JP2017216783A - Non-contact power supply device, non-contact power transmission system, program, and control method for non-contact power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power supply device, a non-contact power transmission system, a program, and a control method for the non-contact power supply device that even when a relative positional relation between a power supply side coil and a power reception side coil varies, easily secure required power in a short period of time.SOLUTION: A non-contact power supply device 2 includes a control circuit 23 configured to adjust the magnitude of output power by adjusting a drive phase difference θ, a phase delay of second drive signals G6, G7 (G5, G8) with respect to first drive signals G1, G4 (G2, G3). Using a voltage current phase difference φ, the control circuit 23 acquires, as a power control start angle, a drive phase difference θ that equalizes a time in which an adjustment capacitor C1 is charged with a time in which the adjustment capacitor C1 is discharged in a single period of the second drive signals. The control circuit 23 adjusts the magnitude of the output power by adjusting the drive phase difference θ within a range equal to or smaller than the power control start angle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-contact power supply device, a non-contact power transmission system, a program, and a control method for the non-contact power supply device, and more specifically, a non-contact power supply device that performs non-contact power supply to a load, a non-contact power transmission system, The present invention relates to a program and a control method for a non-contact power supply apparatus.

  2. Description of the Related Art Conventionally, a non-contact power feeding apparatus that supplies power to a load in a non-contact manner using electromagnetic induction has been proposed (see, for example, Patent Document 1).

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

JP2013-243929A

  By the way, in the non-contact power feeding device as described above, depending on the relative positional relationship between 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 (moving body). The coupling coefficient between the primary side coil and the secondary side 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 non-contact power feeding device may decrease, and the output power may be insufficient for the required power. is there.

  The present invention has been made in view of the above-described reasons. Even when the relative positional relationship between the power feeding side coil and the power receiving side coil is changed, the non-contact power feeding device and the non-contact power which can easily secure necessary power in a short time. It is an object to provide a transmission system, a program, and a control method for a non-contact power supply apparatus.

  A non-contact power feeding device according to one embodiment of the present invention includes an inverter circuit, a power feeding coil, a power correction circuit, and a control circuit. The inverter circuit includes a plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points. The inverter circuit converts a DC voltage applied to the pair of input points into an AC voltage and outputs the AC voltage from the pair of output points by switching of the plurality of conversion switch elements. The power supply side coil is electrically connected between the pair of output points, and supplies the output power in a non-contact manner to the power reception side coil when the AC voltage is applied. The power correction circuit is electrically connected between at least one of the pair of output points and the power feeding side coil, and includes 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 slow phase 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 obtain 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 less than the power control start angle. The second phase difference is a phase delay of a current flowing in the power supply side coil with respect to an output voltage of the inverter circuit.

  Moreover, the non-contact electric power transmission system which concerns on 1 aspect of this invention is equipped with the said non-contact electric power feeder and the non-contact electric power receiving apparatus which has the said receiving side coil. The contactless power receiving device is configured such that the output power is supplied to the power receiving side coil in a contactless manner from the contactless power feeding device.

  A program according to one embodiment of the present invention causes a computer used for a non-contact power supply device to function as a control unit and an acquisition unit. The non-contact power feeding device includes an inverter circuit, a power feeding side coil, and a power correction circuit. The inverter circuit includes a plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points. The inverter circuit converts a DC voltage applied to the pair of input points into an AC voltage and outputs the AC voltage from the pair of output points by switching of the plurality of conversion switch elements. The power supply side coil is electrically connected between the pair of output points, and supplies the output power in a non-contact manner to the power reception side coil when the AC voltage is applied. The power correction circuit is electrically connected between at least one of the pair of output points and the power feeding side coil, and includes 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 slow phase 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 that 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 obtain 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 phase delay of a current flowing in the power supply side coil with respect to an output voltage of the inverter circuit.

  A control method for a non-contact power feeding device according to one embodiment of the present invention includes a control process and an acquisition process. The non-contact power feeding device includes an inverter circuit, a power feeding side coil, and a power correction circuit. The inverter circuit includes a plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points. The inverter circuit converts a DC voltage applied to the pair of input points into an AC voltage and outputs the AC voltage from the pair of output points by switching of the plurality of conversion switch elements. The power supply side coil is electrically connected between the pair of output points, and supplies the output power in a non-contact manner to the power reception side coil when the AC voltage is applied. The power correction circuit is electrically connected between at least one of the pair of output points and the power feeding side coil, and includes 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 slow phase mode in which the current phase is delayed with respect to the voltage phase. In the control process, the plurality of conversion switch elements are controlled by a first drive signal, and the plurality of adjustment switch elements are controlled by 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 a second phase difference that is a phase delay of the current flowing in the power supply coil with respect to the output voltage of the inverter circuit. A first phase difference at which the time and the time for discharging the adjustment capacitor are equal is obtained 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 less than the power control start angle. The second phase difference is a phase delay of a current flowing in the power supply side coil with respect to an 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 necessary power in a short time.

FIG. 1 is a circuit diagram showing a non-contact power transmission system according to an embodiment of the present invention. FIG. 2 is a waveform diagram showing a first drive signal and a second drive signal of the non-contact power feeding apparatus according to one embodiment of the present invention. FIG. 3 is a graph showing an example of resonance characteristics in the above-described non-contact power feeding apparatus. FIG. 4A and FIG. 4B are graphs showing examples of resonance characteristics in the above-described non-contact power feeding apparatus. FIG. 5 is a graph showing an example of the phase difference characteristic in the case of the initial slow phase in the above non-contact power feeding apparatus. FIG. 6A is an explanatory diagram showing a first charging mode of the power correction circuit in the above-described non-contact power feeding apparatus. FIG. 6B is an explanatory diagram showing a first discharge mode of the power correction circuit in the above-described contactless power supply device. FIG. 6C is an explanatory diagram illustrating a second charging mode of the power correction circuit in the above-described contactless power supply device. FIG. 6D is an explanatory diagram illustrating a second discharge mode of the power correction circuit in the non-contact power supply apparatus according to the embodiment. 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 is 90 degrees in the non-contact power feeding apparatus same as above. 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 is 45 degrees in the contactless power supply apparatus same as above. FIG. 9 is a flowchart showing output power control in the above-described contactless power supply apparatus.

