acquisition process. The contactless power supply device includes an inverter circuit, a power supply side coil, and a power correction circuit. The inverter circuit has a plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points. The inverter circuit converts the DC voltage applied to the pair of input points into an AC voltage by switching the plurality of conversion switch elements, and outputs the AC voltage from the pair of output points. The power feeding side coil is electrically connected between the pair of output points, and supplies the output power to the power receiving side coil in a contactless manner by applying the AC voltage. The power correction circuit is electrically connected between at least one of the pair of output points and the power feeding side coil, and has an adjustment capacitor and a plurality of adjustment switch elements. The power correction circuit charges and discharges the adjustment capacitor by switching the plurality of adjustment switch elements. The inverter circuit operates in a delay mode in which the current phase is delayed with respect to the voltage phase. The control process controls the plurality of conversion switch elements with a first drive signal, and controls the plurality of adjustment switch elements with a second drive signal. The control process adjusts the magnitude of the output power by adjusting a first phase difference that is a phase delay of the second drive signal with respect to the first drive signal. In the acquisition process, the adjustment capacitor is charged in one cycle of the second drive signal using the second phase difference which is a phase delay of the current flowing through the power feeding side coil with respect to the output voltage of the inverter circuit. The first phase difference at which the time is equal to the time when the adjustment capacitor is discharged is acquired as the power control start angle. The control process adjusts the magnitude of the output power by adjusting the first phase difference within a range equal to or smaller than the power control start angle. The second phase difference is a delay in the phase of the current flowing through the power feeding side coil with respect to the output voltage of the inverter circuit.

  According to the present invention, even if the relative positional relationship between the power feeding side coil and the power receiving side coil changes, it becomes easy to secure the necessary power in a short time.

FIG. 1 is a circuit diagram showing a contactless power transmission system according to an embodiment of the present invention. FIG. 2 is a waveform diagram showing the first drive signal and the second drive signal of the contactless power supply device according to the embodiment of the present invention. FIG. 3 is a graph showing an example of resonance characteristics in the above contactless power feeding device. FIG. 4A and FIG. 4B are graphs showing examples of resonance characteristics in the contactless power supply device of the above. FIG. 5: is a graph which shows the example of the phase difference characteristic in the case of the initial phase delay in the non-contact electric power feeder same as the above. FIG. 6A is an explanatory diagram showing a first charging mode of the power correction circuit in the above contactless power supply device. FIG. 6B is an explanatory diagram showing the first discharge mode of the power correction circuit in the above contactless power supply device. FIG. 6C is an explanatory diagram showing a second charging mode of the power correction circuit in the above contactless power supply device. FIG. 6D is an explanatory diagram showing the second discharge mode of the power correction circuit in the above contactless power supply device. FIG. 7 is a waveform diagram of the first drive signal, the primary side current, and the second drive signal when the voltage-current phase difference in the contactless power supply device is 90 degrees. FIG. 8 is a waveform diagram of the first drive signal, the primary side current, and the second drive signal when the voltage-current phase difference in the contactless power supply device is 45 degrees. FIG. 9 is a flowchart showing output power control in the contactless power supply device of the above.

(Embodiment)
The contactless power supply device of the present embodiment supplies power to a load in a contactless manner. In the non-contact power feeding device, the primary side coil (power feeding side coil) of the non-contact power feeding device and the secondary side coil (power receiving side coil) of the load are electromagnetically coupled (at least one of electric field coupling and magnetic field coupling). In this state, power is transmitted from the primary coil to the secondary coil. Thereby, the contactless power supply device supplies power to the load. This type of non-contact power supply device constitutes a non-contact power transmission system together with a non-contact power receiving device provided in a load.

<Outline of non-contact power transmission system>
First, an outline of the contactless power transmission system will be described with reference to FIG.

  The contactless power transmission system 1 of the present embodiment includes a contactless power supply device 2 having a primary coil L1 and a contactless power receiver 3 having a secondary coil L2. The contactless power receiving device 3 is configured so that output power is supplied from the contactless power feeding device 2 in a contactless manner. Here, the output power is the power output from the contactless power supply device 2, and is supplied from the primary coil L1 to the secondary coil L2 in a contactless manner by applying an AC voltage to the primary coil L1. Power. In the present embodiment, the primary side coil L1 and the secondary side coil L2 are spiral type coils in which conductors are spirally wound on a plane.

  In this embodiment, a case where the non-contact power receiving device 3 is mounted on an electric vehicle as a load will be described as an example. The electric vehicle is a vehicle that includes the storage battery 4 and travels using the electric energy stored in the storage battery 4. The non-contact power receiving device 3 mounted on the electric vehicle is used as a charging device for the storage battery 4. Although an electric vehicle that is driven by a driving force generated by an electric motor will be described as an example of an electric vehicle, the electric vehicle is not limited to an electric vehicle and may be, for example, a two-wheeled vehicle (electric motorcycle) or an electric bicycle.

  The non-contact power supply device 2 charges the storage battery 4 of the electric vehicle by supplying electric power supplied from a commercial power supply (system power supply) or a power generation facility such as a solar power generation facility to the non-contact power receiving device 3. The power supplied to the non-contact power supply device 2 may be either AC power or DC power, but in the present embodiment, the non-contact power supply device 2 is electrically connected to the DC power supply 5 and is non-contact. A case where DC power is supplied to the power supply device 2 will be described as an example. When AC power is supplied to the contactless power supply device 2, the contactless power supply device 2 is provided with an AC / DC converter that converts AC into DC.

  The contactless power supply device 2 is installed in, for example, a commercial facility, a public facility, or a parking lot such as an apartment house. The non-contact power feeding device 2 has at least the primary coil L1 installed on the floor or the ground, and supplies electric power to the non-contact power receiving device 3 of the electric vehicle parked on the primary coil L1 in a non-contact manner. At this time, the secondary coil L2 of the non-contact power receiving device 3 is located above the primary coil L1 and is thus electromagnetically coupled to the primary coil L1 (at least one of electric field coupling and magnetic field coupling). . Therefore, the output power from the primary coil L1 is transmitted (transmitted) to the secondary coil L2. The primary coil L1 is not limited to the configuration installed so as to be exposed from the floor or the ground, and may be installed so as to be embedded in the floor or the ground.

  The non-contact power receiving device 3 has a secondary coil L2, a pair of secondary capacitors C21 and C22, a rectifier circuit 31, and a smoothing capacitor C2. The rectifier circuit 31 is composed of a diode bridge having a pair of AC input points and a pair of DC output points. One end of the secondary coil L2 is electrically connected to one AC input point of the rectifier circuit 31 via the first secondary capacitor C21, and the other end of the secondary coil L2 is connected to the second secondary coil L2. It is electrically connected to the other AC input point of the rectifier circuit 31 via the secondary-side capacitor C22. The smoothing capacitor C2 is electrically connected between the pair of DC output points of the rectifier circuit 31. Further, both ends of the smoothing capacitor C2 are electrically connected to the pair of output terminals T21 and T22. The storage battery 4 is electrically connected to the pair of output terminals T21 and T22.

  As a result, the non-contact power receiving device 3 rectifies the AC voltage generated between both ends of the secondary coil L2 by receiving the output power from the primary coil L1 of the non-contact power feeding device 2 in the secondary coil L2. It is rectified by the circuit 31 and further smoothed by the smoothing capacitor C2 to obtain a DC voltage. The non-contact power receiving device 3 outputs (applies) the DC voltage thus obtained to the storage battery 4 from the pair of output terminals T21 and T22.

  Here, in the present embodiment, the contactless power supply device 2 includes a power correction circuit 22 that forms a resonance circuit (hereinafter, referred to as “primary resonance circuit”) together with the primary coil L1, and a pair of primary capacitors C11 and C11. Equipped with C12. In addition, in the non-contact power receiving device 3, the secondary coil L2 constitutes a resonance circuit (hereinafter, referred to as “secondary resonance circuit”) together with the pair of secondary capacitors C21 and C22. The contactless power transfer system 1 of the present embodiment employs a magnetic field resonance method (magnetic resonance method) in which power is transferred by causing the primary side resonance circuit and the secondary side resonance circuit to resonate. That is, in the non-contact power transmission system 1, even when the primary side coil L1 and the secondary side coil L2 are relatively separated from each other, the primary side resonance circuit and the secondary side resonance circuit have the same resonance frequency. The output power of the contact power supply device 2 can be transmitted with high efficiency.

<Outline of contactless power supply>
Next, an outline of the contactless power supply device will be described with reference to FIG.

  The contactless power feeding device 2 of the present embodiment further includes an inverter circuit 21, a power correction circuit 22, and a control circuit 23 in addition to the primary coil L1.

  The inverter circuit 21 has a plurality of (here, four) conversion switch elements Q1 to Q4 electrically connected between the pair of input points 211 and 212 and the pair of output points 213 and 214. . The inverter circuit 21 converts the DC voltage applied to the pair of input points 211 and 212 into an AC voltage by switching the plurality of conversion switch elements Q1 to Q4, and outputs the AC voltage from the pair of output points 213 and 214.

  The primary coil L1 is electrically connected between the pair of output points 213 and 214, and supplies an output power to the secondary coil L2 in a contactless manner by applying an AC voltage.

