JP2019047675A - Power supply system - Google Patents

Abstract

To supply electric power to a load from a primary side to a secondary side without exchanging feeding information between the primary side and the secondary side and without need for installing an inverter on the primary side.SOLUTION: A power supply system 10 is a system for supplying electric power from a primary side 12 to a secondary side 14 in a non-contact manner. On the primary side 12, there is provided a change-over switch 15 capable of changing over a circuit on the primary side 12 supplying electric power from the primary side 12 to the secondary side 14 in a non-contact manner, to a resonance circuit or non-resonance circuit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply system that supplies power from a primary side to a secondary side in a contactless manner.

  As a power supply system that supplies power from the primary side to the secondary side in a contactless manner, for example, there is a system that couples a primary side coil and a secondary side coil with a magnetic field. There are the following four types of circuit systems for such a power supply system.

  (1) An NN circuit system (N: Non-Resonant) in which both the primary side and the secondary side are non-resonant circuits. (2) NS circuit system (S: Series) in which the primary side is a non-resonant circuit and the secondary side is a resonant circuit in which a secondary coil and a resonant capacitor are connected in series. (3) An SN circuit system in which the primary side is a resonance circuit in which a primary coil and a resonance capacitor are connected in series, and the secondary side is a non-resonance circuit. (4) Magnetic field resonance coupling SS circuit in which the primary side is a resonance circuit in which a primary side coil and a resonance capacitor are connected in series, and the secondary side is a resonance circuit in which a secondary side coil and a resonance capacitor are connected in series. method.

  In Patent Document 1, the received power is detected by a secondary-side electric vehicle, and the power-receiving device is controlled by transmitting the secondary-side power-receiving status to the primary-side power-feeding device using a communication device. Is disclosed.

  According to Patent Document 2, since the communication method is required in the control method of Patent Document 1, not only the electric vehicle and the power supply device are expensive, but also the combination of the electric vehicle and the power supply device with the same communication method is required. The problem of being unable to charge is disclosed.

  In order to solve this problem, Patent Document 2 discloses a high-efficiency power without performing wireless communication between the primary side and the secondary side by a power supply device including a high-frequency driver, an arithmetic device, and a control device. It is disclosed to enable transmission. In this case, the high-frequency driver converts the power of the primary AC power source into high-frequency power that can be transmitted to the secondary mobile body by resonating (resonating) the magnetic field, and supplies it to the primary coil. The arithmetic unit estimates an equivalent circuit parameter of power transmission from the primary side coil to the secondary side coil by the resonance method based on the frequency of the high frequency driver, the transmission current, and the transmission voltage. The control device estimates the received power of the secondary coil from the estimated equivalent circuit parameters, and controls the high-frequency driver so that the estimated received power is maximized.

Japanese Patent No. 4453541 JP 2012-157127 A

  However, in Patent Document 2, contactless power transmission from the primary side to the secondary side is possible without using a communication device, while the voltage of the AC power source is converted to a desired frequency on the primary side. An inverter is required.

  Therefore, when charging by supplying power to a load such as a secondary battery arranged on the secondary side by non-contact power transmission from the primary side to the secondary side, a simpler configuration and control method, Specifically, it is desirable to charge the load by supplying power from the primary side to the secondary side without providing an inverter on the primary side.

  The present invention has been made in consideration of such problems, and without exchanging power supply information between a primary side which is a power supply side and a secondary side which is a power reception side, and 1 An object of the present invention is to provide a power supply system capable of supplying power from a primary side to a load on the secondary side without providing an inverter on the secondary side.

  The present invention relates to a power supply system that supplies power from the primary side to the secondary side in a contactless manner, the power supply system being provided on the primary side and contactless from the primary side to the secondary side. The primary side circuit for supplying electric power at the switching unit can be switched to a resonant circuit or a non-resonant circuit.

  Thus, a simple configuration is achieved without exchanging information such as power supply information between the primary side on the power supply side and the secondary side on the power reception side, and without using an inverter on the primary side. In addition, non-contact power supply from the primary side to the secondary side can be performed at low cost. That is, the primary side circuit that supplies power without contact is switched to the resonant circuit or the non-resonant circuit with a simple configuration using the switching means, thereby satisfying the power demand from the secondary side. Accordingly, the non-contact power supply can be appropriately performed.

  In addition, since the inverter is not used on the primary side, the frequency and voltage of the base power source such as an AC power source attached to the infrastructure on which the primary side is installed are used as they are, and the power supply target such as an electric vehicle is not used. Contact power feeding can be performed. Specifically, when power is supplied to the power supply object using general infrastructure, the frequency (commercial frequency) of the commercial power source can be used as it is. In addition, when power is supplied to a power supply target in a ship or an aircraft, the infrastructure frequency in the ship and the aircraft can be used as it is. For example, in the aircraft, a frequency of 400 Hz that is an infrastructure frequency in the aircraft can be used as it is.

  Here, the primary side includes a power source that supplies power to the resonant circuit or the non-resonant circuit, a primary side switch that electrically connects the power source and the resonant circuit or the non-resonant circuit after switching, Switching means and primary side control means for controlling switching by the switching means and on / off of the primary side switch. Thereby, it is possible to efficiently supply power from the power source to the resonant circuit or the non-resonant circuit.

  In this case, power is supplied from the power source to the non-resonant circuit in a state where the switching unit switches to the non-resonant circuit and the primary side switch connects the power source and the non-resonant circuit. Thus, non-contact power supply from the primary side to the secondary side is started. Thereby, at the start of the non-contact power supply, the non-contact power supply can be performed while avoiding a large current exceeding an allowable current value from flowing through the primary side and the secondary side.

  The non-resonant circuit and the resonant circuit include a primary side coil, and the secondary side includes a secondary side coil arranged with a gap from the primary side coil, and the secondary side coil. A non-contact power supply from the primary side to the secondary side is performed by magnetic field coupling between the primary side coil and the secondary side coil. Thereby, the non-contact power supply can be performed efficiently.

  The secondary side may have a resonance circuit including the secondary coil. Thereby, at the start of the non-contact power supply, power supply is started by an NS circuit method (hereinafter also referred to as an NS circuit), and then the secondary side (the load) is requested for power. Accordingly, it becomes possible to supply power by switching to the SS circuit system (hereinafter also referred to as SS circuit). That is, first, the NS circuit starts supplying power safely in a low power state while avoiding a large current exceeding the allowable current value from flowing, and then, according to the power request, by the switching means. , Switching to the SS circuit can supply a large amount of power.

  In this case, the secondary side controls the load resistance value when the load is viewed from the secondary coil, so that the load from the primary coil to the load via the secondary coil is not controlled. Secondary side control means for controlling power supply for contact is provided. The primary-side control means controls the switching means based on the primary-side transmitted power for performing the non-contact power supply, and switches to the non-resonant circuit or the resonant circuit.

  In this way, by providing control means on each of the primary side and the secondary side, the primary side does not exchange information such as power supply information, that is, the state of the secondary side is determined. Without knowing, it is possible to determine whether or not to switch to the non-resonant circuit or the resonant circuit based on the transmitted power to be monitored. As a result, the non-contact power supply can be controlled easily and appropriately.

  Specifically, when the contactless power supply is started in a state where the primary side is switched to the non-resonant circuit, the primary-side control unit is configured to perform the following operation when the transmitted power reaches a predetermined power value. The switching means may be controlled to switch from the non-resonant circuit to the resonant circuit.

  That is, after the switching means switches from the non-resonance circuit to the resonance circuit, the secondary side control means receives power on the secondary side by controlling to increase the load resistance value. The received power may be increased.

  The primary-side control means changes the non-resonant circuit to the resonant circuit when the transmitted power is such that the received power decreases by a predetermined amount before and after switching from the non-resonant circuit to the resonant circuit. Switch.

  Thus, the secondary side control means detects that the predetermined amount of the received power is reduced, and determines that the primary side circuit has been switched from the non-resonant circuit to the resonant circuit, and performs desired control. Can be done. In addition, since the non-resonant circuit is switched to the resonant circuit so that the received power is reduced by a predetermined amount, it is possible to avoid the load-side voltage and current from exceeding allowable values before and after switching.

  In addition, after switching from the non-resonant circuit to the resonant circuit, when the secondary control means is controlled to decrease the load resistance value with a decrease in power demand from the load, The primary-side control means controls the switching means when the transmission power is such that the received power is reduced by the predetermined amount before and after switching from the resonance circuit to the non-resonance circuit, so that the resonance A circuit may be switched to the non-resonant circuit.

  Even in this case, the secondary side control means determines that the primary side circuit has been switched from the resonant circuit to the non-resonant circuit by detecting a decrease in the predetermined amount of the received power, and performs a desired control. Can be performed. Further, since the resonance circuit is switched to the non-resonance circuit so that the received power is reduced by a predetermined amount, it is possible to avoid the load-side voltage and current from exceeding allowable values before and after switching.

  Then, the secondary side control means starts from an initial state in which the load resistance value becomes substantially infinite in response to an increase in the power demand in a state in which the secondary side control unit is switched to the non-resonant circuit, and with the passage of time. Thus, the non-contact power supply is controlled by controlling the load resistance value to be lowered. Then, after switching from the non-resonant circuit to the resonant circuit, the non-contact power supply is controlled by controlling the load resistance value to increase with time in response to an increase in the power demand. After that, the non-contact power supply is controlled so that the load resistance value decreases with the passage of time in response to the decrease in the power requirement. Furthermore, after switching from the resonant circuit to the non-resonant circuit, the non-contact power supply is controlled by controlling the load resistance value to increase with time.

  Thus, the power supplied to the load can be increased smoothly by starting from the power supply by the NS circuit and then switching to the power supply by the SS circuit. Further, just before the power supply to the load is finished, the primary side current (transmission current) is restored by returning from the SS circuit to the NS circuit in order to reduce the power supplied to the load. It is possible to supply power in a low power state without increasing the power. As a result, the contactless power supply can be easily and appropriately controlled from the start to the end of the contactless power supply to the load.