(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) included in the non-contact power feeding device and the secondary side coil (power receiving side coil) included in 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 side coil to the secondary side coil. As a result, the non-contact power supply device supplies power to the load. This type of non-contact power feeding apparatus constitutes a non-contact power transmission system together with a non-contact power receiving apparatus provided in a load.

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

  The non-contact power transmission system 1 of the present embodiment includes a non-contact power feeding device 2 having a primary side coil L1 and a non-contact power receiving device 3 having a secondary side coil L2. The non-contact power receiving device 3 is configured so that output power is supplied from the non-contact power feeding device 2 in a non-contact manner. Here, the output power is power output from the non-contact power feeding device 2 and is supplied from the primary coil L1 to the secondary coil L2 in a non-contact 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 a conducting wire is wound spirally on a plane.

  In the present 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 includes a storage battery 4 and travels using 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. In addition, although the electric vehicle which drive | works with the driving force which arises with an electric motor is demonstrated as an example of an electric vehicle here, an electric vehicle is not restricted to an electric vehicle, For example, a two-wheeled vehicle (electric motorcycle), an electric bicycle, etc. may be sufficient.

  The non-contact power feeding device 2 charges the storage battery 4 of the electric vehicle by supplying the non-contact power receiving device 3 with power supplied from a commercial power source (system power source) or a power generation facility such as a solar power generation facility. 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 source 5 and contactless. A case where DC power is supplied to the power supply device 2 will be described as an example. Note that, 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 alternating current into direct current.

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

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

  Thereby, 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 at the secondary coil L2. The DC voltage is obtained by rectifying by the circuit 31 and further smoothing by the smoothing capacitor C2. 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 non-contact power feeding device 2 includes a power correction circuit 22 that forms a resonance circuit (hereinafter referred to as “primary side resonance circuit”) together with the primary side coil L1, and a pair of primary side capacitors C11, C12 is provided. In the non-contact power receiving device 3, the secondary coil L2 forms a resonance circuit (hereinafter referred to as “secondary resonance circuit”) together with the pair of secondary capacitors C21 and C22. And the non-contact electric power transmission system 1 of this embodiment employs a magnetic field resonance method (magnetic resonance method) in which electric power is transmitted by resonating the primary side resonance circuit and the secondary side resonance circuit. That is, the non-contact power transmission system 1 is configured so that the primary side coil L1 and the secondary side coil L2 are not separated even when the primary side coil L1 and the secondary side coil L2 are relatively separated by matching the resonance frequencies of the primary side resonance circuit and the secondary side resonance circuit. The output power of the contact power supply device 2 can be transmitted with high efficiency.

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

  The contactless power supply 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 side coil L1.

  The inverter circuit 21 includes a plurality (four in this case) of conversion switch elements Q1 to Q4 that are 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 a DC voltage applied to the pair of input points 211 and 212 to an AC voltage by switching of 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 side coil L1 is electrically connected between a pair of output points 213 and 214, and supplies output power to the secondary side coil L2 in a non-contact manner by applying an AC voltage.

  The power correction circuit 22 is electrically connected between the output point 213 and the primary coil L1, and includes an adjustment capacitor C1 and a plurality (four in this case) of adjustment switch elements Q5 to Q8. The power correction circuit 22 adjusts the charging time and discharging time of the adjusting capacitor C1 by switching the plurality of adjusting switch elements Q5 to Q8. The power correction circuit 22 adjusts the charging time and discharging time of the adjustment capacitor C1 to thereby adjust the phase difference of the current flowing in the primary coil L1 with respect to the output voltage of the inverter circuit 21 (the voltage-current phase difference, hereinafter , VI phase difference) 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 adjustment capacitor C1 is sufficiently larger than the capacity 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 frequency of the conversion switch elements Q1 to Q4 by adjusting the frequency of the first drive signal.

  In addition, the control circuit 23 performs phase difference control by adjusting the drive phase difference θ, which is a 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) a power control start angle according to the VI phase difference φ of the inverter circuit 21 when the inverter circuit 21 when the power correction circuit 22 is disabled is in the slow phase mode. Here, the power control start angle is a drive phase difference θ in which the time during which the adjustment capacitor C1 is charged and the time during which the adjustment capacitor C1 is discharged in one cycle of the second drive signal is equal. In other words, the power control start angle is the charge accumulated in the adjustment capacitor C1 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 enters the slow phase mode. The starting angle. The power control start angle is a value within a predetermined specified range. The “slow phase mode” is a mode in which the current phase is delayed (slow) with respect to the voltage phase. The driving 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 (lower limit value of the predetermined range) smaller than the power control start angle, that is, below the power control start angle, thereby increasing the output power. Adjust the height.

  Note that the “input point” and “output point” in this embodiment do not have to be an entity as a component (terminal) for connecting an electric wire or the like, for example, included in a lead of an electronic component or a circuit board. It may be a part of the conductor.