  The power correction circuit 22 is electrically connected between the output point 213 and the primary side coil L1, and has an adjustment capacitor C1 and a plurality (four here) of adjustment switch elements Q5 to Q8. The power correction circuit 22 adjusts the charging time and the discharging time of the adjusting capacitor C1 by switching the plurality of adjusting switch elements Q5 to Q8. Then, the power correction circuit 22 adjusts the charging time and the discharging time of the adjustment capacitor C1 to adjust the phase difference of the current flowing through the primary coil L1 with respect to the output voltage of the inverter circuit 21 (voltage current phase difference, , VI phase difference) φ can be adjusted. Thereby, the magnitude of the output power transmitted from the primary resonance circuit to the secondary resonance circuit is adjusted. The capacity of the adjusting capacitor C1 is sufficiently larger than the capacities of the primary side capacitors C11 and C12. For example, the adjustment capacitor C1 is set to a capacitance of μF order, and the primary side capacitors C11 and C12 are set to a capacitance of nF order.

  The control circuit 23 is configured to adjust the magnitude of the output power by two methods of “frequency control” and “phase difference control”. The control circuit 23 controls the plurality of conversion switch elements Q1 to Q4 with the first drive signal, and controls the plurality of adjustment switch elements Q5 to Q8 with the second drive signal.

  The control circuit 23 performs frequency control for controlling the switching frequencies of the conversion switch elements Q1 to Q4 by adjusting the frequency of the first drive signal.

  Further, the control circuit 23 performs the phase difference control by adjusting the drive phase difference θ which is the phase delay of the second drive signal with respect to the first drive signal. Specifically, the control circuit 23 has an acquisition unit 231. The acquisition unit 231 acquires (calculates) the power control start angle according to the VI phase difference φ of the inverter circuit 21 when the inverter circuit 21 is in the lag mode when the power correction circuit 22 is disabled. Here, the power control start angle is a drive phase difference θ in which the time for which the adjustment capacitor C1 is charged and the time for which the adjustment capacitor C1 is discharged are equal in one cycle of the second drive signal. In other words, the electric power control start angle means that when the drive phase difference θ is gradually reduced from the maximum value of the drive phase difference θ in which the inverter circuit 21 is in the lag mode, the electric charge is accumulated in the adjustment capacitor C1. It is the angle to start. The power control start angle is a value within a predetermined specified range. Further, the “lag phase mode” is a mode in which the current phase is delayed (delayed) with respect to the voltage phase. The drive phase difference θ corresponds to the first phase difference, and the VI phase difference φ corresponds to the second phase difference.

  The control circuit 23 adjusts the drive phase difference θ within a range from the power control start angle to a predetermined value smaller than the power control start angle (lower limit value of the predetermined range), that is, less than or equal to the power control start angle, thereby increasing the output power. Adjust the height.

  The “input point” and the “output point” in the present embodiment may not have substance as components (terminals) for connecting electric wires and the like, and may be included in, for example, leads of electronic components or circuit boards. It may be a part of the conductor.

<Circuit configuration>
Next, a specific circuit configuration of the contactless power feeding device 2 of the present embodiment will be described with reference to FIG.

  The contactless power feeding device 2 of the present embodiment includes a pair of input terminals T11 and T12. The DC power supply 5 is electrically connected to the pair of input terminals T11 and T12.

  The inverter circuit 21 is a full-bridge inverter circuit in which four conversion switch elements Q1 to Q4 are full-bridge connected. That is, the inverter circuit 21 has a first arm and a second arm that are electrically connected in parallel between the pair of input points 211 and 212, and the first arm and the second arm have four conversion switches. It is composed of elements Q1 to Q4. The first arm comprises a series circuit of a (first) conversion switch element Q1 and a (second) conversion switch element Q2, and a second arm comprises a (third) conversion switch element Q3 and a (fourth) conversion switch element Q2. No.) conversion switch element Q4 in series circuit. The middle point of the first arm (connection point of the conversion switch elements Q1, Q2) and the middle point of the second arm (connection point of the conversion switch elements Q3, Q4) become a pair of output points 213, 214. In the present embodiment, each of the four conversion switch elements Q1 to Q4 is an n-channel depletion type MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

  More specifically, the pair of input points 211 and 212 have a pair of inputs such that the first input point 211 is on the positive side of the DC power supply 5 and the second input point 212 is on the negative side of the DC power supply 5. It is electrically connected to the terminals T11 and T12. The drains of the conversion switch elements Q1 and Q3 are electrically connected to the first input point 211. The sources of the conversion switch elements Q2 and Q4 are electrically connected to the second input point 212. The connection point between the source of the conversion switch element Q1 and the drain of the conversion switch element Q2 becomes the first output point 213 of the inverter circuit 21. Further, the connection point between the source of the conversion switch element Q3 and the drain of the conversion switch element Q4 becomes the second output point 214 of the inverter circuit 21.

  Four diodes D1 to D4 are electrically connected between the drains and sources of the four conversion switch elements Q1 to Q4 so as to correspond to the four conversion switch elements Q1 to Q4 in a one-to-one relationship. . The diodes D1 to D4 are connected in a direction in which the drain side of each conversion switch element Q1 to Q4 is the cathode. Here, the diodes D1 to D4 are parasitic diodes of the conversion switch elements Q1 to Q4.

  The power correction circuit 22 has an adjusting capacitor C1 and four adjusting switch elements Q5 to Q8. The power correction circuit 22 has a third arm and a fourth arm that are electrically connected in parallel between the pair of output points 213 and 214 of the inverter circuit 21, and the third arm and the fourth arm are four. The adjusting switch elements Q5 to Q8 are included. The third arm is composed of a series circuit of a (first) adjusting switch element Q5 and a (third) adjusting switch element Q7, and a fourth arm is composed of a (second) adjusting switch element Q6 and a (second) adjusting switch element Q7. No.) A switching circuit Q8 for adjustment. Between the middle point of the third arm (connection point of the adjustment switch elements Q5 and Q7) and the middle point of the fourth arm (connection point of the adjustment switch elements Q6 and Q8), the adjustment capacitor C1 is electrically connected. Connected to each other. In the present embodiment, each of the four adjustment switch elements Q5 to Q8 is an n-channel depletion type MOSFET.

  More specifically, the source of the adjustment switch element Q5 and the drain of the adjustment switch element Q6 are electrically connected to the first output point 213 of the inverter circuit 21 via the first primary side capacitor C11. ing. The source of the adjustment switch element Q7 and the drain of the adjustment switch element Q8 are electrically connected to the second output point 214 via the second primary side capacitor C12 and the primary side coil L1. . Then, one end of the adjusting capacitor C1 is electrically connected to a connection point between the drain of the adjusting switch element Q5 and the drain of the adjusting switch element Q7. The other end of the adjusting capacitor C1 is electrically connected to a connection point between the source of the adjusting switch element Q6 and the source of the adjusting switch element Q8.

  Four diodes D5 to D8 are electrically connected between the drains and sources of the four adjustment switch elements Q5 to Q8 so as to correspond to the four adjustment switch elements Q5 to Q8 in a one-to-one correspondence. . The diodes D5 to D8 are connected in a direction in which the drain side of each of the adjustment switch elements Q5 to Q8 is the cathode. Here, the diodes D5 to D8 are parasitic diodes of the adjustment switch elements Q5 to Q8.

  The control circuit 23 includes, for example, a microcomputer as a main component. The microcomputer realizes a function as a control circuit (control unit) 23 by executing a program recorded in the memory of the microcomputer with a CPU (Central Processing Unit). The program may be recorded in advance in the memory of the microcomputer, may be recorded in a recording medium such as a memory card and provided, or may be provided through an electric communication line. In the present embodiment, the control circuit 23 has a control unit 232 in addition to the acquisition unit 231. In other words, the program is a program for causing a computer (here, a microcomputer) used in the contactless power supply device 2 to function as the acquisition unit 231 and the control unit 232.

  The controller 232 outputs the first drive signals G1 to G4 for switching on / off of the conversion switch elements Q1 to Q4 of the inverter circuit 21. The four first drive signals G1 to G4 correspond to the four conversion switch elements Q1 to Q4 on a one-to-one basis. Here, the control unit 232 controls the corresponding conversion switch elements Q1 to Q4 by outputting the first drive signals G1 to G4 to the gates of the corresponding conversion switch elements Q1 to Q4, respectively. .

  The control unit 232 also outputs second drive signals G5 to G8 for switching on and off of each of the four adjustment switch elements Q5 to Q8 of the power correction circuit 22. The four second drive signals G5 to G8 correspond one-to-one to the four adjustment switch elements Q5 to Q8. Here, the control unit 232 controls the corresponding adjustment switch elements Q5 to Q8 by outputting the second drive signals G5 to G8 to the gates of the corresponding adjustment switch elements Q5 to Q8, respectively. .

  In the present embodiment, the control unit 232 of the control circuit 23 supplies the first drive signals G1 to G4 and the second drive signal to the gates of the conversion switch elements Q1 to Q4 and the adjustment switch elements Q5 to Q8, respectively. Although G5 to G8 are directly output, the configuration is not limited to this. For example, the contactless power supply device 2 further includes a drive circuit, and the drive circuit receives the first drive signals G1 to G4 and the second drive signals G5 to G8 from the control unit 232 of the control circuit 23, and the conversion switch element. You may drive Q1-Q4 and the switch elements Q5-Q8 for adjustment.