  On the other hand, in the power supply system, it is possible to supply power without contact without switching between the NS circuit and the SS circuit. In this case, the power supply system may have the following configuration.

  That is, when the transmitted power is within the control range of the transmitted power by the non-resonant circuit, the primary-side control means causes the primary-side circuit to be switched to the non-resonant without switching by the switching means. Keep in circuit. Then, the secondary side control means starts from an initial state where the load resistance value becomes substantially infinite in response to the increase in the power demand, so that the load resistance value decreases with time. Then, the non-contact power supply is controlled, and thereafter, the non-contact power supply is controlled so that the load resistance value increases with time with respect to the decrease in the power demand.

  Even in this case, the contactless power supply can be easily and appropriately controlled from the start to the end of the contactless power supply to the load.

  The secondary control means determines that the non-resonance circuit or the resonance circuit has been switched by the switching means when the predetermined amount of the received power is reduced, and the determination result is Based on this, the non-contact power supply may be controlled. Thereby, it is possible to easily determine the switching of the non-resonant circuit or the resonant circuit on the secondary side.

  Further, the primary side resonance circuit includes the primary side coil and a primary side capacitor, and the switching unit is controlled by the primary side control unit and the primary side switch and the first side circuit. It may be a changeover switch that switches connection with the secondary side capacitor or bypass of the primary side capacitor. Thereby, the primary side can be switched to the non-resonant circuit or the resonant circuit with a simple configuration.

  Furthermore, it is only necessary to connect a series circuit of a resistor and a short-circuiting switch that is turned on / off by the control from the primary side control means to both ends of the primary side capacitor. Thereby, when switching from the resonant circuit to the non-resonant circuit, the charge stored in the primary-side capacitor can be quickly discharged by the resistor by turning on the short-circuit switch. As a result, when the non-resonance circuit or the resonance circuit is switched by the switching means, the occurrence of welding of the contact of the changeover switch due to the generation of an arc due to the electric charge accumulated in the primary side capacitor is avoided. Can do.

  Further, a series circuit of a secondary switch and a resistor having a resistance value set to an arbitrary fixed value within a range that the load resistance value can take is connected to the secondary coil, The secondary side control means may control conduction between the secondary side coil and the resistor by turning on and off the secondary side switch. In this way, it is possible to accurately determine whether or not the non-contact power supply is possible by using the resistor having a resistance value set to an arbitrary fixed value within a possible range of the load resistance value. can do.

  According to the present invention, there is no exchange of power supply information between the primary side that is the power supply side and the secondary side that is the power reception side, and there is no inverter on the primary side. To the secondary load.

It is a circuit diagram of the electric power supply system concerning this embodiment. 2A is a circuit diagram showing an SS circuit, and FIG. 2B is a circuit diagram showing a T-type equivalent circuit of the SS circuit of FIG. 2A. 3A is a circuit diagram showing an NS circuit, and FIG. 3B is a circuit diagram showing a T-type equivalent circuit of the NS circuit of FIG. 3A. It is a figure which shows the transmission current characteristic and transmission power characteristic of a primary side. It is a figure which shows the receiving current characteristic and receiving power characteristic of a secondary side. It is a figure which shows the primary side data table produced | generated using the transmission current characteristic and transmission power characteristic of FIG. It is a figure which shows the secondary side data table produced | generated using the receiving current characteristic and receiving power characteristic of FIG. It is a flowchart which shows operation | movement of the electric power supply system of FIG. It is a flowchart which shows the operation | movement of the primary side of FIG. It is a flowchart which shows the operation | movement of the secondary side of FIG. It is a flowchart which shows the operation | movement of the secondary side of FIG. It is a timing chart which shows an initial process. It is a timing chart which shows the charge process to a battery. It is a circuit diagram which shows the modification of FIG.

  Hereinafter, a preferred embodiment of a power supply system according to the present invention will be exemplified and described with reference to the accompanying drawings.

[Configuration of this embodiment]
As shown in FIG. 1, the power supply system 10 according to the present embodiment is a system that performs non-contact power supply (non-contact power transmission) from the primary side 12 that is the power supply side to the secondary side 14 that is the power reception side. .

  The primary side 12 has a changeover switch 15 as a switching means, and is connected to the AC power supply 16 via the primary side switch 18 and the changeover switch 15 (and the primary side resonance capacitor 21). The coil 20 is connected. The changeover switch 15 is a relay switch (three-point switch), the c contact is connected to the AC power supply 16 via the primary side switch 18, the b contact is connected to one end of the primary side resonance capacitor 21, and the a contact Are connected to the other end of the primary side resonance capacitor 21 and the primary side coil 20.

  Between the primary side switch 18 and the contact c of the changeover switch 15, a primary side current sensor 22 for detecting a current I1 flowing through the primary side coil 20 (hereinafter also referred to as a transmission current I1) is connected. Yes. Further, a primary side voltage sensor 24 that detects a voltage V <b> 1 (hereinafter also referred to as a transmission voltage V <b> 1) generated in the primary side coil 20 includes a primary side coil 20 (a primary side resonance capacitor 21) and a changeover switch 15. And connected in parallel. The changeover switch 15 connects the c contact to the a contact or the b contact based on a control signal from the primary controller 26 as the primary control means. When the c contact and the a contact are connected, the primary side resonance capacitor 21 is bypassed (bypass state). On the other hand, when the c contact and the b contact are connected, the bypass state is canceled and the primary side switch 18 and the primary side resonance capacitor 21 are connected (connected state). The primary side switch 18 is a relay that is turned on / off based on a control signal from a primary side controller 26 as primary side control means.

  In this case, the primary side current sensor 22 sequentially detects the transmission current I1, and sequentially outputs a detection signal corresponding to the detected transmission current I1 to the primary side controller 26. The primary side voltage sensor 24 sequentially detects the transmission voltage V1 and sequentially outputs a detection signal corresponding to the detected transmission voltage V1 to the primary side controller 26. The primary side controller 26 has a primary side data table 28 to be described later, and based on each input detection signal (transmission current I1, transmission voltage V1), the primary side 12 power P1 (hereinafter referred to as transmission power P1). And the switching of the changeover switch 15 and the on / off of the primary side switch 18 are controlled based on the primary side data table 28, the transmission current I1, and the transmission power P1. The non-contact power feeding from the secondary side to the secondary side 14 is controlled.

  That is, the primary-side controller 26 switches the changeover switch 15 to the connection between the c-contact and the a-contact to place the primary-side resonant capacitor 21 in a bypass state, and the AC power supply 16 and 1 via the primary-side switch 18. The secondary coil 20 is connected, and the primary side 12 functions as a non-resonant circuit. Further, the primary side controller 26 releases the primary side resonance capacitor 21 from the bypass state (sets the connection state) by switching the changeover switch 15 to the connection between the c contact and the b contact, and the primary side switch 18 and The AC power supply 16 is connected to the primary side resonance capacitor 21 and the primary side coil 20 via the changeover switch 15 so that the primary side 12 functions as a resonance circuit.

  The secondary side 14 is, for example, an electric vehicle 30, and a secondary battery battery 34 as a load is connected to the secondary coil 32. The secondary side coil 32 is a power receiving side pad arranged with a predetermined gap with respect to the primary side coil 20 that is a power transmitting side pad, and the power supplied from the primary side coil 20 in a non-contact manner. Receive power.

  On the secondary side 14, an OBC 38 (on-board charger) is connected in parallel between the secondary coil 32 and the battery 34 via a secondary resonance capacitor 36. Therefore, the secondary side 14 is configured to include a resonance circuit including the secondary side coil 32, the secondary side resonance capacitor 36, and the like. Therefore, in the power supply system 10, the primary side resonant capacitor 21 is bypassed by switching the changeover switch 15, so that the secondary side coil 32 is moved from the primary side coil 20 to the non-contact power feeding of the NS circuit. Via the battery 34. Further, in the power supply system 10, the primary side resonance capacitor 21 is connected by switching the changeover switch 15, so that the secondary side coil 32 is moved from the primary side coil 20 to the contactless power feeding of the SS circuit. Thus, the battery 34 can be charged.

  The OBC 38 is an in-vehicle charger that includes a contact charging port 40 and charges the battery 34 with electric power supplied from the primary side coil 20 via the secondary side coil 32 in a non-contact manner. Alternatively, the battery 34 is charged with power supplied from an external power source (not shown) through the contact charging port 40. Note that switching between the two charging methods is performed by switching control within the OBC 38.

  A secondary voltage sensor 42 that detects a voltage V <b> 2 (hereinafter also referred to as a received voltage V <b> 2) generated in the secondary coil 32 is parallel to the secondary coil 32 and the secondary resonance capacitor 36. It is connected. Connected between the rear end of the secondary side resonance capacitor 36 and the OBC 38 is a secondary side current sensor 44 that detects a current I2 flowing through the secondary side coil 32 (hereinafter also referred to as a received current I2). . Further, a charging current sensor 46 that detects a current I 3 (hereinafter also referred to as a charging current I 3) that flows from the OBC 38 to the battery 34 is connected between the OBC 38 and the battery 34. Furthermore, a charging voltage sensor 48 that detects a voltage V3 of the battery 34 (hereinafter also referred to as a charging voltage V3) is connected to the battery 34 in parallel.

  In this case, the secondary current sensor 44 sequentially detects the received current I2, and sequentially outputs a detection signal corresponding to the detected received current I2 to the OBC 38. Further, the secondary side voltage sensor 42 sequentially detects the power reception voltage V2, and sequentially outputs a detection signal corresponding to the detected power reception voltage V2 to the OBC 38. The charging current sensor 46 sequentially detects the charging current I3, and sequentially outputs a detection signal corresponding to the detected charging current I3 to the OBC 38. The charging voltage sensor 48 sequentially detects the charging voltage V3, and sequentially outputs a detection signal corresponding to the detected charging voltage V3 to the OBC 38.