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

  The contactless power supply device 2 of the present embodiment includes a pair of input terminals T11 and T12. A DC power source 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 connected in a full bridge. That is, the inverter circuit 21 has a first arm and a second arm that are electrically connected in parallel between a pair of input points 211 and 212, and the first arm and the second arm have four conversion switches. It consists of elements Q1 to Q4. The first arm is composed of a series circuit of a (first) conversion switch element Q1 and a (second) conversion switch element Q2, and the second arm is a (third) conversion switch element Q3 (fourth). A) a series circuit with a conversion switch element Q4. The midpoint of the first arm (the connection point of the conversion switch elements Q1 and Q2) and the midpoint of the second arm (the connection point of the conversion switch elements Q3 and Q4) are a pair of output points 213 and 214. In the present embodiment, the four conversion switch elements Q1 to Q4 are n-channel depletion type MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

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

  Between the drains and sources of the four conversion switch elements Q1 to Q4, four diodes D1 to D4 are electrically connected to correspond to the four conversion switch elements Q1 to Q4 on a one-to-one basis. . Each of the diodes D1 to D4 is connected in a direction in which the drain side of each of the conversion switch elements Q1 to Q4 is a cathode. Here, the diodes D1 to D4 are parasitic diodes of the conversion switch elements Q1 to Q4.

  The power correction circuit 22 includes an adjustment capacitor C1 and four adjustment switch elements Q5 to Q8. The power correction circuit 22 includes 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 include four arms. It is composed of adjustment switch elements Q5 to Q8. The third arm is composed of a series circuit of a (first) adjustment switch element Q5 and a (third) adjustment switch element Q7, and the fourth arm is a (second) adjustment switch element Q6 (fourth). A) a series circuit with an adjustment switch element Q8. An adjustment capacitor C1 is electrically connected between the midpoint of the third arm (connection point of the adjustment switch elements Q5 and Q7) and the midpoint of the fourth arm (connection point of the adjustment switch elements Q6 and Q8). Connected. In this 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. Further, 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. . One end of the adjustment capacitor C1 is electrically connected to a connection point between the drain of the adjustment switch element Q5 and the drain of the adjustment switch element Q7. The other end of the adjustment capacitor C1 is electrically connected to a connection point between the source of the adjustment switch element Q6 and the source of the adjustment switch element Q8.

  Between the respective drains and sources of the four adjustment switch elements Q5 to Q8, four diodes D5 to D8 are electrically connected to correspond to the four adjustment switch elements Q5 to Q8 on a one-to-one basis. . 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 a 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 (microcomputer) as a main configuration. The microcomputer realizes a function as a control circuit (control unit) 23 by executing a program recorded in a memory of the microcomputer by a CPU (Central Processing Unit). The program may be recorded in advance in a memory of a microcomputer, may be provided by being recorded on a recording medium such as a memory card, or may be provided through an electric communication line. In the present embodiment, the control circuit 23 includes 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 non-contact power feeding apparatus 2 to function as the acquisition unit 231 and the control unit 232.

  The control unit 232 outputs 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 one to one with the four conversion switch elements Q1 to Q4. 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. .

  Further, the control unit 232 outputs second drive signals G5 to G8 for switching on and off 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 applies the first drive signal 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. Although G5 to G8 are directly output, this is not restrictive. For example, the non-contact power feeding apparatus 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 converts the switch element. Q1 to Q4 and adjustment switch elements Q5 to Q8 may be driven.

  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 side 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 side 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. Between the primary side coil L1 and the 2nd primary side capacitor | condenser C12, the current sensor 25 which consists of a current transformer, for example is provided. 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 measured value. The measurement unit 24 is configured to output the measurement value to the control circuit 23. The control circuit 23 monitors the magnitude of the output power output from the primary side coil L1 and the phase of the current flowing through the primary side coil L1, using the measurement values measured by the measurement unit 24.

<Basic operation>
Next, the basic operation of the non-contact power feeding device 2 of the present embodiment will be described with reference to FIGS. 1 and 2. In FIG. 2, with the horizontal axis as a time axis, 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 indicate ON / OFF of the corresponding switch element (conversion switch element, adjustment switch element).

(1) No power correction circuit Here, first, when there is no power correction circuit 22, only the primary coil L1 and the pair of primary capacitors C11 and C12 are electrically connected between the pair of output points 213 and 214. The operation of the non-contact power feeding device 2 will be described. The operation of the non-contact power feeding device 2 at this time is performed when the power correction circuit 22 stops operating in the circuit configuration of FIG. 1, 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 non-contact power feeding device 2 when it is fixed. Further, the case where the power correction circuit 22 has stopped operating can be said to be a case where the power correction circuit 22 is disabled.

  As shown in FIG. 2, the control unit 232 of the control circuit 23 includes first drive signals G1 and G4 corresponding to the conversion switch elements Q1 and Q4, and a first drive signal G2 corresponding to the conversion switch elements Q2 and Q3. , G3 generate signals having opposite phases (180 ° phase difference). Thereby, in the inverter circuit 21, the pair of the first conversion switch element Q1 and the fourth conversion switch element Q4, the 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 to an AC voltage and outputs the AC voltage from the pair of output points 213 and 214 by switching of the plurality of conversion switch elements Q1 to Q4. . Hereinafter, with respect to the output voltage of the inverter circuit 21, the voltage at which the first output point 213 of the pair of output points 213 and 214 has a high potential is referred to as “positive polarity”, and the second output point 214 has a high potential. This voltage is called “negative polarity”. That is, the output voltage of the inverter circuit 21 is positive when the conversion switch elements Q1 and Q4 are on, and is negative when the conversion switch elements Q2 and Q3 are on.

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

  By the way, when there is no power correction circuit 22, in the non-contact electric power feeder 2 of this embodiment, the primary side coil L1 comprises a primary side resonance circuit with a pair of primary side 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 frequency of the first drive signals Q1 to Q4), and the operating frequency of the inverter circuit 21 is the primary side. A peak is reached when it matches the resonant frequency of the resonant circuit.