  The primary side coil L1 is electrically connected in series with the pair of primary side capacitors C11 and C12 and the power correction circuit 22 between the pair of output points 213 and 214 of the inverter circuit 21. One end of the primary coil L1 is electrically connected to the first output point 213 of the inverter circuit 21 via the power correction circuit 22 and the first primary capacitor C11. The other end of the primary coil L1 is electrically connected to the second output point 214 of the inverter circuit 21 via the second primary capacitor C12.

  The contactless power supply device 2 of the present embodiment further includes a measurement unit 24 that measures the magnitude of the current flowing through the primary coil L1 as a measurement value. A current sensor 25 including, for example, a current transformer is provided between the primary coil L1 and the second primary capacitor C12. The measuring unit 24 receives the output of the current sensor 25 and measures the magnitude of the current flowing through the primary coil L1 as a measurement value. The measuring unit 24 is configured to output the measured value to the control circuit 23. The control circuit 23 monitors the magnitude of the output power output from the primary coil L1 and the phase of the current flowing through the primary coil L1, using the measurement values measured by the measurement unit 24.

<Basic operation>
Next, the basic operation of the contactless power supply device 2 of the present embodiment will be described with reference to FIGS. 1 and 2. In FIG. 2, the horizontal axis is the time axis, and the signal waveforms of the first drive signals “G1, G4”, “G2, G3”, the second drive signals “G5, G8”, “G6, G7” are shown in order from the top. ing. Note that “on” and “off” in FIG. 2 represent on and off of the corresponding switch elements (conversion switch element, adjustment switch element).

(1) No Power Correction Circuit Here, first, when the power correction circuit 22 is not provided, that is, between the pair of output points 213 and 214, only the primary coil L1 and the pair of primary capacitors C11 and C12 are electrically connected. The operation of the non-contact power feeding device 2 will be described on the assumption that the above situation occurs. The operation of the contactless power feeding device 2 at this time is such that, in the circuit configuration of FIG. 1, when the power correction circuit 22 is stopped, that is, all the adjustment switch elements Q5 to Q8 of the power correction circuit 22 are turned on. This is equivalent to the operation of the contactless power feeding device 2 when it is fixed. Further, it can be said that the case where the power correction circuit 22 stops operating is the case where the power correction circuit 22 is disabled.

  As shown in FIG. 2, the control unit 232 of the control circuit 23 includes the first drive signals G1 and G4 corresponding to the conversion switch elements Q1 and Q4 and the first drive signal G2 corresponding to the conversion switch elements Q2 and Q3. , G3, signals having mutually opposite phases (phase difference of 180 degrees) are generated. Thus, in the inverter circuit 21, a pair of the first conversion switch element Q1 and the fourth conversion switch element Q4, and a pair of the second conversion switch element Q2 and the third conversion switch element Q3. Are controlled to turn on alternately.

  As a result, a voltage (AC voltage) whose polarity (positive / negative) is periodically inverted is generated between the pair of output points 213 and 214 of the inverter circuit 21. In short, the inverter circuit 21 converts the DC voltage applied to the pair of input points 211 and 212 into an AC voltage by switching the plurality of conversion switch elements Q1 to Q4, and outputs the AC voltage from the pair of output points 213 and 214. . Below, regarding the output voltage of the inverter circuit 21, the voltage at which the first output point 213 of the pair of output points 213, 214 is at high potential is referred to as “positive polarity”, and the second output point 214 is at high potential. The voltage at which it becomes is called “negative polarity”. That is, the output voltage of the inverter circuit 21 has a positive polarity when the conversion switch elements Q1 and Q4 are on, and has a negative polarity when the conversion switch elements Q2 and Q3 are on.

  In this way, the inverter circuit 21 outputs the AC voltage from the pair of output points 213 and 214, so that the AC current flows in the primary side coil L1 electrically connected between the pair of output points 213 and 214, and the primary coil The side coil L1 generates a magnetic field. Thereby, the non-contact power feeding device 2 can supply the output power to the secondary coil L2 of the non-contact power receiving device 3 in a non-contact manner from the primary coil L1.

  By the way, when the power correction circuit 22 is not provided, in the contactless power supply device 2 of the present embodiment, the primary coil L1 constitutes a primary resonance circuit together with the pair of primary capacitors C11 and C12. Therefore, the magnitude of the output power output from the primary side coil L1 changes according to the operating frequency of the inverter circuit 21 (that is, the frequencies of the first drive signals Q1 to Q4), and the operating frequency of the inverter circuit 21 changes. It peaks when it matches the resonant frequency of the resonant circuit.

  Here, if the relative positional relationship between the primary side coil L1 and the secondary side coil L2 changes and the coupling coefficient between the primary side coil L1 and the secondary side coil L2 changes, the non-contact power feeding device 2 The frequency characteristic of the output power (hereinafter, referred to as “resonance characteristic”) changes. FIG. 3 shows changes in the resonance characteristics of the contactless power supply device 2 when the relative positional relationship between the primary coil L1 and the secondary coil L2 changes. In FIG. 3, the horizontal axis represents the frequency (the operating frequency of the inverter circuit 21) and the vertical axis represents the output power of the contactless power supply device 2, and the relative positional relationship between the primary coil L1 and the secondary coil L2 is shown. The resonance characteristics of the contactless power supply device 2 when different are shown by "X1" and "X2".

  Here, as shown in FIG. 3, it is assumed that the frequency band that can be used as the operating frequency of the inverter circuit 21 (hereinafter, referred to as “permitted frequency band F1”) is limited. The permitted frequency band F1 is defined by a law such as the Radio Law. In this case, frequencies below the lower limit value fmin and above the upper limit value fmax of the permitted frequency band F1 cannot be used as the operating frequency of the inverter circuit 21. In such a case, if the resonance characteristic of the non-contact power feeding device 2 is in a state as shown by “X1” in FIG. 3, for example, the output of the non-contact power feeding device 2 will be obtained no matter how the operating frequency of the inverter circuit 21 is adjusted. There is a possibility that the power will not reach the required level (hereinafter referred to as the "target value").

  For example, as shown in FIG. 4A, when the resonance frequency fr0 of the primary side resonance circuit is out of the permitted frequency band F1, the magnitude of the output power of the contactless power supply device 2 does not reach the peak, and as a result, the target value is reached. The output power may be insufficient with respect to P1. Further, for example, as shown in FIG. 4B, even when the resonance frequency fr0 of the primary side resonance circuit is within the permitted frequency band F1, the peak of the output power of the contactless power supply device 2 does not reach the target value P1, and as a result, The output power may be insufficient with respect to the target value P1. That is, in the example of FIGS. 4A and 4B, the electric power in the hatched (hatched) portion is insufficient with respect to the target value P1.

  Therefore, the contactless power supply device 2 of the present embodiment is provided with the power correction circuit 22 to adjust the charging time and the discharging time of the adjustment capacitor C1 to adjust the magnitude of the output power so as to satisfy the target value P1. It has the function of correction (adjustment). The load periodically determines whether or not the target value is changed according to the state of charge of the storage battery 4. When it is determined that the load should be changed, a target value according to the state of charge of the storage battery 4 is output to the contactless power supply device 2.

(2) With Power Correction Circuit Next, when the power correction circuit 22 is provided as shown in FIG. 1, that is, between the pair of output points 213 and 214, the primary side coil L1, the pair of primary side capacitors C11 and C12, and The operation of the contactless power supply device 2 when the power correction circuit 22 is electrically connected will be described.

  As shown in FIG. 2, the control unit 232 of the control circuit 23 includes the second drive signals G6 and G7 corresponding to the adjustment switch elements Q6 and Q7 and the second drive signal G5 corresponding to the adjustment switch elements Q5 and Q8. , G8, signals having mutually opposite phases (phase difference of 180 degrees) are generated. As a result, in the power correction circuit 22, a pair of the second adjusting switch element Q6 and the third adjusting switch element Q7 and a pair of the first adjusting switch element Q5 and the fourth adjusting switch element Q8. And are controlled to turn on alternately. In the present embodiment, the control unit 232 of the control circuit 23 sets the frequencies of the first drive signals G1 to G4 and the second drive signals G5 to G8 to the same frequency when executing the phase control.

  In the contactless power supply device 2 of the present embodiment, the power correction circuit 22 adjusts the charging time and the discharging time of the adjusting capacitor C1 to adjust the VI phase difference φ of the inverter circuit 21. As a result, when the output power of the contactless power supply device 2 is insufficient with respect to the target value P1, the power correction circuit 22 adjusts (corrects) the magnitude of the output power so as to satisfy the target value P1. Is possible.

  By the way, in the present embodiment, as described above, the first drive signals G1 and G4 corresponding to the conversion switch elements Q1 and Q4 and the first drive signals G2 and G3 corresponding to the conversion switch elements Q2 and Q3 are The signals have mutually opposite phases (phase difference of 180 degrees). Similarly, the second drive signals G6 and G7 corresponding to the adjustment switch elements Q6 and Q7 and the second drive signals G5 and G8 corresponding to the adjustment switch elements Q5 and Q8 have opposite phases (a phase difference of 180 degrees). Signal of.

  Here, the drive phase difference θ between the first drive signal and the second drive signal in the present embodiment is the delay of the phase of the second drive signals G6 and G7 with respect to the first drive signals G1 and G4, or the first drive signal. This is a phase delay of the second drive signals G5 and G8 with respect to G2 and G3 (see FIG. 2). That is, there is a difference of 180 degrees between the phase delay of the second drive signals G6 and G7 with respect to the first drive signals G1 and G4 and the phase delay of the second drive signals G5 and G8 with respect to the first drive signals G1 and G4. Therefore, the value of the drive phase difference θ differs depending on which phase delay is used as the drive phase difference θ. Therefore, in the present embodiment, the phase delay of the second drive signals G6 and G7 with respect to the first drive signals G1 and G4 or the phase delay of the second drive signals G5 and G8 with respect to the first drive signals G2 and G3 is set as the drive position. It is defined as the phase difference θ. In addition, as described above, the drive phase difference θ corresponds to the first phase difference.