  In the OBC 38, the secondary side switch 50 and the resistor 52, which are relays, from the secondary side coil 32 and the secondary side resonance capacitor 36 toward the battery 34, a rectifier circuit 54, a first smoothing circuit 56, The voltage conversion circuit 58, the second smoothing circuit 60, and the DC / DC converter 62 are connected in parallel to the secondary coil 32. Further, in the OBC 38, the rectifier circuit 54 is connected to the contact charging port 40 between the secondary side resonance capacitor 36 and the rectifier circuit 54, or the rectifier circuit 54 is connected to the secondary side resonance capacitor 36 and the secondary side. An input changeover switch 64 is provided for switching between switching to a series circuit of the switch 50 and the resistor 52.

  Further, the OBC 38 is provided with a secondary side controller 66 as secondary side control means for controlling the secondary side switch 50 and the input changeover switch 64 which are relays, the voltage conversion circuit 58 and the DC / DC converter 62. It has been. The secondary side controller 66 has a secondary side data table 68 described later. The secondary controller 66 calculates the power P2 of the secondary side 14 (hereinafter also referred to as received power P2) based on each detection signal (received current I2, received voltage V2) input to the OBC 38. From the primary side 12 by controlling the secondary side switch 50, the input changeover switch 64, the voltage conversion circuit 58 and the DC / DC converter 62 based on the secondary side data table 68 and the received current I2 and the received power P2. Controls non-contact power feeding to the secondary side 14.

  In the OBC 38, the secondary side switch 50 is turned on / off by a control signal from the secondary side controller 66. The resistor 52 has a resistance value set to an arbitrary fixed value (for example, a relatively small current of 2 is a value within a possible range of the load resistance value Rz when the battery 34 is viewed from the secondary coil 32. This is a resistor having a resistance value on the higher side of values within a range that can be taken by the load resistance value Rz flowing in the circuit on the next side 14.

  Note that the load resistance value Rz is more accurately the resistance of the load impedance on the right side of the secondary side resonance capacitor 36 on the secondary side 14 when the battery 34 is viewed from the secondary side coil 32 in FIG. Minute (real component).

  The rectifier circuit 54 is a diode bridge composed of four diodes 70, and when the secondary side resonance capacitor 36 and the rectifier circuit 54 are connected by the input changeover switch 64, the secondary side coils 32 and 2. The received voltage V2 generated in the secondary resonance capacitor 36 is rectified (converted into a pulsating voltage). The first smoothing circuit 56 includes a capacitor 72 and generates a DC voltage by smoothing the pulsating voltage.

  The voltage conversion circuit 58 is a boost chopper having a transistor 74 as a switching element, a coil 76, and a diode 78, and boosts a DC voltage. Note that the voltage conversion circuit 58 may have a function of a power factor correction circuit as necessary.

  In this case, a series circuit of the coil 76 and the transistor 74 is connected to the capacitor 72 in parallel. That is, the collector terminal of the transistor 74 is connected to one end of the capacitor 72 via the coil 76, and the emitter terminal is connected to the other end of the capacitor 72. The collector terminal of the transistor 74 is connected to the anode terminal of the diode 78. The transistor 74 is turned on and off between the collector terminal and the emitter terminal based on a control signal supplied from the secondary controller 66 to the base terminal. The voltage conversion circuit 58 can also employ a step-down chopper, but in the following description, a case where it is a step-up chopper as shown in FIG. 1 will be described.

  The second smoothing circuit 60 has a capacitor 80. The capacitor 80 is connected in parallel between the cathode terminal of the diode 78 and the emitter terminal of the transistor 74, and smoothes the DC voltage boosted by the voltage conversion circuit 58. The DC / DC converter 62 has an input side connected in parallel with the capacitor 80, and an output side connected in parallel with the battery 34. The DC / DC converter 62 converts the DC voltage smoothed by the second smoothing circuit 60 into a desired voltage so that the charging voltage V3 and the charging current I3 of the battery 34 have desired values.

[Description of NS circuit and SS circuit]
Next, a circuit system of the power supply system 10 will be described with reference to FIGS. 2A to 3B.

  FIG. 2A shows a simplified circuit diagram when the power supply system 10 is an SS circuit. 2B shows a circuit diagram of a T-type equivalent circuit of the SS circuit of FIG. 2A. On the other hand, FIG. 3A shows a simplified circuit diagram when the power supply system 10 is an NS circuit. FIG. 3B shows a circuit diagram of a T-type equivalent circuit of the NS circuit shown in FIG. 3A.

In the SS circuit of FIGS. 2A and 2B, impedance (primary side impedance) Zin1 when the battery 34 is viewed from the AC power supply 16 is expressed by the following equation (1).
Zin1 = V1 / I1 = {r1 × (r2 + RL) + ω ² × Lm ² }
/ (R2 + RL) (1)

  Here, r1 is the internal resistance value of the primary side 12, r2 is the internal resistance value of the secondary side 14, RL is the load resistance value Rz of the secondary side 14, ω is the angular frequency, and Lm is the primary side. This is a mutual inductance between the coil 20 and the secondary coil 32.

On the other hand, in the NS circuit of FIGS. 3A and 3B, the primary side impedance Zin1 is expressed by the following equation (2).
Zin1 = V1 / I1 = {(r1 + j × ω × L1) × (r2 + RL)
+ Ω ² × Lm ² } / (r2 + RL) (2)

  Note that L1 is the self-inductance of the primary coil 20, and j is an imaginary unit. 2A to 3B, C1 is a capacitance of the primary side resonance capacitor 21, C2 is a capacitance of the secondary side resonance capacitor 36, L1 is an inductance of the primary side coil 20, and L2 is 2 This is the inductance of the secondary coil 32.

  Here, although the NS circuit and the SS circuit have substantially the same efficiency, the SS circuit is larger in the transmission power P1 than the NS circuit.

  Further, from the equation (1), when the load resistance value RL = ∞ (infinity), Zin1 = V1 / I1 = r1. In this case, when the non-contact power supply is started from the state where the load resistance value RL is infinite, the large primary current I1 = V1 / r1 due to the low internal resistance value r1 is instantly turned on at the moment when the primary switch 18 is turned on. Will flow. As a result, both the primary side 12 and the secondary side 14 may exceed the allowable current value of the distribution facility.

  Therefore, the non-contact power supply by the SS circuit is suitable for high-power transmission, but cannot be used from the state where the load resistance value RL = ∞.

  On the other hand, in the NS circuit, from the formula (2), when the load resistance value RL = ∞, Zin1 = V1 / I1 = r1 + j × ω × L1. In this case, I1 = V1 / (r1 + j × ω × L1). For this reason, if the inductance L1 is sufficiently high, the power factor is lowered and the transmission current I1 (effective current) can be kept low due to the high j × ω × L1 with respect to the low internal resistance value r1. For this reason, in the NS circuit, the primary side switch 18 can be turned on and the low contact power supply can be started from the low power state.

  Therefore, as will be described later, in the non-contact power supply by the power supply system 10, in the first low power state in which the AC power supply 16 is turned on and the control of the primary side 12 and the secondary side 14 is started, the NS circuit Thus, non-contact power feeding from the primary side 12 to the secondary side 14 is performed, and thereafter, non-contact power feeding is performed from the primary side 12 to the secondary side 14 in a high power state by the SS circuit. The switching between the NS circuit and the SS circuit is performed by switching the primary side resonance capacitor 21 to the connected state or the bypass state by the changeover switch 15.

[Primary data table 28 and secondary data table 68]
Next, the primary side data table 28 and the secondary side data table 68 will be described with reference to FIGS.

  The primary side data table 28 (see FIG. 1) indicates whether the primary side 12 and the secondary side 14 are normal, specifically, from the primary side coil 20 to the secondary side coil 32. Used when the primary-side controller 26 determines from the transmission current I1 and the transmission power P1 on the primary side 12 without knowing the situation on the secondary side 14 whether or not the non-contact power supply is normally performed. Is done. On the other hand, the secondary data table 68 indicates whether or not the mutual state of the primary side 12 and the secondary side 14 is normal, specifically, non-contact from the primary side coil 20 to the secondary side coil 32. This is used when the secondary-side controller 66 determines from the received current I2 and the received power P2 on the secondary side 14 without knowing the situation on the primary side 12 whether or not the power supply is normally performed.

  In this case, the primary data table 28 and the secondary data table 68 are obtained in advance by experiments as described below, and are stored (set) in the primary controller 26 and the secondary controller 66.

  In this experiment, the primary side coil 20 and the secondary side coil 32 are in normal positions facing each other with a predetermined gap (interval), and the primary side switch 18 and the secondary side switch 50 are each turned on. In this case, the voltage is supplied from the AC power supply 16 to the primary coil 20 and the electric power is supplied from the primary coil 20 to the secondary coil 32 in a non-contact manner. At that time, a load resistance device such as an electronic load device (not shown) is attached instead of the OBC 38, and the resistance value (load resistance value Rz) is changed from approximately infinity (∞) to a low value (resistance value near 0). Then, the transmission current I1, the transmission voltage V1, the reception current I2, and the reception voltage V2 corresponding to each changed resistance value are acquired.

  In the following description, a case where the resistance value of the load resistance device is the load resistance value Rz (RL) will be described. In addition, as described above, the transmission current I1, the transmission voltage V1, the reception current I2, and the reception voltage V2 are the primary side current sensor 22, the primary side voltage sensor 24, the secondary side current sensor 44, and the secondary side, respectively. It is detected by the voltage sensor 42.