  Here, when 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 a change in the resonance characteristics of the non-contact power feeding device 2 when the relative positional relationship between the primary side coil L1 and the secondary side coil L2 changes. In FIG. 3, the horizontal axis represents the frequency (operating frequency of the inverter circuit 21), and the vertical axis represents the output power of the non-contact power feeding device 2. The relative positional relationship between the primary coil L1 and the secondary coil L2 is as follows. The resonance characteristics of the non-contact power feeding device 2 in different cases are indicated 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 laws such as the Radio Law. In this case, a frequency that is less than the lower limit value fmin and exceeds 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 indicated by “X1” in FIG. 3, for example, the output of the non-contact power feeding device 2 can be adjusted no matter how the operating frequency of the inverter circuit 21 is adjusted. There is a possibility that electric power does not have the required size (hereinafter referred to as “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 non-contact power feeding device 2 does not reach the peak, and as a result, the target value The output power may be insufficient with respect to P1. 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 non-contact power feeding 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 examples of FIGS. 4A and 4B, the power in the hatched portion (shaded area) is insufficient with respect to the target value P1.

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

(2) With power correction circuit Next, when there is a power correction circuit 22 as shown in FIG. 1, that is, between the pair of output points 213 and 214, the primary coil L1, the pair of primary capacitors C11 and C12, and The operation of the non-contact power feeding 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 second drive signals G6 and G7 corresponding to the adjustment switch elements Q6 and Q7, and a second drive signal G5 corresponding to the adjustment switch elements Q5 and Q8. , G8 generate signals having mutually opposite phases (phase difference of 180 degrees). Thus, in the power correction circuit 22, a pair of the second adjustment switch element Q6 and the third adjustment switch element Q7, and a pair of the first adjustment switch element Q5 and the fourth adjustment 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 performing phase control.

  In the contactless power supply device 2 of the present embodiment, the power correction circuit 22 can adjust the VI phase difference φ of the inverter circuit 21 by adjusting the charging time and discharging time of the adjustment capacitor C1. As a result, when the output power of the non-contact power feeding 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.

  In the present embodiment, as described above, the first drive signals G1, G4 corresponding to the conversion switch elements Q1, Q4 and the first drive signals G2, G3 corresponding to the conversion switch elements Q2, Q3 are as follows. The signals are opposite in phase (phase difference 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 are opposite in phase (phase difference 180 degrees). Signal.

  Here, the drive phase difference θ between the first drive signal and the second drive signal in the present embodiment is the phase delay 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 the phase delay of the second drive signals G5 and G8 with respect to G2 and G3 (see FIG. 2). That is, there is a 180 degree difference 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 driving phase difference θ differs depending on which phase delay is the driving phase difference θ. Therefore, in this 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 determined as the drive position. It is defined as a phase difference θ. As described above, the drive phase difference θ corresponds to the first phase difference.

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

(1) Without power correction circuit Here, first, similarly to the above-mentioned “basic operation” column, when there is no power correction circuit 22, that is, between the pair of output points 213 and 214, the primary coil L1 and the pair of primary sides. 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 slow phase mode according to the relationship between the operating frequency of the inverter circuit 21 and the resonant frequency of the primary side resonant circuit, for example.

  The slow phase mode is a mode in which the inverter circuit 21 operates in a state where 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 with respect to the voltage phase. In the slow phase mode, the switching operation of the inverter circuit 21 is soft switching. Therefore, in the slow phase mode, the switching loss of the conversion switch elements Q1 to Q4 can be reduced, and stress is not easily applied to the conversion switch 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 is ahead of 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 easily applied to the conversion switch elements Q1 to Q4. Therefore, it is preferable that the inverter circuit 21 operates in the slow phase mode rather than the fast phase mode. In the present embodiment, the inverter circuit 21 is controlled to operate in the slow phase mode. At this time, the VI phase difference φ is a value within the range of 0 to 90 degrees. 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 coil L1, the pair of primary capacitors C11 and C12, and the power correction circuit 22 are electrically connected. Will be described.

  Similar to the inverter circuit 21, the power correction circuit 22 can operate in any one of the fast-phase mode and the slow-phase mode. However, it is preferable that the power correction circuit 22 also operates in the slow phase mode instead of the fast phase mode. Therefore, in the present embodiment, the power correction circuit 22 is configured to operate in the slow phase mode, similarly to the inverter circuit 21.

  FIG. 5 shows characteristics (phase difference characteristics) with respect to the drive phase difference θ of the output power of the non-contact power feeding device 2 when the inverter circuit 21 is in the slow phase 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 feeding device 2.

  On the other hand, when the inverter circuit 21 is in the slow phase mode (hereinafter referred to as “initial slow phase”) without the power correction circuit 22, the output power of the non-contact power feeding device 2 is, for example, as shown in FIG. It changes according to the drive phase difference θ. In the example of FIG. 5, the output power of the non-contact power feeding device 2 is maximized and maximized when the drive phase difference θ is 270 degrees, and minimized and minimized when the drive phase difference θ is 180 degrees. It varies depending on the phase difference θ. In the case of the initial delay phase, both the inverter circuit 21 and the power correction circuit 22 operate in the delay phase 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, the first section Z1 and the 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 when 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 “output power control” for adjusting the magnitude of output power in the non-contact power feeding 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. The magnitude of the output power is adjusted 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 the output power by adjusting the frequency 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 frequency of the first drive signals G1 to G4. That is, as described in the column “(1) No power correction circuit” in “Basic operation” above, the magnitude of the output power output from the primary coil L1 is the operating frequency of the inverter circuit 21 (that is, the first It changes according to the frequency of the drive signals Q1 to Q4 (see FIG. 3). Therefore, in the frequency control, the control unit 232 of the control circuit 23 adjusts the operating frequency of the inverter circuit 21 and adjusts the magnitude of the output power by adjusting the frequency of the first drive signals G1 to G4. In other words, the control unit 232 can adjust the magnitude of the output power by controlling the VI phase difference φ in the frequency control. In this case, the power correction circuit 22 is in an invalid state (stopped 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 the frequency control is limited to the permitted frequency band F1.