<Slow phase mode>
Next, the delay mode will be described. The slow phase mode is a mode in which the output of the inverter circuit 21 has a delayed current phase (slow phase) with respect to the voltage phase.

(1) Without Power Correction Circuit Here, first, as in the case of the “basic operation” above, when the power correction circuit 22 is not provided, that is, between the pair of output points 213 and 214, the primary coil L1 and the pair of primary sides are provided. A case where only the capacitors C11 and C12 are electrically connected will be described.

  In this case, the inverter circuit 21 operates in the delay mode according to the relationship between the operating frequency of the inverter circuit 21 and the resonance frequency of the primary side resonance circuit, for example.

  The lag phase mode is a mode in which the inverter circuit 21 operates in a state in which the phase of the output current of the inverter circuit 21 (current flowing through the primary coil L1) is delayed from the phase of the output voltage of the inverter circuit 21. That is, in the slow phase mode, the current phase is delayed (slow) with respect to the voltage phase. In the lag mode, the switching operation of the inverter circuit 21 is soft switching. Therefore, in the lag mode, the switching loss of the conversion switching elements Q1 to Q4 can be reduced, and stress is less likely to be applied to the conversion switching elements Q1 to Q4. On the other hand, in the phase advance mode in which the inverter circuit 21 operates in a state where the phase of the output current of the inverter circuit 21 leads the phase of the output voltage of the inverter circuit 21, the switching loss of the conversion switch elements Q1 to Q4 increases. Cheap. In the phase advance mode, stress is likely to be applied to the conversion switch elements Q1 to Q4. Therefore, the inverter circuit 21 preferably operates in the lag mode rather than the phase advance mode. In this embodiment, the inverter circuit 21 is controlled so as to operate in the lag mode. At this time, the VI phase difference φ has a value within the range of 0 degrees to 90 degrees. In addition, as described above, the VI phase difference φ corresponds to the first phase difference.

(2) With power correction circuit Next, when there is the power correction circuit 22, that is, between the pair of output points 213 and 214, the primary side coil L1, the pair of primary side capacitors C11 and C12, and the power correction circuit 22 are electrically connected. The case where they are connected physically will be described.

  Like the inverter circuit 21, the power correction circuit 22 can operate in either an advanced mode or a delayed mode. However, it is preferable that the power correction circuit 22 also operates in the lag mode instead of the lag mode. Therefore, in the present embodiment, the power correction circuit 22 is configured to operate in the delay mode, like the inverter circuit 21.

  FIG. 5 shows the characteristic (phase difference characteristic) of the output power of the contactless power supply device 2 with respect to the drive phase difference θ when the inverter circuit 21 is in the lag mode without the power correction circuit 22. In FIG. 5, the horizontal axis represents the drive phase difference θ between the first drive signals G1 to G4 and the second drive signals G5 to G8, and the vertical axis represents the output power of the non-contact power supply device 2.

  On the other hand, when the inverter circuit 21 is in the lag mode (hereinafter, referred to as “initial lag”) without the power correction circuit 22, the output power of the contactless power feeder 2 is as shown in FIG. 5, for example. It changes according to the drive phase difference θ. In the example of FIG. 5, the output power of the contactless power supply device 2 is maximized and maximized when the drive phase difference θ is 270 degrees, and is minimized and minimized when the drive phase difference θ is 180 degrees. It changes depending on the phase difference θ. In the case of the initial phase lag, both the inverter circuit 21 and the power correction circuit 22 operate in the phase lag mode when the drive phase difference θ is 0 degrees to 90 degrees and 270 degrees to 360 degrees. That is, there are two sections, namely, a first section Z1 and a fourth section Z4 among the first section Z1 to the fourth section Z4 shown in FIG. In the first section Z1 shown in FIG. 5, the output power hardly changes even if the drive phase difference θ changes. Therefore, in the present embodiment, the range of the fourth section Z4, that is, the range of 270 degrees to 360 degrees is set as the specified range.

<Output power control>
Next, the operation of the “output power control” for adjusting the magnitude of the output power in the contactless power supply device 2 of the present embodiment will be described.

(1) Frequency Control and Phase Difference Control In the present embodiment, the control unit 232 of the control circuit 23 performs “frequency control” for adjusting the frequencies of the first drive signals G1 to G4 and the second drive signals G5 to G8, and driving. It is configured to adjust the magnitude of the output power by two methods of "phase difference control" for adjusting the phase difference θ.

  In the present embodiment, the control unit 232 of the control circuit 23 first performs frequency control for adjusting the magnitude of output power by adjusting the frequencies of the first drive signals G1 to G4.

  In the frequency control, the control unit 232 adjusts the magnitude of the output power by adjusting the frequencies of the first drive signals G1 to G4. That is, as described in the section “(1) No power correction circuit” in the above “basic operation”, the magnitude of the output power output from the primary coil L1 depends on the operating frequency of the inverter circuit 21 (that is, the first operation). It changes according to the frequencies of the drive signals Q1 to Q4 (see FIG. 3). Therefore, in frequency control, the control unit 232 of the control circuit 23 adjusts the operating frequency of the inverter circuit 21 by adjusting the frequencies of the first drive signals G1 to G4, and adjusts the magnitude of output power. In other words, the control unit 232 can control the VI phase difference φ and adjust the magnitude of the output power in frequency control. In this case, the power correction circuit 22 is in the invalid state (stop state).

  Here, when the frequency band (permitted frequency band F1) that can be used as the operating frequency of the inverter circuit 21 is limited, the frequency that can be adjusted by frequency control is limited to within the permissible frequency band F1.

  Then, when the magnitude of the output power adjusted by the frequency control is less than the predetermined target value, the control circuit 23 performs the phase difference control described below. That is, when the output power is insufficient with respect to the target value only by the frequency control, the control circuit 23 compensates the shortage by the phase difference control.

  The control circuit 23 first sets the drive phase difference θ to 360 degrees and starts the power correction circuit 22.

  The acquisition unit 231 of the control circuit 23 acquires, as the power control start angle, the drive phase difference θ that is a value (angle) within the specified range according to the VI phase difference φ. The control unit 232 controls the phase of the second drive signals G6, G7 (G5, G8) with respect to the first drive signals G1, G4 (G2, G3) in the range from the power control start angle to the minimum value (270) in the specified range. The magnitude of the output power is adjusted by adjusting the drive phase difference θ which is the delay of.

  Here, the power control start angle corresponds to the drive phase difference θ at which electric charge starts to be accumulated in the capacitor C1 when the drive phase difference θ is gradually reduced from 360 degrees. Therefore, the mathematical formula 1 “360 (degrees) −power control start angle + VI phase difference = 90 (degrees)” is established. That is, the acquisition unit 232 calculates (acquires) the power control start angle by using Expression 2 “power control start angle = VI phase difference φ + 270 (degrees)”.

  The control unit 232 adjusts the drive phase difference θ in the range from the power control start angle to a predetermined value (here, the lower limit value (270 degrees) of the specified range) with the acquired power control start angle as an initial value. Thus, the magnitude of the output power of the contactless power feeding device 2 is adjusted. The power control start angle is an angle that belongs to the specified range (270 degrees to 360 degrees). In the present embodiment, the lower limit value (270 degrees) of the specified range is set as the predetermined value, but it does not necessarily have to be the lower limit value. For example, the predetermined value may be another value (for example, 271) in consideration of the error of the output power.

  As is apparent from FIG. 5, the output power of the non-contact power supply device 2 changes according to the drive phase difference θ, and thus the control unit 232 adjusts the drive phase difference θ to a set value to control the magnitude of the output power. Adjustment is possible. Specifically, the control unit 232 uses the power control start angle as an initial value and gradually decreases the drive phase difference θ from the power control start angle to the lower limit value (270 degrees) of the specified range. Thereby, as the control circuit 23 gradually changes (decreases) the set value within the specified range, the output power of the contactless power supply device 2 gradually increases.

  In the present embodiment, the frequency during the phase difference control has the same value as the frequency after the adjustment by the frequency control. In short, during the phase difference control, the control unit 232 fixes the frequency to the final frequency adjusted by the frequency control.

(2) Principle of Output Power Control by Phase Difference Control Hereinafter, the control circuit 23 adjusts the drive phase difference θ to a set value within a specified range by the phase difference control, so that the output power of the contactless power supply device 2 is increased. The principle by which the length is adjusted will be described with reference to FIGS. 6A to 8.

  In the phase difference control, the control circuit 23 changes the balance between charging and discharging of the adjustment capacitor C1 by adjusting the drive phase difference θ, and changes the VI phase difference φ of the inverter circuit 21. Then, the output power of the contactless power feeding device 2 is adjusted by the VI phase difference φ of the inverter circuit 21.