  The transmission power P1 is obtained by multiplying the transmission current I1, the transmission voltage V1, and the power factor cos θ1 of the primary side 12 for each load resistance value Rz. On the other hand, the received power P2 is obtained by multiplying the received current I2, the received voltage V2, and the power factor cos θ2 of the secondary side 14 for each load resistance value Rz. Actually, the power transmission current I1, the power transmission voltage V1, the power reception current I2, and the power reception voltage V2 were acquired at a sampling speed sufficiently faster than the power transmission / reception frequency between the primary side coil 20 and the secondary side coil 32. An integral value of instantaneous power obtained by multiplying the current and voltage is calculated as transmitted power P1 and received power P2.

  Further, in the power supply system 10, the switch 15 is switched to an NS circuit or an SS circuit. Therefore, in the following description, each current, each voltage and each power obtained in the NS circuit will be described with the letters “NS”, while each current obtained in the SS circuit, The voltage and each power may be described with the letters “SS”.

  FIG. 4 illustrates a characteristic (transmission current characteristic) indicating the relationship between the transmission current I1 and the load resistance value Rz and a characteristic (transmission power characteristic) indicating the relationship between the transmission power P1 and the load resistance value Rz. Yes.

  As shown in FIG. 4, in the NS circuit, the transmission current characteristic shows that the transmission current I1NS increases to the maximum transmission current I1NSmax as the load resistance value Rz decreases, and the load resistance value at the maximum transmission current I1NSmax With a resistance value lower than Rz, the transmission current I1NS has a characteristic of decreasing. Further, the transmission power characteristic indicates that the transmission power P1NS increases to the maximum transmission power P1NSmax as the load resistance value Rz decreases, and the transmission power P1NS has a resistance value lower than the load resistance value Rz at the maximum transmission power P1NSmax. Has the property of decreasing.

  On the other hand, as shown in FIG. 4, in the SS circuit, the transmission current characteristic has a characteristic that the transmission current I1SS decreases as the load resistance value Rz decreases. The transmission power characteristic has a characteristic that the transmission power P1SS decreases as the load resistance value Rz decreases. That is, in the SS circuit, as described above, the transmission current I1SS and the transmission power P1SS increase as the load resistance value Rz increases.

  Note that a predetermined point for switching from the NS circuit to the SS circuit is set on the transmission power characteristic of the NS circuit obtained in this experiment. In FIG. 4, the predetermined transmission power P1NS at this point is P1NSth. Further, a predetermined point for switching from the SS circuit to the NS circuit is set on the transmission power characteristic in the SS circuit. This point is set corresponding to the point at which the SS circuit is switched to the NS circuit on the received power characteristic in the SS circuit described later. In FIG. 4, the predetermined transmission power P1SS at this point is P1SSth.

  FIG. 5 shows a characteristic (received current characteristic) indicating the relationship between the received current I2 and the load resistance value Rz, and a characteristic (received power characteristic) indicating the relationship between the received power P2 and the load resistance value Rz. Yes.

  As shown in FIG. 5, in the NS circuit, the received current characteristic has a characteristic that the received current I2NS increases to the maximum received current I2NSmax as the load resistance value Rz decreases. The received power characteristic indicates that the received power P2NS increases to the maximum received power P2NSmax as the load resistance value Rz decreases, and the received power P2NS is lower than the load resistance value Rz at the maximum received power P2NSmax. Has the property of decreasing.

  On the other hand, in the SS circuit, the received current characteristic originally has a constant current characteristic. Therefore, the received current I2SS is constant regardless of the load resistance value Rz. However, as shown in FIG. 5, in the actual electromagnetic circuit, the received current I2SS slightly decreases as the load resistance value Rz increases due to loss. Have the following characteristics: The received power characteristic has a characteristic that the received power P2SS increases as the received voltage V2SS increases as the load resistance value Rz increases. That is, in the SS circuit, as described above, the received power P2SS increases as the load resistance value Rz increases. In FIG. 5, P2SSmax is a predetermined maximum received power set from the characteristics of the electromagnetic circuit.

  Note that a predetermined point for switching from the NS circuit to the SS circuit is set on the received power characteristic of the NS circuit obtained in this experiment. In FIG. 5, the predetermined received power P2NS at this point is P2NSth. This point is set corresponding to a point (transmission power P1NSth) at which the NS circuit in FIG. 4 is switched to the SS circuit. Here, a reduction amount of the received power P2 when switching from the NS circuit to the SS circuit is a predetermined reduction amount ΔP2. In addition, on the received power characteristic in the SS circuit, a predetermined point is set so that the amount of decrease in the received power P2 when switching from the SS circuit to the NS circuit becomes the predetermined decrease amount ΔP2. . In FIG. 5, the predetermined received power P2SS at this point is P2SSth.

  By the way, as described above, the positional deviation between the primary coil 20 and the secondary coil 32 occurs with respect to the normal position where the primary coil 20 and the secondary coil 32 face each other. Depending on the surrounding environment such as temperature or the like, the transmission current characteristic, the transmission power characteristic, the reception current characteristic, and the reception power characteristic may vary.

  Therefore, considering such misalignment, gap difference, ambient temperature, ambient environment, etc., each characteristic shown in FIGS. 4 and 5 is centered on each characteristic as shown in FIGS. A certain permissible range is set, each characteristic in the set range is measured in advance, and each characteristic and each permissible range are set as the primary side data table 28 and the secondary side data table 68 as the primary side controllers 26 and 2. Each secondary controller 66 is set (stored) in advance.

  FIG. 6 reflects a certain allowable range (transmission current allowable range ΔI1NS, ΔI1SS) on the transmission current characteristic and reflects a certain allowable range (transmission power allowable range ΔP1NS, ΔP1SS) on the transmission power characteristic. The primary side data table 28 is illustrated. FIG. 7 reflects a certain allowable range (received current allowable range ΔI2NS, ΔI2SS) for the received current characteristic and a fixed allowable range (received power allowable range ΔP2NS, ΔP2SS) for the received power characteristic. The secondary data table 68 is illustrated.

  Actually, the transmission power P1NS and P1SS and the received power P2NS and P2SS are obtained by the following arithmetic processing in the control processing. First, the primary controller 26 has instantaneous values (detected values) of the transmission current I1 (I1NS, I1SS) and the transmission voltage V1 (V1NS, V1SS) at a predetermined sampling interval corresponding to a frequency sufficiently higher than the transmission / reception frequency. Get each. Next, the primary-side controller 26 calculates an instantaneous value (instantaneous power) of the transmission power P1 (P1NS, P1SS) for each sampling from the acquired instantaneous values of the transmission current I1 and the transmission voltage V1. Next, the primary side controller 26 adds the instantaneous power of the transmission power P1 for one period corresponding to the frequency of the AC power supply 16, and divides the added instantaneous power by the period, thereby obtaining an average value of the instantaneous power. (Average power) is calculated. Thereby, the primary side controller 26 sets the calculated average power as the transmission power P1 (P1NS, P1SS).

  On the other hand, the secondary controller 66 has instantaneous values (detected values) of the received current I2 (I2NS, I2SS) and the received voltage V2 (V2NS, V2SS) at a predetermined sampling interval corresponding to a frequency sufficiently higher than the power transmission / reception frequency. Get each. Next, the secondary-side controller 66 calculates an instantaneous value (instantaneous power) of the received power P2 (P2NS, P2SS) for each sampling from the acquired instantaneous values of the received current I2 and the received voltage V2. Next, the secondary-side controller 66 adds the instantaneous power of the received power P2 for one cycle corresponding to the frequency of the AC power supply 16, and divides the added instantaneous power by the cycle to obtain an average value of the instantaneous power. (Average power) is calculated. Thereby, the secondary controller 66 sets the obtained average power as the received power P2 (P2NS, P2SS).

  In the power supply system 10, the secondary side switch 50 is turned off and the secondary side resonance capacitor 36 and the rectifier circuit 54 are connected by the input changeover switch 64. When the primary side switch 18 is turned on and the transistor 74 is turned on and off by PWM (Pulse Width Modulation) control by the secondary side controller 66, the primary side coil 20 is connected to the battery 34 via the secondary side coil 32. Non-contact power feeding (charging) is performed.

  In this case, the primary side controller 26 and the secondary side controller 66 can perform the following processing using the primary side data table 28 and the secondary side data table 68, respectively.

  That is, when the changeover switch 15 is switched so as to bypass the primary side resonance capacitor 21 and the power supply system 10 is an NS circuit, the primary side controller 26, as shown in FIG. Based on the transmission current I1NS detected by the primary current sensor 22 using the allowable transmission current range ΔI1NS in the secondary data table 28, the ranges ΔRzi11 and ΔRzi12 of the load resistance value Rz within the allowable transmission current range ΔI1NS are obtained. calculate. The primary-side controller 26 calculates transmission power P1NS based on the transmission current I1NS detected by the primary-side current sensor 22 and the transmission voltage V1NS detected by the primary-side voltage sensor 24, and the primary-side data Based on the calculated transmission power P1NS, the range ΔRzp1 of the load resistance value Rz within the transmission power allowable range ΔP1NS is calculated using the transmission power allowable range ΔP1NS in the table 28.

  If there is a matching region between the range ΔRzi11, ΔRzi12 of the load resistance value Rz calculated based on the transmission current I1NS and the range ΔRzp1 of the load resistance value Rz calculated based on the transmission power P1NS, 1 Including the mutual coupling relationship between the secondary coil 20 and the secondary coil 32, the primary side 12 and the secondary side 14 are in a normal state, and contactless power feeding from the primary side 12 to the secondary side 14 is performed. It is determined that it is in a normal state. In FIG. 6, there are two ranges of the load resistance value Rz based on the transmission current I1NS, the right range ΔRzi11 and the left range ΔRzi12 across the maximum transmission current I1NSmax. In this case, a region where the part of the right range ΔRzi11 overlaps the range ΔRzp1 based on the transmission power P1NS (range ΔRzp1) is a matching region.