  And when the magnitude | size of the output electric power adjusted by frequency control is less than a predetermined target value, the control circuit 23 performs phase difference control demonstrated below. That is, when the output power is insufficient with respect to the target value by frequency control alone, the control circuit 23 compensates for the shortage by phase difference control.

  First, the control circuit 23 starts the power correction circuit 22 by setting the drive phase difference θ once to 360 degrees.

  The acquisition unit 231 of the control circuit 23 acquires the drive phase difference θ, which is a value (angle) within a specified range, as the power control start angle according to the VI phase difference φ. The control unit 232 has 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) of the specified range. The magnitude of the output power is adjusted by adjusting the drive phase difference θ, which is a delay of.

  Here, the power control start angle corresponds to the drive phase difference θ at which charges start to be accumulated in the capacitor C1 when the drive phase difference θ is gradually reduced from 360 degrees. Therefore, 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 using Formula 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) using the acquired power control start angle as an initial value. Thus, the magnitude of the output power of the non-contact power feeding device 2 is adjusted. The power control start angle is an angle belonging to a 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 is not always necessary to set the lower limit value. For example, the predetermined value may be another value (for example, 271) in consideration of an output power error.

  As can be seen from FIG. 5, the output power of the non-contact power feeding device 2 changes according to the drive phase difference θ, so that the control unit 232 adjusts the drive phase difference θ to a set value, thereby increasing the magnitude of the output power. Adjustment is possible. Specifically, the control unit 232 gradually decreases the drive phase difference θ from the power control start angle to the lower limit value (270 degrees) of the specified range, with the power control start angle as an initial value. Thereby, as the control circuit 23 gradually changes (decreases) the set value within the specified range, the output power of the non-contact power feeding device 2 gradually increases.

  In the present embodiment, the frequency at the time of phase difference control is the same value as the frequency after adjustment by frequency control. In short, while performing 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, thereby increasing the output power of the non-contact power feeding device 2. The principle of adjusting the height will be described with reference to FIGS.

  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 non-contact 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 depends on the 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 side coil L1, it is also referred to as “primary side current I1” hereinafter. The direction of the primary current I1 flowing from the first output point 213 to the second output point 214 through the primary side capacitor C11, the power correction circuit 22, the primary side coil L1, and the primary side capacitor C12, that is, in FIG. The direction of the primary current I1 indicated by the arrow is referred to as “positive direction”. The direction of the primary current I1 flowing from the second output point 214 to the first output point 213 through the primary side capacitor C12, the primary side coil L1, the power correction circuit 22, and the primary side capacitor C11, that is, in FIG. The direction opposite to the primary 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 current I1. In FIGS. 6A to 6D, thick arrows indicate current paths, and adjustment switch elements with dotted circles indicate elements in an on state.

  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 flows (hereinafter referred to as “the power correction circuit 22”). "First charging 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 primary current I1 in the positive direction flows (hereinafter referred to as “the power correction circuit 22”). "First discharge mode"). FIG. 6C shows the state of the power correction circuit 22 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 flows (hereinafter referred to as “the power correction circuit 22”). "Second charging mode"). FIG. 6D shows the state of the power correction circuit 22 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 negative direction flows (hereinafter referred to as “the power correction circuit 22”). "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 charging mode period and the first discharging mode period are equal. When the drive phase difference θ is equal to the power control start angle, the time lengths of the second charging mode period and the second discharging mode period are equal. Therefore, in this case, no charge is accumulated in the capacitor C1.

  Next, with reference to FIGS. 7 and 8, the relationship between the drive phase difference θ and the balance between 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 current “I1”, and the two types of second drive signals “G6, G7” are shown in order from the top with the horizontal axis as the time axis. Represents. The two types of second drive signals here have different drive phase differences θ. Note that “ON” and “OFF” in FIGS. 7 and 8 indicate ON / OFF of the corresponding switch element (conversion switch element, adjustment switch element).

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

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

  As is clear from FIG. 7, if the power control start angle is 360 degrees, the time for charging the adjustment capacitor C1 and the time for discharging the adjustment capacitor C1 in one cycle of the second drive signal are as follows. Equal (equilibrium). Hereinafter, the time during which the adjustment capacitor C1 is charged in one cycle of the second drive signal is referred to as a 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 a discharge time. For example, if the drive phase difference θ is 360 degrees, the sum of “Tca1” and “Tca2” and the sum of “Tda1” and “Tda2” have the same length. Note 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 is that the difference in time length between the charging time and the discharging time is less than a predetermined value. It corresponds to the equilibrium state.

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

  As described above, when the drive phase difference θ is gradually changed so as to approach 270 degrees from 360 degrees, the balance between the charge time and the discharge time is broken in one cycle of the second drive signal, and the charge time is gradually occupied. The proportion increases. In FIG. 7, for convenience of description, the description of the change 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 the initial value along with the change in the drive phase difference θ. It changes from (90 degrees here). That is, when the charging time exceeds the discharging time, a current flows into the adjustment capacitor C1, and the phase of this current advances by 90 degrees with respect to the phase of the voltage across the adjustment capacitor C1. That is, the adjustment capacitor C1 functions as a phase advance capacitor. And VI phase difference (phi) becomes small with the electric current which flows in the capacitor | condenser C1 for adjustment, and output electric power increases. That is, when the drive phase difference θ is made 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 current of the adjustment capacitor C1 is set to 90 degrees). To act to maintain). As a result, as the drive phase difference θ approaches 270 degrees from the power control start angle, the output power of the non-contact power feeding device 2 gradually increases.