  Here, whether the adjustment capacitor C1 is charged or discharged is determined by on / off of the plurality of adjustment switch elements Q5 to Q8 and the direction of the output current of the inverter circuit 21. Since the output current of the inverter circuit 21 is a current flowing through the primary coil L1, it is hereinafter also referred to as “primary current I1”. The direction of the primary side current I1 flowing from the first output point 213 through the primary side capacitor C11, the power correction circuit 22, the primary side coil L1, and the primary side capacitor C12 to the second output point 214, that is, in FIG. The direction of the primary-side current I1 indicated by the arrow is referred to as "forward direction". The direction of the primary side current I1 flowing from the second output point 214 through the primary side capacitor C12, the primary side coil L1, the power correction circuit 22, and the primary side capacitor C11 to the first output point 213, that is, in FIG. The direction opposite to the primary side current I1 indicated by the arrow is referred to as "negative direction".

  6A to 6D show a combination pattern of ON / OFF of the plurality of adjustment switch elements Q5 to Q8 and the direction of the primary-side current I1. In FIGS. 6A to 6D, bold arrows represent current paths, and the adjustment switch elements circled with dotted lines represent ON-state elements.

  FIG. 6A shows the state of the power correction circuit 22 in which the adjustment switch elements Q6 and Q7 are on, the adjustment switch elements Q5 and Q8 are off, and the primary current I1 in the negative direction is flowing (hereinafter, "First charge mode"). FIG. 6B shows the state of the power correction circuit 22 in which the adjustment switch elements Q6 and Q7 are on, the adjustment switch elements Q5 and Q8 are off, and the positive primary current I1 flows (hereinafter, “First discharge mode”). FIG. 6C shows, as the state of the power correction circuit 22, a state in which the adjustment switch elements Q5 and Q8 are on, the adjustment switch elements Q6 and Q7 are off, and the primary current I1 in the positive direction is flowing (hereinafter, “Second charging mode”). FIG. 6D shows, as the state of the power correction circuit 22, a state in which the adjusting switch elements Q5 and Q8 are on, the adjusting switch elements Q6 and Q7 are off, and the primary current I1 in the negative direction flows (hereinafter, “Second discharge mode”). In the first charging mode shown in FIG. 6A and the second charging mode shown in FIG. 6C, the adjustment capacitor C1 is charged. On the other hand, the adjustment capacitor C1 is discharged in the first discharge mode shown in FIG. 6B and the second discharge mode shown in FIG. 6D.

  That is, when the drive phase difference θ is equal to the power control start angle, the time lengths of the first charge mode period and the first discharge mode period are equal. When the drive phase difference θ is equal to the power control start angle, the time lengths of the second charge mode period and the second discharge mode period are equal. Therefore, in this case, no charge is stored in the capacitor C1.

  Next, with reference to FIGS. 7 and 8, the relationship between the drive phase difference θ and the balance of charging and discharging of the adjustment capacitor C1 will be described. 7 and 8, the waveforms of the first drive signal "G1, G4", the primary-side current "I1", and the two types of second drive signals "G6, G7" are arranged in order from the top with the horizontal axis as the time axis. Is represented. The two types of second drive signals referred to here have different drive phase differences θ. Note that “on” and “off” in FIGS. 7 and 8 represent on and off of the corresponding switch elements (conversion switch element, adjustment switch element).

  FIG. 7 exemplifies a case where the VI phase difference φ in the case of “initial delay” is 90 degrees. At this time, the acquisition unit 231 acquires (calculates) the power control start angle (360 degrees (= 90 + 270)) using Expression 2 described above.

  In FIG. 7, as the waveforms of the two types of second drive signals “G6, G7”, the waveform when the drive phase difference θ is the power control start angle (360 degrees) and the drive phase difference θ is 320 degrees in order from the top. Represents the waveform of. Further, in FIG. 7, when the drive phase difference θ is 360 degrees (power control start angle), the period of the first charging mode is “Tca1”, the period of the first discharging mode is “Tda1”, and the second charging mode is The period is represented by "Tca2" and the period of the second discharge mode is represented by "Tda2". Similarly, when the drive phase difference θ is 320 degrees, the period of the first charging mode is “Tcb1”, the period of the first discharging mode is “Tdb1”, the period of the second charging mode is “Tcb2”, and the second discharging is performed. The mode period is represented by "Tdb2".

  As is apparent from FIG. 7, when the power control start angle is 360 degrees, the time during which the adjustment capacitor C1 is charged and the time during which the adjustment capacitor C1 is discharged are equal to one cycle of the second drive signal. Equal (balance). Hereinafter, the time during which the adjustment capacitor C1 is charged in one cycle of the second drive signal is referred to as the charging time. In addition, the time during which the adjustment capacitor C1 is discharged in one cycle of the second drive signal is referred to as the discharge time. For example, if the drive phase difference θ is 360 degrees, the total of “Tca1” and “Tca2” and the total of “Tda1” and “Tda2” have the same length. It should be noted that in one cycle of the second drive signal, the state in which the charging time of the adjusting capacitor C1 and the discharging time of the adjusting capacitor C1 are equal means that the difference between the charging time and the discharging time is within a predetermined value or less. Is equivalent to the equilibrium state.

  On the other hand, if the drive phase difference θ is 320 degrees, the charging time exceeds the discharging time in one cycle of the second drive signal. That is, if the drive phase difference θ is 320 degrees, the total of “Tcb1” and “Tcb2” becomes longer than the total of “Tdb1” and “Tdb2”.

  From the above, when the drive phase difference θ is gradually changed from 360 degrees to approach 270 degrees, the balance between the charging time and the discharging time is broken in one cycle of the second driving signal, and the charging time gradually occupies. The ratio will increase. In FIG. 7, for convenience of description, notation about changes in the VI phase difference φ is omitted, but in reality, when the drive phase difference θ changes, the VI phase difference φ also changes to an initial value as the drive phase difference θ changes. (Here, 90 degrees). That is, when the charging time exceeds the discharging time, a current flows into the adjusting capacitor C1, and the phase of this current advances 90 degrees with respect to the phase of the voltage across the adjusting capacitor C1. That is, the adjusting capacitor C1 functions as a phase advancing capacitor. Then, the VI phase difference φ decreases due to the current flowing into the adjustment capacitor C1, and the output power increases. That is, when the drive phase difference θ is smaller than the power control start angle, the VI phase difference φ can be reduced by the same angle as the change of the drive phase difference θ (the phase difference between the voltage and the current of the adjustment capacitor C1 is set to 90 degrees). To act to maintain). As a result, the output power of the non-contact power feeding apparatus 2 gradually increases as the drive phase difference θ approaches 270 degrees from the power control start angle.

  At this time, if the drive phase difference θ is reduced from the power control start angle, the VI phase difference φ is reduced so that the balance between the charging time and the discharging time is maintained. That is, even in the region where the drive phase difference θ is equal to or smaller than the power control start angle, the charging time and the discharging time are balanced. For example, if the relationship in which the charging time exceeds the discharging time is maintained, the adjustment capacitor C1 is continuously charged, and the voltage of the adjustment capacitor C1 diverges to infinity. However, in reality, when the VI phase difference φ becomes small, the charging time and the discharging time rebalance, and the voltage of the adjustment capacitor C1 does not diverge.

  Further, FIG. 8 exemplifies a case where the VI phase difference φ in the case of “initial delay” is 45 degrees. At this time, the acquisition unit 231 acquires (calculates) the power control start angle (315 degrees (= 45 + 270)) using Equation 1 “Power control start angle = VI phase difference φ + 270 degrees”.

  In FIG. 8, as the waveforms of the two types of second drive signals “G6, G7”, the waveforms when the drive phase difference θ is the power control start angle (315 degrees) and the drive phase difference θ is 290 degrees in order from the top. Represents the waveform of. Further, in FIG. 8, when the drive phase difference θ is 315 degrees (power control start angle), the period of the first charging mode is “Tca1”, the period of the first discharging mode is “Tda1”, and the second charging mode is The period is represented by "Tca2" and the period of the second discharge mode is represented by "Tda2". Similarly, when the drive phase difference θ is 290 degrees, the period of the first charging mode is “Tcb1”, the period of the first discharging mode is “Tdb1”, the period of the second charging mode is “Tcb2”, and the second discharging is performed. The mode period is represented by "Tdb2".

  If the VI phase difference φ is 45 degrees, as is apparent from FIG. 8, even if the drive phase difference θ is 315 degrees, the charging time and the discharging time are equal in one cycle of the second drive signal ( Balance). That is, even if the drive phase difference θ is 315 degrees, the total of “Tca1” and “Tca2” and the total of “Tda1” and “Tda2” have the same length. On the other hand, if the drive phase difference θ is 290 degrees, the charging time exceeds the discharging time in one cycle of the second drive signal. That is, when the drive phase difference θ is 290 degrees, the total of “Tcb1” and “Tcb2” is longer than the total of “Tdb1” and “Tdb2”.

  From the above, not only in the case where the VI phase difference φ is 90 degrees but also in the case of “initial delay”, when the drive phase difference θ changes from the power start angle to approach 270 degrees, the second drive signal 1 In the cycle, the balance between the charging time and the discharging time is broken, and the proportion of the charging time gradually increases. However, as described above, in order to ensure the balance between the charging time and the discharging time, the VI phase difference φ decreases, and the charging time and the discharging time balance again.

  Here, when the drive phase difference θ is gradually reduced from 360 degrees, the drive phase difference θ corresponding to the inflection point at which the balance between the charging time and the discharging time is broken and the voltage across the adjustment capacitor C1 starts to rise. (Power control start point) differs depending on the VI phase difference φ. The change start point shifts closer to 270 degrees when the VI phase difference φ is 45 degrees than when it is 90 degrees, that is, as the VI phase difference φ is smaller.