  On the other hand, if there is no matching area between the ranges ΔRzi11 and ΔRzi12 of the load resistance value Rz calculated based on the transmission current I1NS and the range ΔRzp1 of the load resistance value Rz calculated based on the transmission power P1NS, 1 Including the mutual coupling relationship between the secondary coil 20 and the secondary coil 32, the primary side 12 and the secondary side 14 are in an abnormal state, and contactless power feeding from the primary side 12 to the secondary side 14 is performed. It is determined that the state is not performed normally.

  Further, as shown in FIG. 7, the secondary-side controller 66 uses the power-receiving current allowable range ΔI2NS in the secondary-side data table 68 to receive power based on the power-receiving current I2NS detected by the secondary-side current sensor 44. A range ΔRzi2 of the load resistance value Rz that falls within the current allowable range ΔI2NS is calculated. The secondary-side controller 66 calculates the received power P2NS based on the received current I2NS detected by the secondary-side current sensor 44 and the received voltage V2NS detected by the secondary-side voltage sensor 42, and the secondary-side data Based on the calculated received power P2NS using the received power allowable range ΔP2NS in the table 68, a range ΔRzp2 of the load resistance value Rz within the received power allowable range ΔP2NS is calculated.

  If there is a matching region between the range ΔRzi2 of the load resistance value Rz calculated based on the received current I2NS and the range ΔRzp2 of the load resistance value Rz calculated based on the received power P2NS, the primary Including the mutual coupling relationship between the side coil 20 and the secondary coil 32, the primary side 12 and the secondary side 14 are in a normal state, and non-contact power feeding from the primary side 12 to the secondary side 14 is normal. It is determined that it is in a state that can be performed. In FIG. 7, a region where the range ΔRzi2 based on the received current I2NS and a part of the range ΔRzp2 based on the received power P2Ns overlap each other is a matching region.

  On the other hand, if there is no matching region between the range ΔRzi2 of the load resistance value Rz calculated based on the received current I2NS and the range ΔRzp2 of the load resistance value Rz calculated based on the received power P2NS, the primary Including the mutual coupling relationship between the side coil 20 and the secondary coil 32, the primary side 12 and the secondary side 14 are in an abnormal state, and non-contact power feeding from the primary side 12 to the secondary side 14 is normal. It is determined that the state has not been completed.

  On the other hand, in the case where the power supply system 10 is an SS circuit by the changeover switch 15 switching the primary side resonance capacitor 21 to the connected state, the term “NS” is used for the above description. Is replaced with the word “SS”, the processing using the primary side data table 28 and the secondary side data table 68 in the primary side controller 26 and the secondary side controller 66 in the SS circuit will be described. Therefore, the description of the processing of the SS circuit is omitted.

[Operation of this embodiment]
The operation of the power supply system 10 configured as described above will be described with reference to FIGS. In this description of the operation, it will be described with reference to FIGS. 1 to 7 as necessary.

  Here, the control target is to set the charging voltage V3 of the battery 34, which is a secondary battery, to the maximum voltage value at which charging can be performed safely, that is, the charging end voltage V3obj, from the primary side 12 to the secondary side. A case where contactless power feeding is performed will be described. The maximum current value that can be safely charged is a value that varies depending on the SOC (State of Charge), and is assumed to be the target charging current I3obj.

  In addition, the secondary controller 66 turns on and off the transistor 74 by PWM control. Here, it is assumed that the period of the control signal by PWM control is τ and the on time of the transistor 74 is Ton. Note that by controlling the on-time Ton, the load resistance value Rz can be changed from approximately infinity (∞) to near 0, and the received current I2 (I2NS, I2SS) and received power shown in FIGS. P2 (P2NS, P2SS) can be controlled.

  In the following description, the changeover switch 15 switches the primary-side resonant capacitor 21 to either the bypass state or the connected state according to the power request from the battery 34 (for example, SOC, charging voltage V3, charging current I3). A case where the NS circuit or the SS circuit is switched by switching will be described. Therefore, in order to avoid complication of explanation, for the transmission current I1, the transmission voltage V1, the transmission power P1, the reception current I2, the reception voltage V2, and the reception power P2 in the operation of the NS circuit or the SS circuit, The description may be made without adding the word “NS” indicating that the NS circuit is in operation or the word “SS” indicating that the NS circuit is in operation. Keep in mind.

  8 to 11 are flowcharts of control of the primary side 12 and the secondary side 14 (see FIG. 1). In FIG. 8, the left flow shows the control on the primary side 12, and the right flow shows the control on the secondary side 14. 9 shows the continuation of the control on the primary side 12 in FIG. 8, while FIGS. 10 and 11 show the continuation of the control on the secondary side 14 in FIG.

  First, in order to charge the battery 34, the driver stops the electric vehicle 30 at a position where the primary side coil 20 (power transmission side pad) and the secondary side coil 32 (power reception side pad) face each other, and gets off. In this case, the driver confirms whether or not there is a foreign object or the like between the two pads at a position where the two pads face each other.

  Here, in step S201 in FIG. 8, the driver turns on a switch (not shown) of the OBC 38 of the electric vehicle 30 to activate the OBC 38.

  Thereby, in step S202, the secondary side controller 66 of the OBC 38 supplies a control signal to the input changeover switch 64 so that the secondary side resonance capacitor 36 and the rectifier circuit 54 are not connected, while the secondary side controller 66 A control signal is supplied to the switch 50 to turn it on.

  In the next step S203, the secondary-side controller 66 checks whether or not the battery 34 is in a chargeable state. Specifically, the secondary controller 66 has V3 <V3obj and SOC <100% based on the charging voltage V3 detected by the charging voltage sensor 48 and the charging current I3 detected by the charging current sensor 46. It is determined whether or not. If the determination result is affirmative in step S203 (step S203: YES), the secondary side 14 proceeds to the next step S204 and waits.

  On the other hand, on the primary side 12, in step S101, the driver turns on the primary controller 26 (not shown) to activate the primary controller 26. The primary side controller 26 supplies a control signal to the changeover switch 15 to switch the primary side resonance capacitor 21 to the bypass state. Thereby, the primary side 12 is switched to a non-resonant circuit. That is, the power supply system 10 is switched to the NS circuit.

  Next, in step S102, the primary-side controller 26 supplies the control signal to the primary-side switch 18 to turn it on / off, whereby the alternating-current power from the alternating-current power supply 16 is changed to pulsed power (pulsed) that lasts for a short time. Power) to the primary coil 20. Thereby, the primary side coil 20 supplies pulse power to the secondary side coil 32 in a non-contact manner. As described above, in a state where the secondary side coil 32 faces the primary side coil 20 and is close to a predetermined position, due to the mutual inductance Lm between the primary side coil 20 and the secondary side coil 32, On the primary side 12 and the secondary side 14, prescribed transmission power P <b> 1 (P <b> 1 NS) and received power P <b> 2 (P <b> 2 NS) are generated.

  Therefore, in step S103, the primary controller 26 determines whether or not the transmission power P1 is a specified value based on the primary data table 28. Specifically, the primary side controller 26 refers to the load resistance value Rz based on the transmission current I1 (I1NS) detected by the primary side current sensor 22, and coordinates between the referenced load resistance value Rz and the transmission current I1. It is determined whether or not the value is within the transmission current allowable range ΔI1 (ΔI1NS) of the primary data table 28. Further, the primary side controller 26 calculates the transmission power P1 based on the transmission current I1 and the transmission voltage V1 (V1NS) detected by the primary side voltage sensor 24, and the load resistance based on the calculated transmission power P1. By further referring to the value Rz, it is determined whether or not the coordinate value of the transmission power P1 and the load resistance value Rz is within the transmission power allowable range ΔP1NS of the primary data table 28. Then, it is determined whether the referenced load resistance values Rz are substantially equal to each other and are substantially equal to the fixed resistance value of the resistor 52.

  When the determination result in step S103 is affirmative (step S103: YES), the primary controller 26 can supply power in a non-contact manner between the primary coil 20 and the secondary coil 32. It is determined that there is, and the process proceeds to the next step S104. In step S104, the primary controller 26 determines whether or not to repeat the processes in steps S102 and S103. When repeatedly performing (step S104: YES), the primary-side controller 26 returns to step S102 and performs the processes of steps S102 and S103 again.

  By repeatedly performing the processing of steps S102 to S104, as shown in FIG. 12, for example, pulsed transmission power P1 is generated within the period of T2 and T3 in the time of T1, and 2 from the primary side coil 20 Electric power is supplied to the secondary coil 32 without contact. In FIG. 12, the secondary controller 66 is activated at time t1 (step S201), the primary controller 26 is activated at time t2 (step S101), and within a time T1 from time t3 to time t4, The case where three pulsed transmission power P1 with pulse widths T4 and T5 is generated is illustrated. Further, when the pulsed transmission power P1 within the time T1 is regarded as a plurality of pulse waveforms, a pulse signal having a pattern arrangement of “10001000110000” is transmitted from the primary coil 20 to the secondary coil in the processes of steps S102 to S104. It can also be considered that it is transmitting to 32.

  At time t4, after the generation of the pulsed transmission power P1 is stopped (step S104: NO), the primary side 12 proceeds to the next step S105 and stands by.

  On the other hand, in step S <b> 204 of FIG. 8, the secondary controller 66 determines whether or not the secondary coil 32 has received pulsed power from the primary coil 20. When it is determined that the secondary coil 32 has received pulsed power (step S204: YES), in the next step S205, the secondary controller 66 determines that the secondary side 14 is connected to the primary side 12. Whether or not electric power can be received in a contactless manner by magnetic field coupling, and whether or not the secondary side 14 is a normal one that satisfies a predetermined specification as a counterpart of magnetic field coupling to the primary side 12 Perform authentication processing.