  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, the charge time and the discharge time are balanced even in a region where the drive phase difference θ is equal to or less than the power control start angle. For example, if the relationship that 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 infinitely. However, in practice, when the VI phase difference φ decreases, the charging time and the discharging time are balanced again, and the voltage of the adjustment capacitor C1 does not diverge.

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

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

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

  From the above, not only when the VI phase difference φ is 90 degrees, but in the case of “initial delay phase”, if the drive phase difference θ changes so as to approach 270 degrees from the power start angle, 1 of the second drive signal 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 is reduced, and the charging time and the discharging time are balanced again.

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

  That is, in the case of “initial delay phase”, there is a power control start point within a specified range (for example, 270 degrees to 360 degrees) even though 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 non-contact power feeding device 2 gradually increases. However, since the output power of the non-contact power feeding 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 does not output during this period. The magnitude of power cannot be adjusted.

  Therefore, in the present embodiment, the acquisition unit 231 acquires (calculates) the drive phase difference θ at which the voltage across the adjustment capacitor C1 starts to increase as the power control start angle using the above formula 2. The control unit 232 adjusts the magnitude of the output power by gradually changing the acquired power control start point as an initial value from the power control start point to the lower limit value of the specified range. Thereby, the control part 232 can adjust the magnitude | size of output electric power more quickly than the case where it changes gradually from the upper limit of a prescription | regulation range (270 degree | times-360 degree | times).

(3) Flow of Output Power Control Hereinafter, the flow of “output power control” of the present embodiment will be described with reference to the flowchart of FIG. Here, phase difference control processing among frequency control and phase difference control performed by the control circuit 23 will be described.

  When the control circuit 23 starts the power correction circuit 22 with the drive phase difference θ set to 360 degrees, 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 acquired power control start angle as an initial value to the drive phase difference θ (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 (“rated” in step S4), the drive phase difference θ is fixed to the value at that time (step S5). The control circuit 23 ends the process after executing Step S5. Thereby, the electric power output from the primary side coil L1 becomes equivalent to a 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 equal to or greater than the lower limit (“No” in step S6), the control circuit 23 decrements the drive phase difference θ (θ−1) (step S7), and returns to the process of step S4. By repeating these processes (steps S6 and S7), the control circuit 23 can gradually decrease 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 closer to the 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 an error has occurred (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 or not 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 decrease the output power, that is, approach a 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 is 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 (process for adjusting the magnitude of the output power). That is, the output power changes in a 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 an error has occurred. To do. Thereby, 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 value of the specified range). At this time, the control circuit 23 stops 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 supply device 2 according to the present embodiment soft-starts the inverter circuit 21 as described below at the start-up time when the inverter circuit 21 starts to operate.

  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 increasing, the soft start of the inverter circuit 21 is realized. Thereby, the sudden change of the voltage and electric current input into the non-contact electric power feeder 2 is suppressed, and the stress added to a circuit element can be reduced. Hereinafter, the process in which the control circuit 23 soft-starts the inverter circuit 21 by changing the duty ratios of the first drive signals G1 to G4 as described above is referred to as “start-up process”.

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

  When the startup 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 a 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 non-contact power feeding device 2 is in a state equivalent to “(2) With power correction circuit” (see the column “Basic operation” above). At this time, it is preferable that the control circuit 23 once sets the drive phase difference θ to 360 (degrees) and starts the power correction circuit 22. Thereafter, the control circuit 23 uses 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 the 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 increased. Degradation can be avoided.

  Incidentally, the control circuit 23 may be configured to start the operation of the power correction circuit 22 and adjust the output power by phase difference control before adjusting the output power by 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) in which the output power control as described above is performed. Has a search mode. The control circuit 23 executes a process in the search mode before performing the startup process, the frequency control, and the phase difference control, that is, before operating in the normal mode, so that the control circuit 23 is connected between the primary side coil L1 and the secondary side coil L2. Estimate the coupling coefficient.

  From the coupling coefficient, the control circuit 23 determines the resonance characteristics (that is, the operating frequency of the inverter circuit 21 and the output of the non-contact power feeding device 2) as described in the column “(1) With power correction circuit” of “Basic operation”. The relationship with power) 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 slow phase mode (that is, does not enter the fast phase mode), for example, for the operating frequency f1 of the inverter circuit 21. Thereby, 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 slow phase 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 slow phase 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 conducting wire is spirally wound around the core.

  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.

  Further, the load to which output power is supplied contactlessly (that is, supplied with power) from the contactless power supply device 2 is not limited to an 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. There may be no electrical equipment such as lighting fixtures.

  Further, the transmission method of the output power from the non-contact power supply device 2 to the non-contact power reception 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 switch elements Q1 to Q4 and each of the adjustment switch elements Q5 to Q8 may be composed of 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, and 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 measurement unit 24 only needs to measure the magnitude of the current flowing through the primary coil L1, the current sensor 25 is not limited to between the primary coil L1 and the second primary capacitor C12, but the primary coil L1. On the path of the current flowing through

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

  In addition, it is not essential that the acquisition unit 231 and the control unit 232 are provided in one control circuit 23. 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 that can convert a DC voltage into an AC voltage and output it, and is not limited to a full-bridge inverter circuit in which four conversion switch elements Q1 to Q4 are connected in a full bridge. The inverter circuit 21 may be a half-bridge inverter circuit, for example.