  That is, in the case of “initial delay”, the power control start point exists within the specified range (for example, 270 degrees to 360 degrees) even if there is a difference due to the VI phase difference φ. Therefore, if the control circuit 23 gradually decreases the drive phase difference θ from the upper limit value (360 degrees) to the lower limit value (270 degrees) of the specified range, after the drive phase difference θ reaches the power control start point, The output power of the contactless power feeding device 2 gradually increases. However, since the output power of the contactless power supply device 2 does not change until the drive phase difference θ reaches the power control start angle from the upper limit value (360 degrees) of the specified range, the control circuit 23 outputs the output power during this period. The amount of power cannot be adjusted.

  In view of this, in the present embodiment, the acquisition unit 231 acquires (calculates) the drive phase difference θ as the power control start angle at which the voltage across the adjustment capacitor C1 begins to rise, using Equation 2 above. The control unit 232 adjusts the magnitude of the output power by gradually changing the obtained power control start point to the lower limit value of the specified range from the power control start point as an initial value. As a result, the control unit 232 can adjust the magnitude of the output power more quickly than in the case where the upper limit value of the specified range (270 degrees to 360 degrees) is gradually changed.

(3) Flow of Output Power Control The flow of “output power control” of the present embodiment will be described below with reference to the flowchart of FIG. 9 showing the process of the control circuit 23. Note that, here, the phase difference control processing of the frequency control and the phase difference control performed by the control circuit 23 will be described.

  When the control circuit 23 sets the drive phase difference θ to 360 degrees and starts the power correction circuit 22, the acquisition unit 231 of the control circuit 23 acquires the VI phase difference φ (step S1). The acquisition unit 231 acquires the power control start angle using the VI phase difference φ (step S2). Specifically, the acquisition unit 231 adds the value “270” to the VI phase difference φ and sets the addition result as the power control start angle.

  The control circuit 23 sets the drive phase difference θ as the initial value of the acquired power control start angle (step S3).

  The control circuit 23 compares the magnitude of the output power at the drive phase difference θ with a predetermined target value (step S4). If the output power is within the allowable error range (± several%) of the target value (“rating” in step S4), the drive phase difference θ and the value at that time are fixed (step S5). The control circuit 23 terminates the process after executing step S5. Thereby, the electric power output from the primary coil L1 becomes equal to the target.

  On the other hand, if the output power is below the lower limit of the allowable error range of the target value (“insufficient” in step S4), the control circuit 23 determines that the drive phase difference θ and the lower limit value of the specified range (here, 270 degrees). Are compared (step S6). If the drive phase difference θ is greater than or equal to the lower limit value (“No” in step S6), the control circuit 23 decrements (θ−1) the drive phase difference θ (step S7) and returns to the process of step S4. By repeating these processes (steps S6 and S7), the control circuit 23 can gradually reduce the drive phase difference θ and gradually increase the output power. That is, the control circuit 23 can bring the magnitude of the output power close to a predetermined target value.

  When the drive phase difference θ is less than the lower limit value in the phase difference control (“Yes” in step S6), the control circuit 23 determines that there is an error (step S8) and ends the process.

  If the output power exceeds the upper limit of the allowable error range of the target value (“excess” in step S4), the control circuit 23 determines whether the voltage value of the capacitor C1 is “0” ( Step S9). If the voltage value of the capacitor C1 is larger than “0” (“No” in step S9), the control circuit 23 increments the drive phase difference θ (θ + 1) (step S10) and returns to the process of step S4. By repeating these processes (steps S9 and S10), the control circuit 23 can gradually increase the drive phase difference θ and gradually reduce the output power, that is, can approach the predetermined target value.

  When the voltage value of the capacitor C1 becomes “0” (“Yes” in step S9), the control circuit 23 determines that the drive phase difference θ has been increased to the power control start angle, and proceeds to step S8. After executing the process of step S8, the control circuit 23 suppresses the process by the power correction circuit 22 (the process of adjusting the magnitude of the output power). That is, the output power changes in the range from the lower limit value of the specified range to the power control start angle. When the drive phase difference θ is gradually increased to reach the power control start angle, the output power does not change even if the drive phase difference θ is increased thereafter. Therefore, when the drive phase difference θ is gradually increased to reach the power control start angle and the magnitude of the output power does not reach the predetermined target value, the control circuit 23 determines that there is an error. To do. As a result, the control circuit 23 can omit the phase difference control in the section where the output power does not change (the section from the power control start angle to the upper limit of the specified range). At this time, the control circuit 23 turns off the power correction circuit 22, that is, turns on all the adjustment switch elements Q5 to Q8 of the power correction circuit 22.

<Startup process>
The contactless power feeding device 2 of the present embodiment soft-starts the inverter circuit 21 as described below at the time of start-up when the inverter circuit 21 starts operating.

  When the inverter circuit 21 is activated, the control circuit 23 sets the duty ratio of the first drive signals G1 to G4 for controlling the conversion switch elements Q1 to Q4 from 0 (zero) to a predetermined value (for example, 0.5). By gradually raising, the soft start of the inverter circuit 21 is realized. Thereby, the sudden change of the voltage or current input to the non-contact power supply device 2 is suppressed, and the stress applied to the circuit element can be reduced. Hereinafter, the process in which the control circuit 23 changes the duty ratio of the first drive signals G1 to G4 and soft-starts the inverter circuit 21 in this manner is referred to as “starting process”.

  In the non-contact power supply device 2 of the present embodiment, while the control circuit 23 is performing the start-up process, with respect to the power correction circuit 22, all the adjustment switch elements Q5 to Q8 are fixed to be on, and the function of the power correction circuit 22 is fixed. Disable. As a result, the non-contact power feeding device 2 is in a state equivalent to “(1) No power correction circuit” (see the section “Basic operation” above).

  When the start-up process of the inverter circuit 21 is completed, that is, when the duty ratio of the first drive signals G1 to G4 reaches a predetermined value (for example, 0.5), the control circuit 23 starts adjusting the output power by frequency control. . At this time, the control circuit 23 maintains the adjustment switch elements Q5 to Q8 of the power correction circuit 22 in the ON state.

  Then, the control circuit 23 starts the operation of the power correction circuit 22 when the magnitude of the output power adjusted by the frequency control is less than the predetermined target value. Specifically, the control circuit 23 starts switching control of the adjustment switch elements Q5 to Q8 with the second drive signals G5 to G8. As a result, the contactless power supply device 2 is in a state equivalent to “(2) Power correction circuit provided” (see the section “Basic operation” above). At this time, it is preferable that the control circuit 23 once set the drive phase difference θ to 360 (degrees) and start the power correction circuit 22. Thereafter, the control circuit 23 sets the power control start angle acquired by the acquisition unit 231 as an initial value, gradually decreases the drive phase difference θ from the power control start angle, and adjusts the magnitude of the output power.

  According to this configuration, when the magnitude of the output power reaches the target value only by frequency control, the control circuit 23 does not start the power correction circuit 22, so that the efficiency (power conversion efficiency) of the power correction circuit 22 is reduced. You can avoid a decline.

  By the way, the control circuit 23 may be configured to start the operation of the power correction circuit 22 and adjust the output power by the phase difference control before adjusting the output power by the frequency control. That is, the control circuit 23 adjusts the output power by the phase difference control before performing the frequency control, and when the magnitude of the output power after the adjustment by the phase difference control is less than a predetermined target value, Frequency control may be performed.

<Search mode>
In the present embodiment, the control circuit 23 estimates the coupling coefficient between the primary side coil L1 and the secondary side coil L2 in addition to the normal mode (including the startup process) for performing the output power control as described above. It has a search mode to enable. The control circuit 23 executes the process in the search mode before performing the above-mentioned start-up process, frequency control, and phase difference control, that is, before operating in the normal mode, and performs a process between the primary side coil L1 and the secondary side coil L2. Estimate the coupling coefficient.

  Based on the coupling coefficient, the control circuit 23 uses the resonance characteristics (that is, the operating frequency of the inverter circuit 21 and the output of the contactless power supply device 2) as described in the section “(1) With power correction circuit” in the above “basic operation”. Power relationship) can be further estimated. As a result, the control circuit 23 can estimate the frequency range in which the inverter circuit 21 operates in the lag mode (that is, does not enter the phase advance mode) with respect to the operating frequency f1 of the inverter circuit 21, for example. As a result, the control circuit 23 can set the initial value of the operating frequency f1 when starting the operation in the normal mode within the frequency range in which the inverter circuit 21 operates in the lag mode. In this case, the lower limit value of the operating frequency f1 in the frequency control described above is the larger of the lower limit value of the frequency range in which the inverter circuit 21 operates in the lag mode and the lower limit value fmin of the permitted frequency band F1. .

<Modification>
In the present embodiment, the primary side coil L1 and the secondary side coil L2 may be solenoid type coils in which a conductive wire is spirally wound around a core.

  Further, the power correction circuit 22 is not limited to the configuration using the four adjustment switch elements Q5 to Q8 as in the present embodiment. The circuit for adjusting the magnitude of the output power may be a circuit having a function equivalent to that of the power correction circuit 22 shown in FIG.

  The load to which the output power is supplied (that is, is supplied) from the contactless power supply device 2 in a contactless manner is not limited to the electric vehicle, but includes, for example, an electric device including a storage battery such as a mobile phone or a smartphone, or a storage battery. It may be an electric device such as a lighting device.