  In step S205, the following three determination processes (1) to (3) are performed in parallel or sequentially.

  (1) Referring to the secondary data table 68, the load resistance value Rz corresponding to the received current I2 (I2NS) is referred to. Next, the received power P2 (P2NS) is calculated based on the received voltage V2 (V2NS) and the received current I2, and the load resistance value Rz corresponding to the calculated received power P2 is obtained by referring to the secondary data table 68. Refer to Then, it is determined whether or not the obtained load resistance values Rz are substantially equal to each other and are substantially equal to the fixed resistance value of the resistor 52.

  (2) The power (received power P2) received by the secondary coil 32 when the power (transmitted power P1) is supplied to the primary coil 20 is referred to from the secondary data table 68. It is determined whether or not it is within the (received power allowable range ΔP2NS).

  (3) For a plurality of pulsed power supplied to the primary coil 20, the time (state) during which power is supplied is set to “1”, and the time (state) during which power is not supplied is set to “0”. The pattern arrangement when expressed, and a plurality of pulses received by the secondary coil 32 when the pulsed power of the pattern arrangement is fed from the primary coil 20 to the secondary coil 32 in a non-contact manner. For the received power P <b> 2, the pattern arrangement when the time (state) during which the specified power is supplied is expressed as “1” and the time (state) during which no power is supplied is expressed as “0”. It is determined whether or not they match.

  As an example, in the determination process of (3), when the pattern arrangement of the pulsed power of the primary side coil 20 is “10001000110000” shown in FIG. 12, the pattern arrangement of the received power P2 on the secondary side 14 is “10001000110000”. ”Is determined.

  In step S205, when the results of these three determination processes are all positive determination results (step S205: YES), the secondary-side controller 66 is supplied with power from the primary coil 20 in a non-contact manner. The power can be received by the secondary side coil 32 (the secondary side 14 is in a power receiving state), and the secondary side 14 is authorized as a partner for magnetic field coupling with the primary side 12. Then, the process proceeds to the next step S206.

  In step S206, the secondary controller 66 turns off the secondary switch 50 and then proceeds to the next step S207 and waits.

  On the other hand, in step S <b> 105, the primary side controller 26 keeps the primary side switch 18 in the ON state, and always energizes the primary side coil 20 from the AC power supply 16. As a result, the battery 34 can be in a state in which non-contact power feeding can be started from the primary coil 20 via the secondary coil 32, and the process proceeds to the next step S106. In FIG. 12, the time point t4 is in a state of step S105 on the primary side 12 and step S206 on the secondary side 14.

  In step S207, the secondary controller 66 determines whether or not the secondary side 14 is in a correct power receiving state when a sufficiently long time has elapsed since the secondary switch 50 was turned off in step S206. Determine.

  Specifically, the secondary-side controller 66 refers to the secondary-side data table 68, refers to the load resistance value Rz corresponding to the power reception current I2, and, on the other hand, based on the power reception voltage V2 and the power reception current I2. The received power P2 is calculated, the secondary data table 68 is referred to, the load resistance value Rz corresponding to the calculated received power P2 is referred, and it is determined whether or not each referenced load resistance value Rz is substantially equal. .

  If the determination result is affirmative in step S207 (step S207: YES), the process proceeds to the next step S208. In step S208, the secondary-side controller 66 sets the on-time Ton of the transistor 74 to the minimum unit time Δτ and supplies a control signal corresponding to the set minimum unit time Δτ to the base terminal of the transistor 74. The minimum energization control for conducting between the collector terminal 74 and the emitter terminal 74 is performed. Here, when the ON time Ton can be changed to n stages including 0, assuming that the PWM period for the transistor 74 is T, Δτ = T / (n−1).

  That is, the secondary-side controller 66 first sets the ON time Ton of the transistor 74 to the minimum unit time Δτ, and sets the ON time Ton from the minimum unit time Δτ to 2Δτ, 3Δτ,..., NΔτ. It is possible to perform energization control that is long. In this way, the secondary controller 66 changes the load resistance value Rz of the secondary side 14 from substantially infinite state toward 0 by changing the ON time Ton. Can be made.

  In FIG. 12, the time period from t4 to t5 is the state of step S207 on the secondary side 14, and the time point t5 is step S208.

  In the next step S209, the secondary controller 66 determines whether or not the secondary side 14 is in a correct power receiving state in the minimum energization control (turning on the transistor 74 at the minimum unit time Δτ). Similar determination processing is performed again. If the determination result is affirmative in step S209 (step S209: YES), the process proceeds to step S210 in FIG. In FIG. 12, the state after time t6 is the processing after step S210 on the secondary side 14.

  In addition, in each of the determination processes in steps S203, S205, S207, and S209 described above, if the determination result is negative (steps S203, S205, S207, and S209: NO), the secondary controller 66 is the secondary side. 14 determines that it is in an abnormal state that is not in a state where power can be received in a non-contact manner, and in the next step S211, the charging process on the secondary side 14 is terminated. That is, the transistor 74 and the DC / DC converter 62 are turned off.

  On the other hand, on the primary side 12, in step S106, the primary side controller 26 uses the primary side data table 28 to load based on the transmission current I1 when the transmission power P1 changes after step S105. When the resistance value Rz is referred to and, on the other hand, the load resistance value Rz based on the transmission power P1 is referred to and both the load resistance values Rz are substantially equal, the minimum energization control is performed on the secondary side 14. (Step S106: YES), the process proceeds to step S107 in FIG.

  In step S107, the primary controller 26 continues to check the state of the primary side 12. Specifically, by using the primary data table 28, the load resistance value Rz based on the transmission current I1 is referred to, while the load resistance value Rz based on the transmission power P1 is referred to and both load resistances are referred to. It is confirmed whether or not the values Rz are substantially equal, and whether or not a change such as an increase or decrease in the transmission power P1 is within a specified value (transmission power allowable range ΔP1NS) of the primary data table 28. . When it is a positive determination result in step S107 (step S107: YES), the process proceeds to the next step S108.

  In step S108, the primary controller 26 refers to the transmission power characteristic (transmission power P1) of the primary data table 28 and determines whether the control is performed by the NS circuit or the SS circuit. .

  When it is determined that the control is performed by the NS circuit (step S108: YES), the primary controller 26 sets the control flag SS indicating that the control by the SS circuit is being executed to 0 in step S109. In addition to setting, a control flag NS indicating that the control by the NS circuit is being executed is set to 1 (SS → 0, NS → 1). SS = 0 indicates that control by the SS circuit is not performed, and NS = 1 indicates that control by the NS circuit is performed.

  On the other hand, when it is determined that the control is performed by the SS circuit (step S108: NO), the primary controller 26 sets the control flag SS to 1 and sets the control flag NS to 0 in step S110. (SS → 1, NS → 0). SS = 1 indicates that control by the SS circuit is being performed, and NS = 0 indicates that control by the NS circuit is not being performed.

  In this operation description, since non-contact power supply is started from the control by the NS circuit, first, in step S109, the control flag is set to SS = 0 and NS = 1, and the process proceeds to the next step S111.

  In step S111, the primary-side controller 26 determines that the minimum elapsed time for the primary-side transmission power P1 on the primary side 12 is equal to or less than the specified time on the secondary-side 14 as well. It is determined whether or not it is less than the specified time. When it is a positive determination result in step S111 (step S111: YES), the process proceeds to the next step S112. That is, in the determination process of step S111, when the elapsed time in the minimum state exceeds the specified time, whether the secondary side 14 has ended abnormally or whether the secondary side 14 has ended normally due to the end of charging of the battery 34, Used to determine If the elapsed time in the minimum state is equal to or shorter than the specified time (step S111: YES), the process proceeds to step S112 to continue charging the battery 34.

  In step S112, the primary controller 26 has a control flag NS of 1, P1> P1old (P1NS> P1NSold) as compared with the received power P2old (P2NSold) calculated in the previous process, and It is compared with predetermined transmission power P1NSth to determine whether P1> P1NSth.

  Since non-contact power supply is started in the NS circuit, P1 <P1NSth in the initial stage of control by the NS circuit (step S112: NO), and the process proceeds to the next step S113.

  In step S113, the primary-side controller 26 determines whether or not the control flag SS is 1, P1 <P1old, and P1 <P1SSth.

  Since P1> P1old is satisfied at the initial stage of control by the NS circuit (step S113: NO), the primary-side controller 26 returns to step S107 and executes the processes of steps S107 to S113 again. As a result, the non-contact power feeding (charging the battery 34) from the primary side 12 to the secondary side 14 is continued with the control by the NS circuit.

  By continuously performing such processing, the transmission power P1 gradually increases due to the control on the received power P2 on the secondary side 14 as will be described later, and the transmission power in the vicinity of the maximum transmission power P1NSmax on the primary side 12 is increased. It approaches P1NSth. This initial state of control by the NS circuit corresponds to the time zone from time t11 to time t12 in FIG.

  In addition, when it is a negative determination result in steps S103, S106, and S107 (steps S103, S106, and S107: NO), the primary side controller 26 is not in a state where the primary side 12 is in a state where power can be transmitted. In step S120, the charging process on the primary side 12 is terminated.

  In this way, when the control by the NS circuit by the loop of steps S107 to S113 is performed on the primary side 12 and the charging of the battery 34 on the secondary side 14 is continued, the following control is performed on the secondary side 14: Execute.

  Since the secondary side 14 also starts from the control by the NS circuit, in step S210 in FIG. 10, the secondary side controller 66 sets the control flags SS and NS to SS → 0 and NS → 1, respectively.