  In the non-contact power feeding device 2, the power correction circuit 22 only needs to 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. May be electrically connected between the output point 214 and the primary coil L1.

  In the non-contact power feeding apparatus 2, the power correction circuit 22 is disabled when performing frequency control. However, even when the drive phase difference θ is set to 360 degrees as an initial value, the power correction circuit 22 is operated. Good. At this time, the first drive signals G1 and G4 and the second drive signals G6 and G7 change similarly in synchronism, and the first drive signals G2 and G3 and the second drive signals G5 and G8 synchronize similarly. Change. For this reason, even if the power correction circuit 22 operates, no charge is accumulated in the adjustment capacitor C1.

<Summary>
As described above, the contactless power supply device 2 according to the first aspect of the present invention includes the inverter circuit 21, the power supply side coil L <b> 1, the power correction circuit 22, and the control circuit 23. The inverter circuit 21 includes a plurality of conversion switch elements Q1 to Q4 that are 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 a DC voltage applied to the pair of input points 211 and 212 to an AC voltage by switching of 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 non-contact 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 supply side coil L1, and includes an adjustment capacitor C1 and a plurality of adjustment switch elements Q5 to Q8. Yes. 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 slow phase mode in which the current phase is delayed with respect to the voltage phase. The control circuit 23 adjusts the first phase difference (drive phase difference θ), 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). Thus, the magnitude of the output power is adjusted. The control circuit 23 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 the adjustment capacitor C1. The first phase difference that is equal to the discharge time 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 below the power control start angle. The second phase difference is a phase delay of the current flowing in the power supply side coil L1 with respect to the output voltage of the inverter circuit 21.

  According to this configuration, the non-contact power feeding device 2 adjusts a phase difference that is a phase delay of the second drive signals G6, G7 (G5, G8) with respect to the first drive signals G1, G4 (G2, G3). The magnitude of the output power can be adjusted. Therefore, even 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 makes it easy to secure necessary power by adjusting the phase difference. Moreover, the non-contact power feeding device 2 acquires a power control start angle that is an angle at which charges start to accumulate in the adjustment capacitor C1 using the second phase difference. The non-contact power feeding 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, so that necessary power can be easily secured in a short time.

  In the non-contact power feeding 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, gradually decreases the first phase difference, and outputs Increase power. According to this configuration, the output power can be increased by gradually reducing the first phase difference.

  In the contactless power supply device 2 according to the third aspect of the present invention, in the first or second aspect, the control circuit 23 adds the second phase difference to a predetermined value to obtain the power control start angle. . According to this configuration, the contactless power supply device 2 can acquire the power control start angle by adding a predetermined value to the second phase difference (VI phase difference φ).

  In the contactless power supply device 2 according to the fourth aspect of 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 the range in which the magnitude of the output power is adjusted from the specified range (270 degrees to 360 degrees).

  In the contactless power supply device 2 according to the fifth aspect of the present invention, in any one of the first to fourth aspects, the control circuit 23 may adjust the adjustment capacitor when the magnitude of the output power is reduced. When the voltage of C1 becomes 0, the power correction circuit 22 is stopped. When the magnitude of the output power is decreasing, the non-contact power feeding device 2 gradually increases the discharge period of the adjustment capacitor C1 by adjusting the drive phase difference θ. 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. And the non-contact electric power feeder 2 can abbreviate | omit control in the area where output power does not change by suppressing adjustment of the magnitude | size of output power by the electric power correction circuit 22. FIG.

  In the non-contact power feeding device 2 according to the sixth aspect of 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 coil. L1 is electrically connected. According to this configuration, the non-contact power feeding device 2 adjusts a phase difference that is a phase delay of the second drive signals G6, G7 (G5, G8) with respect to the first drive signals G1, G4 (G2, G3). The magnitude of the output power can be adjusted.

  Moreover, the non-contact power transmission system 1 according to the seventh aspect of the present invention includes the non-contact power feeding device 2 according to any one of the first to sixth aspects and the non-contact power receiving device 3 having the power 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. According to this configuration, in the non-contact power transmission system 1, the non-contact power feeding device 2 can easily secure 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 for the non-contact power feeding device 2 to function as the control unit 232 and the acquisition unit 231. The non-contact power feeding device 2 includes an inverter circuit 21, a power feeding side coil L 1, and a power correction circuit 22. The inverter circuit 21 includes a plurality of conversion switch elements Q1 to Q4 that are 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 a DC voltage applied to the pair of input points 211 and 212 to an AC voltage by switching of 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 non-contact 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 supply side coil L1, and includes 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 a slow phase mode in which the current phase is delayed with respect to the voltage phase. The control unit 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 control unit 232 adjusts the first phase difference (drive phase difference θ) that is the phase delay of the second drive signals G6, G7 (G5, G8) with respect to the first drive signals G1, G4 (G2, G3). To adjust the magnitude of the 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 that is equal to the discharge time is acquired as the power control start angle. A control part adjusts the magnitude | size of output electric power by adjusting a 1st phase difference in the range below a power control start angle. The second phase difference is a phase delay of the current flowing in the power supply 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 non-contact 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 necessary power can be easily secured in a short time.