  Further, the transmission method of the output power from the non-contact power feeding device 2 to the non-contact power receiving device 3 is not limited to the magnetic field resonance method described above, and may be, for example, an electromagnetic induction method or a microwave transmission method.

  Further, each of the conversion switching elements Q1 to Q4 and each of the adjustment switching elements Q5 to Q8 may be configured by another semiconductor switching element such as a bipolar transistor or an IGBT (Insulated Gate Bipolar Transistor).

  The diodes D1 to D4 are not limited to the parasitic diodes of the conversion switch elements Q1 to Q4, and may be externally attached to the conversion switch elements Q1 to Q4. Similarly, the diodes D5 to D8 are not limited to the parasitic diodes of the adjustment switch elements Q5 to Q8, but may be externally attached to the adjustment switch elements Q5 to Q8.

  The measurement unit 24 is not limited to the configuration provided separately from the control circuit 23, and may be provided integrally with the control circuit 23. Furthermore, since the measuring unit 24 only needs to be able to measure the magnitude of the current flowing through the primary coil L1, the current sensor 25 is not limited to being between the primary coil L1 and the second primary capacitor C12, but the primary coil L1. It suffices if it is on the path of the current flowing to the.

  The control unit 232 of the control circuit 23 does not necessarily have to perform frequency control, and may be configured to adjust the magnitude of output power only by phase difference control.

  Further, it is not essential that one control circuit 23 is provided with the acquisition unit 231 and the control unit 232. For example, the acquisition unit 231 may be provided separately from the control unit 232.

  The inverter circuit 21 may be a voltage-type inverter capable of converting a DC voltage into an AC voltage and outputting the AC voltage, and is not limited to a full-bridge inverter circuit in which four conversion switch elements Q1 to Q4 are full-bridge connected. The inverter circuit 21 may be, for example, a half bridge inverter circuit.

  Further, in the contactless power supply device 2, the power correction circuit 22 may be electrically connected between at least one of the output points 213 and 214 and the primary coil L1, and the output point 213 and the primary coil L1. , And may be electrically connected between the output point 214 and the primary coil L1.

  Further, in the contactless power supply device 2, the power correction circuit 22 is disabled when performing frequency control, but the power correction circuit 22 may be operated by setting the drive phase difference θ to 360 degrees as an initial value. Good. At this time, the first drive signals G1, G4 and the second drive signals G6, G7 change in a similar manner, and the first drive signals G2, G3 and the second drive signals G5, G8 synchronize in a similar manner. Change. Therefore, even if the power correction circuit 22 operates, no charge is stored in the adjustment capacitor C1.

<Summary>
As described above, the non-contact power feeding device 2 according to the first aspect of the present invention includes the inverter circuit 21, the power feeding side coil L1, the power correction circuit 22, and the control circuit 23. The inverter circuit 21 has a plurality of conversion switch elements Q1 to Q4 electrically connected between the pair of input points 211 and 212 and the pair of output points 213 and 214. The inverter circuit 21 converts the DC voltage applied to the pair of input points 211 and 212 into an AC voltage by switching the plurality of conversion switch elements Q1 to Q4, and outputs the AC voltage from the pair of output points 213 and 214. The power feeding side coil L1 is electrically connected between the pair of output points 213 and 214, and supplies output power to the power receiving side coil L2 in a contactless manner by applying an AC voltage. The power correction circuit 22 is electrically connected between at least one of the pair of output points 213 and 214 and the power feeding side coil L1 and includes an adjustment capacitor C1 and a plurality of adjustment switch elements Q5 to Q8. There is. The power correction circuit 22 charges and discharges the adjustment capacitor C1 by switching the plurality of adjustment switch elements Q5 to Q8. The control circuit 23 controls the plurality of conversion switch elements Q1 to Q4 with the first drive signals G1 to G4, and controls the plurality of adjustment switch elements Q5 to Q8 with the second drive signals G5 to G8. The inverter circuit 21 operates in a lag mode in which the current phase is delayed with respect to the voltage phase. The control circuit 23 adjusts a first phase difference (driving phase difference θ) which is a phase delay of the second driving signals G6, G7 (G5, G8) with respect to the first driving signals G1, G4 (G2, G3). Is configured to adjust the magnitude of the output power. The control circuit 23 uses the second phase difference (VI phase difference φ) to determine the time during which the adjustment capacitor C1 is charged in one cycle of the second drive signals G6, G7 (G5, G8) and the adjustment capacitor C1. The first phase difference at which the discharge time is equal is acquired as the power control start angle. The control circuit 23 adjusts the magnitude of the output power by adjusting the first phase difference at the power control start angle or less. The second phase difference is a delay in the phase of the current flowing through the power feeding side coil L1 with respect to the output voltage of the inverter circuit 21.

  According to this configuration, the contactless power supply device 2 adjusts the phase difference, which is the phase delay of the second drive signals G6, G7 (G5, G8) with respect to the first drive signals G1, G4 (G2, G3). , The output power can be adjusted. Therefore, even if the relative positional relationship between the primary coil L1 and the secondary coil L2 changes and the coupling coefficient between the primary coil L1 and the secondary coil L2 changes, the non-contact power feeding device With No. 2, it becomes easier to secure the necessary power by adjusting the phase difference. Moreover, the non-contact power feeding device 2 acquires the power control start angle, which is the angle at which the electric charge starts to accumulate in the adjustment capacitor C1, using the second phase difference. Since the contactless power supply device 2 adjusts the drive phase difference θ within a range from a predetermined value (for example, the lower limit value of the specified range) to the power control start angle, it becomes easy to secure necessary power in a short time.

  Further, in the non-contact power supply device 2 according to the second aspect of the present invention, in the first aspect, the control circuit 23 sets the power control start angle as an initial value and gradually reduces the first phase difference to output the power. Increase the power. With this configuration, the output power can be increased by gradually reducing the first phase difference.

  Further, in the non-contact power feeding apparatus 2 of the third aspect according to the present invention, in the first or second aspect, the control circuit 23 adds the second phase difference to the predetermined value to obtain the power control start angle. . According to this configuration, the non-contact power feeding apparatus 2 can acquire the power control start angle by adding a predetermined value to the second phase difference (VI phase difference φ).

  Moreover, in the non-contact power feeding apparatus 2 of the fourth aspect according to the present invention, in the third aspect, the predetermined value is 270 degrees. According to this configuration, the contactless power supply device 2 can narrow down the range for adjusting the magnitude of the output power from the specified range (270 degrees to 360 degrees).

  Further, in the non-contact power feeding apparatus 2 of the fifth aspect according to the present invention, in any one of the first to fourth aspects, the control circuit 23 controls the adjustment capacitor when the magnitude of the output power decreases. When the voltage of C1 becomes 0, the power correction circuit 22 is stopped. When the magnitude of the output power is decreasing, the contactless power feeding device 2 adjusts the drive phase difference θ to gradually lengthen the discharge period of the adjustment capacitor C1. When the voltage value of the adjustment capacitor C1 becomes 0, the charging period and the discharging period are the same, that is, the drive phase difference θ becomes the power control start angle. Then, the contactless power supply device 2 can omit the control in the section in which the output power does not change by suppressing the adjustment of the output power by the power correction circuit 22.

  Further, in the non-contact power feeding apparatus 2 of the sixth aspect according to the present invention, in any one of the first to fifth aspects, the power correction circuit 22 includes one of the pair of output points 213 and 214 and the power feeding side coil. It is electrically connected to L1. According to this configuration, the contactless power feeding device 2 adjusts the phase difference, which is the delay of the phase of the second drive signals G6, G7 (G5, G8) with respect to the first drive signals G1, G4 (G2, G3). , The output power can be adjusted.

  Moreover, the non-contact electric power transmission system 1 of the 7th aspect which concerns on this invention has the non-contact electric power feeding apparatus 2 of any one of the 1st-6th aspect, and the non-contact electric power receiving apparatus 3 which has the receiving side coil L2. Prepare The non-contact power receiving device 3 is configured such that output power is supplied from the non-contact power feeding device 2 to the power receiving side coil L2 in a non-contact manner. With this configuration, in the non-contact power transmission system 1, the non-contact power feeding device 2 can easily secure the necessary power in a short time even if the relative positional relationship between the power feeding side coil and the power receiving side coil changes. Become.