  Next, in step S212, the secondary controller 66 performs the same determination process as in steps S207 and S209. This is because the initial loop process on the secondary side 14 described above is terminated, and then abnormality detection determination is performed in step S212 in the power tracking loop process repeatedly performed in step S212 and thereafter. If the determination result is affirmative in step S212 (step S212: YES), the process proceeds to the next step S213.

  In step S213, the secondary-side controller 66 compares the charging voltage V3 of the battery 34 with the end-of-charge voltage V3obj, compares the charging current I3 with the target charging current I3obj that can safely charge the battery 34, and V3 < It is determined whether V3obj and I3 <I3obj. When step S213 is an affirmative determination result (step S213: YES), the secondary-side controller 66 determines that both the charging current I3 and the charging voltage V3 are in a state in which the battery 34 can be safely charged. The process proceeds to S214.

  In step S214, the secondary controller 66 compares the received power P2 calculated in the current process with the received power P2old (P2Nold) calculated in the previous process, and determines whether P2> P2old. judge. When it is a positive determination result in step S214 (step S214: YES), the process proceeds to the next step S215. When P2> P2old, the state of the received power P2 is P2old toward the maximum received power P2max (P2NSmax) as shown in the time zone from time t11 to t12 in FIG. 5, FIG. 7, and FIG. Or a state in which the maximum received power P2NSmax has been reached once and then decreased and then increased toward the maximum received power P2NSmax.

  In step S215, the secondary-side controller 66 performs duty-up control (ON time) in order to decrease the load resistance value Rz and increase the received current I2 and the received power P2 in response to a power request from the battery 34 such as SOC. (Ton is incremented by Δτ from the previous time), and the process proceeds to the next step S216.

  In step S216, the secondary controller 66 compares the received power P2 with the received power P2NSth that is slightly smaller than the maximum received power P2NSmax. This is to determine whether or not switching from the control by the NS circuit to the control by the SS circuit is approaching.

  When P2 <P2NSth (step S216: YES), the secondary-side controller 66 determines that switching from the control by the NS circuit to the control by the SS circuit is not approaching, and the next step S217. Thus, the SS wait flag, which is a flag indicating a wait for switching from the control by the NS circuit to the control by the SS circuit, is set to 0.

  On the other hand, when P2 <P2NSth is not satisfied (step S216: NO), the secondary-side controller 66 determines that switching from the control by the NS circuit to the control by the SS circuit is approaching, and the next In step S218, the SS wait flag is set to 1.

  In step S219, the secondary-side controller 66 determines whether or not the elapsed time in the minimum state of the received power P2 (the time for which the state of P2≈0 continues) is equal to or shorter than the specified time. If the elapsed time in the minimum state is equal to or shorter than the specified time (step S219: YES), it is not possible to determine that the battery 34 has been fully charged, so the secondary controller 66 determines (P2 + ΔP2) in the next step S220. <P2old and whether the SS wait flag is 1 is determined. Step S220 determines whether or not the non-resonant circuit or the resonant circuit has been switched on the primary side 12. Here, ΔP2 is a predetermined reduction amount set in advance by the above-described experiment.

  As will be described later, the decrease amount ΔP2 is a threshold value for determining whether or not the received power P2 has changed by ΔP2 or more at the moment when the primary side 12 is switched from the non-resonant circuit to the resonant circuit. Accordingly, when switching occurs (step S220: YES), the secondary controller 66 switches to control by the SS circuit and sets the SS waiting flag to 0 in step S221.

  However, since the SS wait flag is not 1 at the initial stage of control by the NS circuit (SS wait flag: 0), a negative determination result is obtained in step S220 (step S220: NO). As a result, the secondary controller 66 returns to step S210 and repeats the processing of steps S210 to S220 until the primary side 12 switches from the control by the NS circuit to the control by the SS circuit, to the battery 34. Continue charging.

  On the other hand, a process when a negative determination result (steps S212 to S214: NO) in each determination process of steps S212 to S214 will be described below.

  If a negative determination result is obtained in step S212 (step S212: NO), the secondary controller 66 proceeds to step S211 and stops PWM control (sets the on time Ton of the transistor 74 to 0).

  When a negative determination result is obtained in step S213 (step S213: NO), the voltage V3 has reached the end-of-charge voltage V3obj, or the charging current I3 has reached the target charging current I3obj. become. In this case, the secondary controller 66 determines that the transistor 74 is turned on in step S222 so that the voltage V3 does not become higher than the end-of-charge voltage V3obj or the charging current I3 does not become larger than the target charging current I3obj. Ton is decremented by Δτ from the previous time. Thereafter, the process proceeds to next Step S216.

  If a negative determination result is obtained in step S214 (step S214: NO), the process proceeds to the next S222. The state resulting in such a determination is a region on the left side of the maximum received power P2max (region where the load resistance value Rz is low) in FIG. 7, and the received power P2 is equal to or lower than the previous value.

  In this case, in step S222, the secondary controller 66 decrements the ON time Ton of the transistor 74 by Δτ from the previous time so that the received power P2 approaches the maximum received power P2max, and proceeds to step S216.

  In this manner, by repeatedly performing the processes of steps S212 to S220 and S222, that is, in response to the power request from the battery 34, the process of incrementing or decrementing the on-time Ton of the transistor 74 by Δτ from the previous time is repeated. Thus, the received power P2 is controlled so as to gradually approach the maximum received power P2max while gradually increasing the duty of the on-time Ton from the time t11 to the time t12. With such control, in the time period from t11 to t12, as the time elapses, charging of the battery 34 proceeds, and the SOC and the charging voltage V3 gradually increase.

  As a result, also on the primary side 12, the transmission power P1 gradually increases. Thereafter, when the transmitted power P1 exceeds the transmitted power P1NSth (step S112 in FIG. 9: YES), the process proceeds to the next step S114. In step S114, the primary controller 26 sets the control flag SS to 1 and sets the control flag NS to 0. In the next step S115, the primary side controller 26 controls the changeover switch 15 to switch the primary side resonance capacitor 21 to the connected state. Thereby, the primary side coil 20 and the primary side resonance capacitor 21 are connected in series, and the control by the NS circuit is switched to the control by the SS circuit. As a result, on the primary side 12, the processing of steps S107 to S113 is continued by the SS circuit.

  Such control switching on the primary side 12 can be grasped by capturing a change in the received power P2 on the secondary side.

  That is, when the transmitted power P1 exceeds the transmitted power P1NSth, the secondary controller 66 refers to the secondary data table 68 and the received power P2 exceeds the received power P2NSth near the maximum received power P2NSmax (step S216). : NO), the process proceeds to the next step S218. In step S218, the secondary controller 66 sets the SS wait flag to 1. Therefore, the secondary controller 66 continues the control by the NS circuit while grasping that the primary side 12 will soon be switched from the control by the NS circuit to the control by the SS circuit.

  Even when the primary side 12 is switched to the control by the SS circuit, the secondary side 14 continues the on / off control of the transistor 74 by the PWM control. In this case, at the moment when the primary side resonance capacitor 21 is connected in series with the primary side coil 20 and the primary side 12 becomes a resonance circuit (time t12 in FIG. 13 when the circuit is switched to the SS circuit), the transmission power P1 In addition, the received power P2 has a power value that is reduced by a predetermined decrease amount ΔP2 or more than when the control is performed by the NS circuit.

  In FIGS. 5 and 7, the amount of decrease ΔP <b> 2 of the power value that accompanies the switching is illustrated by a downward arrow from P <b> 2 NS to P <b> 2 SS. 4 and 6, a downward arrow from P1NS to P1SS indicates a power value decrease amount on the primary side 12 according to the power value decrease amount ΔP2 on the secondary side 14.

  Therefore, when the secondary controller 66 detects that the power value has decreased by a predetermined decrease amount ΔP2 or more with the SS waiting flag set to 1 (step S220: YES), the primary side 12 is controlled by the resonance circuit. The SS wait flag is set to 0 in the next step S221. Thereby, the secondary side 14 shifts to a control flow by the SS circuit shown in FIG.

  That is, in step S223 in FIG. 11, the secondary controller 66 sets the control flag SS to 1 and the control flag NS to 0. In addition, with the switching to the SS circuit, the primary side controller 26 and the secondary side controller 66 are respectively provided with the SS circuit data table (the word “SS” in FIGS. 6 and 7). Of course, the characteristic) is referred to.

  Next, in step S224, the secondary-side controller 66 performs the same determination process as in steps S207, S209, and S212. This is for ending the initial loop on the secondary side 14 and determining abnormality detection in the power tracking loop repeated after step S224. In addition, when abnormality is detected by step S224 (step S224: NO), it returns to step S211 and complete | finishes a charging process.

  If the determination result is affirmative in step S224 (step S224: YES), the process proceeds to the next step S225. In step S225, the secondary-side controller 66 determines whether or not V3 <V3obj, I3 <I3obj, and P2 <P2SSmax (P2SSmax: maximum received power in the SS circuit).

  If the determination result in step S225 is affirmative (step S225: YES), both the charging current I3 and the charging voltage V3 are in a state in which the battery 34 can be safely charged, and the received power P2 (P2SS) is the maximum received power. Since it is smaller than P2SSmax, the secondary-side controller 66 proceeds to the next step S226.

  In step S226, the secondary controller 66 compares the received power P2 with the previous received power P2old (P2SSold). When P2> P2old (step S226: YES), the received power P2 is monotonically increasing from P2old toward the maximum received power P2SSmax as in the time period from time t12 to time t13 in FIG. Therefore, the secondary controller 66 proceeds to the next step S227 in order to continue charging the battery 34.

  In step S227, the secondary-side controller 66 performs duty-down control, that is, control to decrement the ON time Ton of the transistor 74 by Δτ from the previous time in order to increase the received power P2, and proceeds to the next S228. Thus, in the control by the SS circuit, unlike the control by the NS circuit, the on-time Ton is shortened in the time zone from the time t12 to the time t13 in FIG. 13 in order to increase the received power P2. Control.