  A control method for a non-contact power supply apparatus according to a ninth aspect of the present invention includes a control process and an acquisition process. The non-contact power feeding device 2 includes an inverter circuit 21, a power feeding side coil L 1, and a power correction circuit 22. The inverter circuit 21 includes a plurality of conversion switch elements Q1 to Q4 that are 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 a DC voltage applied to the pair of input points 211 and 212 to an AC voltage by switching of 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 non-contact 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 supply side coil L1, and includes 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 a slow phase mode in which the current phase is delayed with respect to the voltage phase. In the control process, the plurality of conversion switch elements Q1 to Q4 are controlled by the first drive signals G1 to G4, and the plurality of adjustment switch elements Q5 to Q8 are controlled by the second drive signals G5 to G8. The control process is performed by adjusting the first phase difference (drive phase difference θ), 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). Adjust the magnitude of output power. The acquisition process uses the second phase difference (VI phase difference φ) to discharge the adjustment capacitor C1 and the time during which the adjustment capacitor C1 is charged in one cycle of the second drive signals G6, G7 (G5, G8). The first phase difference that is equal to the measured time 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 less than the power control start angle. The second phase difference is a phase delay of the current flowing in the power supply side coil L1 with respect to the output voltage of the inverter circuit 21.

  According to this control method, a function equivalent to that of the non-contact power feeding device 2 of the present embodiment can be realized without using the dedicated control circuit 23.

1 contactless power transmission system 2 contactless power feeding device 3 contactless power receiving device 21 inverter circuit 211, 212 pair of input points 213, 214 pair of output points 22 power correction circuit 23 control circuit 231 acquisition unit 232 control unit C1 adjustment capacitor G1 to G4 first drive signal G5 to G8 second drive signal L1 primary side coil (feeding side coil)
L2 secondary coil (receiving coil)
Q1 to Q4 conversion switch element Q5 to Q8 adjustment switch element θ Driving 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, and a direct current applied to the pair of input points by switching of the plurality of conversion switch elements An inverter circuit that converts the voltage into an alternating voltage and outputs the voltage from the pair of output points;
A power feeding side coil that is electrically connected between the pair of output points and supplies the output power in a non-contact manner to the power receiving side coil by applying the AC voltage;
Electrically connected between at least one of the pair of output points and the power supply side coil, and having an adjustment capacitor and a plurality of adjustment switch elements, and by switching the plurality of adjustment 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 operates in a lagging mode in which the current phase is lagging 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 charges the adjustment capacitor in one cycle of the second drive signal using a second phase difference that is a phase delay of a current flowing in the power supply coil with respect to an output voltage of the inverter circuit. By obtaining a first phase difference in which time and time for discharging the adjustment capacitor are equal as a power control start angle, and adjusting the first phase difference in a range equal to or less than the power control start angle, the output A non-contact power feeding device that adjusts the magnitude of electric power. The non-contact power feeding device according to claim 1, wherein the control circuit gradually decreases the first phase difference and gradually increases the output power with the power control start angle as an initial value. . The control circuit includes:
The contactless power supply device according to claim 1, wherein a value obtained by adding the second phase difference to a predetermined value is acquired as the power control start angle. The non-contact power feeding apparatus according to claim 3, wherein the predetermined value is 270 degrees. The control circuit stops the power correction circuit when the voltage of the adjustment capacitor becomes 0 when the magnitude of the output power is reduced. A contactless power supply device according to claim 1. 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 supply side coil. Power supply device. The non-contact power feeding device according to any one of claims 1 to 6,
A non-contact power receiving device having the power receiving side coil,
The non-contact power receiving apparatus is configured such that the output power is supplied to the power-receiving side coil in a non-contact manner from the non-contact power feeding apparatus. A plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points, and a direct current applied to the pair of input points by switching of the plurality of conversion switch elements An inverter circuit that converts the voltage into an alternating voltage and outputs the voltage from the pair of output points;
A power feeding side coil that is electrically connected between the pair of output points and supplies the output power in a non-contact manner to the power receiving side coil by applying the AC voltage;
Electrically connected between at least one of the pair of output points and the power supply side coil, and having an adjustment capacitor and a plurality of adjustment switch elements, and by switching the plurality of adjustment switch elements, A power correction circuit that charges and discharges the adjustment capacitor, and the inverter circuit includes a computer used in a non-contact power feeding device that operates in a lag mode in which a current phase is a lag phase with respect to a voltage phase.
The plurality of conversion switch elements are controlled by a first drive signal, the plurality of adjustment switch elements are controlled by a second drive signal, and the phase of the second drive signal is delayed with respect to the first drive signal. A controller that adjusts the magnitude of the output power by adjusting a first phase difference;
Using the second phase difference, which is the phase delay of the current flowing in the power supply 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 Function as an acquisition unit that acquires the first phase difference that is equal to the time when the capacitor is discharged as the power control start angle;
The said control part adjusts the magnitude | size of the said output electric power by adjusting the said 1st phase difference in the range below the said electric power control start angle. The program characterized by the above-mentioned. A plurality of conversion switch elements electrically connected between a pair of input points and a pair of output points, and a direct current applied to the pair of input points by switching of the plurality of conversion switch elements An inverter circuit that converts the voltage into an alternating voltage and outputs the voltage from the pair of output points;
A power feeding side coil that is electrically connected between the pair of output points and supplies the output power in a non-contact manner to the power receiving side coil by applying the AC voltage;
Electrically connected between at least one of the pair of output points and the power supply side coil, and having an adjustment capacitor and a plurality of adjustment switch elements, and by switching the plurality of adjustment switch elements, A power correction circuit that charges and discharges the adjustment capacitor, and the inverter circuit is a control method for a non-contact power feeding device that operates in a lagging phase in which a current phase is delayed with respect to a voltage phase,
The plurality of conversion switch elements are controlled by a first drive signal, the plurality of adjustment switch elements are controlled by a second drive signal, and the phase of the second drive signal is delayed 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;
Using the second phase difference, which is the phase delay of the current flowing in the power supply 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 of acquiring a first phase difference that is equal to a time when the capacitor is discharged as a 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 less than the power control start angle.

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