  The program according to the eighth aspect of the present invention causes a computer used in the contactless power supply device 2 to function as the control unit 232 and the acquisition unit 231. The contactless power supply device 2 includes an inverter circuit 21, a power supply side coil L1, and a power correction circuit 22. The inverter circuit 21 has a plurality of conversion switch elements Q1 to Q4 electrically connected between the pair of input points 211 and 212 and the pair of output points 213 and 214. The inverter circuit 21 converts the DC voltage applied to the pair of input points 211 and 212 into an AC voltage by switching the plurality of conversion switch elements Q1 to Q4, and outputs the AC voltage from the pair of output points 213 and 214. The power feeding side coil L1 is electrically connected between the pair of output points 213 and 214, and supplies output power to the power receiving side coil L2 in a contactless manner by applying an AC voltage. The power correction circuit 22 is electrically connected between the pair of output points 213 and 214 and the power feeding side coil L1, and has an adjustment capacitor C1 and a plurality of adjustment switch elements Q5 to Q8. The power correction circuit 22 charges and discharges the adjustment capacitor C1 by switching the plurality of adjustment switch elements Q5 to Q8. The inverter circuit 21 operates in the lag phase mode in which the current phase is delayed with respect to the voltage phase. The controller 232 controls the plurality of conversion switch elements Q1 to Q4 with the first drive signals G1 to G4, and controls the plurality of adjustment switch elements Q5 to Q8 with the second drive signals G5 to G8. The controller 232 adjusts a first phase difference (driving phase difference θ) that is a phase delay of the second driving signals G6, G7 (G5, G8) with respect to the first driving signals G1, G4 (G2, G3). Adjust the magnitude of output power. The acquisition unit 231 uses the second phase difference (VI phase difference φ) to determine the time during which the adjustment capacitor C1 is charged in one cycle of the second drive signals G6, G7 (G5, G8) and the adjustment capacitor C1. The first phase difference at which the discharge time is equal is acquired as the power control start angle. The control unit adjusts the magnitude of the output power by adjusting the first phase difference in the range of the power control start angle or less. The second phase difference is a delay in the phase of the current flowing through the power feeding side coil L1 with respect to the output voltage of the inverter circuit 21.

  According to this program, a function equivalent to that of the contactless power feeding device 2 of the present embodiment can be realized without using the dedicated control circuit 23, and the relative positional relationship between the power feeding side coil and the power receiving side coil changes. However, there is an advantage that it is easy to secure necessary power in a short time.

  A noncontact power feeding device control method according to a ninth aspect of the present invention includes a control process and an acquisition process. The contactless power supply device 2 includes an inverter circuit 21, a power supply side coil L1, and a power correction circuit 22. The inverter circuit 21 has a plurality of conversion switch elements Q1 to Q4 electrically connected between the pair of input points 211 and 212 and the pair of output points 213 and 214. The inverter circuit 21 converts the DC voltage applied to the pair of input points 211 and 212 into an AC voltage by switching the plurality of conversion switch elements Q1 to Q4, and outputs the AC voltage from the pair of output points 213 and 214. The power feeding side coil L1 is electrically connected between the pair of output points 213 and 214, and supplies output power to the power receiving side coil L2 in a contactless manner by applying an AC voltage. The power correction circuit 22 is electrically connected between the pair of output points 213 and 214 and the power feeding side coil L1, and has an adjustment capacitor C1 and a plurality of adjustment switch elements Q5 to Q8. The power correction circuit 22 charges and discharges the adjustment capacitor C1 by switching the plurality of adjustment switch elements Q5 to Q8. The inverter circuit 21 operates in the lag mode in which the current phase is delayed with respect to the voltage phase. In the control process, the first drive signals G1 to G4 control the plurality of conversion switch elements Q1 to Q4, and the second drive signals G5 to G8 control the plurality of adjustment switch elements Q5 to Q8. The control process is performed by adjusting the first phase difference (driving phase difference θ) which is the phase delay of the second driving signals G6, G7 (G5, G8) with respect to the first driving signals G1, G4 (G2, G3). , Adjust the output power. The acquisition process uses the second phase difference (VI phase difference φ) to charge the adjustment capacitor C1 in one cycle of the second drive signals G6, G7 (G5, G8) and discharge the adjustment capacitor C1. The first phase difference with which the time to be equalized is acquired as the power control start angle. The control process adjusts the magnitude of the output power by adjusting the first phase difference in the range of the power control start angle or less. The second phase difference is a delay in the phase of the current flowing through the power feeding side coil L1 with respect to the output voltage of the inverter circuit 21.

  According to this control method, it is possible to realize a function equivalent to that of the non-contact power feeding apparatus 2 of this embodiment without using the dedicated control circuit 23.

DESCRIPTION OF SYMBOLS 1 non-contact electric power transmission system 2 non-contact electric power feeding apparatus 3 non-contact electric power receiving apparatus 21 inverter circuits 211, 212 pair of input points 213, 214 pair of output points 22 power correction circuit 23 control circuit 231 acquisition section 232 control section C1 adjustment capacitor G1 to G4 first drive signal G5 to G8 second drive signal L1 primary side coil (power supply side coil)
L2 secondary coil (power receiving coil)
Q1-Q4 conversion switch element Q5-Q8 adjustment switch element θ Drive phase difference (first phase difference)
φ voltage current phase difference (VI phase, second phase difference)

Claims (9)

A plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points, the direct current applied to the pair of input points by switching of the plurality of conversion switch elements An inverter circuit that converts a voltage into an AC voltage and outputs the AC voltage from the pair of output points,
A power supply side coil that is electrically connected between the pair of output points and that supplies output power in a non-contact manner to the power receiving side coil by applying the AC voltage,
It is electrically connected between at least one of the pair of output points and the power supply side coil, has an adjusting capacitor and a plurality of adjusting switch elements, by switching of the plurality of adjusting switch elements, A power correction circuit that charges and discharges the adjustment capacitor,
A control circuit that controls the plurality of conversion switch elements with a first drive signal and controls the plurality of adjustment switch elements with a second drive signal;
The inverter circuit is operating in a lag mode in which the current phase is delayed with respect to the voltage phase,
The control circuit is configured to adjust the magnitude of the output power by adjusting a first phase difference which is a phase delay of the second drive signal with respect to the first drive signal,
The control circuit charges the adjustment capacitor in one cycle of the second drive signal by using a second phase difference which is a phase delay of a current flowing through the power feeding side coil with respect to an output voltage of the inverter circuit. The first phase difference at which the time and the time at which the adjustment capacitor is discharged is equal to each other is acquired as the power control start angle, and the first phase difference is adjusted within a range equal to or less than the power control start angle, whereby the output A contactless power supply device characterized by adjusting the amount of electric power. The contactless power supply device according to claim 1, wherein the control circuit gradually reduces the first phase difference and gradually increases the output power with the power control start angle as an initial value. . The control circuit is
The value obtained by adding the second phase difference to a predetermined value that is determined in advance is acquired as the power control start angle. The contactless power supply device according to claim 1 or 2. The contactless power supply device according to claim 3, wherein the predetermined value is 270 degrees. 5. The control circuit puts the power correction circuit into a stopped state when the voltage of the adjustment capacitor becomes 0 when the magnitude of the output power is decreasing. The contactless power feeding device according to any one of items 1 to 5. The non-contact according to any one of claims 1 to 5, wherein the power correction circuit is electrically connected between one of the pair of output points and the power feeding side coil. Power supply device. A contactless power supply device according to any one of claims 1 to 6,
A non-contact power receiving device having the power receiving side coil,
The contactless power receiving device is configured so that the output power is supplied from the contactless power feeding device to the power receiving side coil in a contactless manner. A plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points, the direct current applied to the pair of input points by switching of the plurality of conversion switch elements An inverter circuit that converts a voltage into an AC voltage and outputs the AC voltage from the pair of output points,
A power supply side coil that is electrically connected between the pair of output points and that supplies output power in a non-contact manner to the power receiving side coil by applying the AC voltage,
It is electrically connected between at least one of the pair of output points and the power supply side coil, has an adjusting capacitor and a plurality of adjusting switch elements, by switching of the plurality of adjusting switch elements, And a power correction circuit for charging and discharging the adjustment capacitor, the inverter circuit is a computer used for a non-contact power supply device that operates in a lag mode in which the current phase is delayed with respect to the voltage phase,
The first drive signal controls the plurality of conversion switch elements, the second drive signal controls the plurality of adjustment switch elements, and the delay of the phase of the second drive signal with respect to the first drive signal A controller that adjusts the magnitude of the output power by adjusting a certain first phase difference;
By using the second phase difference, which is the phase delay of the current flowing through the power feeding side coil with respect to the output voltage of the inverter circuit, the time during which the adjustment capacitor is charged in one cycle of the second drive signal and the adjustment The capacitor is made to function as an acquisition unit that acquires the first phase difference at which the time when the capacitor is discharged becomes equal to the power control start angle,
The program is characterized in that the control unit adjusts the magnitude of the output power by adjusting the first phase difference within a range equal to or less than the power control start angle. A plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points, the direct current applied to the pair of input points by switching of the plurality of conversion switch elements An inverter circuit that converts a voltage into an AC voltage and outputs the AC voltage from the pair of output points,
A power supply side coil that is electrically connected between the pair of output points and that supplies output power in a non-contact manner to the power receiving side coil by applying the AC voltage,
It is electrically connected between at least one of the pair of output points and the power supply side coil, has an adjusting capacitor and a plurality of adjusting switch elements, by switching of the plurality of adjusting switch elements, A power correction circuit for charging and discharging the adjustment capacitor, wherein the inverter circuit is a method of controlling a contactless power supply device operating in a lag phase mode in which a current phase becomes a lag phase with respect to a voltage phase,
The first drive signal controls the plurality of conversion switch elements, the second drive signal controls the plurality of adjustment switch elements, and the delay of the phase of the second drive signal with respect to the first drive signal A control process for adjusting the magnitude of the output power by adjusting a certain first phase difference;
By using the second phase difference, which is the phase delay of the current flowing through the power feeding side coil with respect to the output voltage of the inverter circuit, the time during which the adjustment capacitor is charged in one cycle of the second drive signal and the adjustment An acquisition process for acquiring, as a power control start angle, a first phase difference that makes the time at which the capacitor is discharged equal,
The control process adjusts the magnitude of the output power by adjusting the first phase difference within a range equal to or less than the power control start angle.

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