  When a negative determination result is obtained in step S225 (step S225: NO), the secondary-side controller 66 proceeds to the next step S229 to reduce the charging voltage V3, the charging current I3, or the received power P2. The ON time Ton of the transistor 74 is incremented by Δτ from the previous time. Further, when a negative determination result is obtained in step S226 (step S226: NO), the secondary controller 66 increments the on-time Ton by Δτ from the previous time in order to decrease the received power P2 in step S229. .

  In step S228, the secondary-side controller 66 compares the received power P2 with the received power P2SSth that is the minimum value of the received power P2 under the control of the SS circuit. This is to determine whether or not switching from the control by the SS circuit to the control by the NS circuit is approaching.

  When P2> P2SSth (step S228: YES), the secondary-side controller 66 determines that switching from the control by the SS circuit to the control by the NS circuit is not approaching, and in the next step S230, the S The NS wait flag, which is a flag for waiting for switching from the control by the -S circuit to the control by the NS circuit, is set to 0.

  On the other hand, when the determination result is negative in step S228 (step S228: NO), the secondary controller 66 determines that the switching from the control by the SS circuit to the control by the NS circuit is approaching. In the next step S231, the NS waiting flag is set to 1.

  In the next step S232, the secondary controller 66 determines whether (P2 + ΔP2)> P2old and whether the NS wait flag is 1. Step S232 determines whether or not the primary side 12 has been switched from the resonant circuit to the non-resonant circuit.

  In this case, it is the initial stage when switching to the control by the SS circuit, and the NS waiting flag is not 1 (step S232: NO). Therefore, the secondary-side controller 66 returns to step S224 until the primary side 12 switches from control by the SS circuit to control by the NS circuit (until step S232 becomes a positive determination result). The control loop process of S224 to S232 is repeated, and the charging of the battery 34 is continued.

  Thereafter, when the received power P2 continues to increase and reaches the maximum received power P2SSmax under the control of the SS circuit (step S225: NO, time t14 in FIG. 13), the power that is equal to or greater than the maximum received power P2SSmax is acquired. I can't. Therefore, the secondary controller 66 performs feedback control on the received power P2 in the vicinity of the maximum received power P2SSmax while increasing / decreasing the ON time Ton of the transistor 74 by PWM control (step S227 or S229). That is, the secondary-side controller 66 waits for the SOC of the battery 34 to rise with time by performing feedback control. When the SOC increases, the charging current I3 reaches the target charging current I3obj, or the charging voltage V3 reaches the charging end voltage V3obj (step S225: NO, time point t16 in FIG. 13), the secondary side controller 66 increases the on-time Ton by PWM control in order to reduce the power supply to the battery 34 (step S229).

  When the battery 34 approaches full charge and the power demand from the battery 34 decreases (time zone after time t16 in FIG. 13), the received power P2 approaches the received power P2SSth. It can be grasped that the primary side 12 will soon be switched to the control by the NS circuit (step S228: NO → step S231).

  On the other hand, the transmitted power P1 on the primary side 12 and the received power P2 on the secondary side 14 change with each other in response to a power request from the battery 34. Therefore, the primary side controller 26 can grasp | ascertain the fall of an electric power request | requirement by monitoring the fall of the transmission power P1.

  Then, when the transmission power P1 decreases and falls below the transmission power P1SSth (step S113: YES), the primary controller 26 proceeds to the next step S116. In step S116, the primary side controller 26 sets the control flag SS to 0, sets the control flag NS to 1, controls the changeover switch 15, and switches the primary side resonance capacitor 21 to the bypass state. Thereby, in step S117, the primary side 12 is switched from the resonant circuit (SS circuit) to the non-resonant circuit (SS circuit) (time t18 in FIG. 13). Thereafter, on the primary side 12, the control loop processing from step S107 is performed under the control of the NS circuit.

  On the other hand, on the secondary side 14, the control of the on-time Ton for the transistor 74 is continued by PWM control even at the moment when the control switching to the NS circuit is performed on the primary side 12. Before this moment, the received power P2 has dropped below P2SSth (step S228: NO), and the NS waiting flag is set to 1 in the next step S231. As a result, in step S232, when the secondary controller 66 detects a decrease in the power value equal to or greater than the decrease amount ΔP2 of the received power P2 (step S232: YES), the primary side 12 is controlled by the NS circuit. It is understood that it has returned, and the NS wait flag is set to 0 in the next step S233. Thereby, at the secondary side 14, it returns to step S210 and transfers to control by a NS circuit.

  On the secondary side 14, when the control is shifted to the NS circuit, the duty is increased until the charging current I3 reaches the target charging current I3obj in the time period t18 to t19 in order to compensate for the power decrease of the decrease amount ΔP2. The control is repeated (steps S212 to S214: YES → step S215). Thereafter, when the charging current I3 reaches the vicinity of the target charging current I3obj at time t19, the duty up control and the duty down control are alternately performed in the time period from t19 to t20, and the charging current I3 is changed to the target charging current I3obj. While maintaining the control, the control by the NS circuit is continued so that the received power P2 slightly increases as the charging voltage V3 slightly increases.

  In the next time period from t20 to t21, as the target charging current I3obj decreases, the charging current is controlled so as to follow the decrease in the target charging current I3obj by performing duty down control while continuing the control by the NS circuit. Reduce I3. Thereby, the received power P2 also decreases. Thereafter, in the time period from t21 to t22, the duty-up control and the duty-down control are alternately performed, and while maintaining the charging current I3 at the target charging current I3obj after the decrease, with a slight increase in the charging voltage V3, The control by the NS circuit is continued so that the received power P2 slightly increases.

  Thereafter, at time t22 in FIG. 13, when the SOC increases to 100%, the charge voltage V3 reaches the charge end voltage V3obj, and the process proceeds from step S213 to step S222, the on-time Ton becomes 0 or near zero. The charging to the battery 34 is stopped or the power supply state is minimum.

  By continuing the state where the on-time Ton is close to 0, the received power P2 is reduced, and as a result, the transmitted power P1 is also reduced. Therefore, when the minimum power supply state continues continuously for the specified time (step S111: NO), the primary side controller 26 turns off the primary side switch 18 in step S119, Charging control is completed (time t23 in FIG. 13). On the other hand, in the secondary side controller 66 as well, when the minimum power supply state continues continuously for a specified time (step S219: NO), the charging control for the battery 34 is terminated in step S234 ( Time t24 in FIG. 13).

[Description of modification]
In the power supply system 10, the case where the contactless power feeding is performed from the primary side 12 to the secondary side 14 by switching to the NS circuit or the SS circuit has been described. When within the range of power P1, the primary side controller 26 maintains the changeover switch 15 in the bypass state of the primary side resonance capacitor 21, and maintains the circuit on the primary side 12 as a non-resonant circuit. -You may perform non-contact electric power feeding by S circuit.

  The power supply system 10 may be configured as shown in FIG. In FIG. 14, a series circuit of a resistor 92 and a short-circuiting switch 90 that is turned on / off under the control of the primary-side controller 26 is connected in parallel to the primary-side resonant capacitor 21. As a result, when switching to the resonance circuit or the non-resonance circuit by the changeover switch 15, when the shorting switch 90 is turned on, the charge accumulated in the primary resonance capacitor 21 is quickly discharged by the resistor 92.

[Effect of this embodiment]
As described above, according to the power supply system 10 according to the present embodiment, without exchanging information such as power supply information between the primary side 12 on the power supply side and the secondary side 14 on the power reception side, Further, contactless power supply from the primary side 12 to the secondary side 14 can be performed at a low cost without using an inverter on the primary side 12. That is, the circuit on the primary side 12 that supplies power without contact is switched to a resonance circuit or a non-resonance circuit with a simple configuration using the changeover switch 15, thereby responding to a power request from the secondary side 14. Thus, non-contact power supply can be appropriately performed.

  Since the primary side 12 does not use an inverter, the frequency and voltage of a base power source such as an AC power source attached to the infrastructure on which the primary side 12 is installed can be used as it is to supply power to an electric vehicle or the like. Non-contact power feeding can be performed. Specifically, when power is supplied to a power supply object using general infrastructure, the frequency of the commercial power supply (commercial frequency) can be used as it is. In addition, when power is supplied to a power supply target in a ship or an aircraft, the infrastructure frequency in the ship and the aircraft can be used as it is. For example, in an aircraft, a frequency of 400 Hz that is an infrastructure frequency in the aircraft can be used as it is.

  Here, since the primary side 12 includes the AC power source 16, the primary side switch 18, the changeover switch 15, and the primary side controller 26, power is efficiently supplied from the AC power source 16 to the resonance circuit or the non-resonance circuit. be able to.

  Further, by switching power to the non-resonant circuit from the AC power source 16 while switching to the non-resonant circuit by the changeover switch 15 and conducting the AC power source 16 and the non-resonant circuit by the primary side switch 18, Contactless power supply from the primary side 12 to the secondary side 14 is started. Thereby, contactless power supply can be performed while avoiding a large current exceeding the allowable current value flowing through the primary side 12 and the secondary side 14 at the start of the contactless power supply.

  Further, the non-resonant circuit and the resonant circuit include the primary side coil 20, the secondary side 14 includes the secondary side coil 32 and the battery 34, and magnetic field coupling between the primary side coil 20 and the secondary side coil 32 Since non-contact power supply from the primary side 12 to the secondary side 14 is performed, non-contact power supply can be performed efficiently.

  Further, since the secondary side 14 is a resonance circuit including the secondary side coil 32, when the non-contact power supply is started, the power supply is started by the NS circuit, and then the power demand of the secondary side 14 is met. Accordingly, it is possible to switch to the SS circuit and perform power supply. That is, first, the NS circuit starts supplying power safely in a low power state while avoiding a large current exceeding the allowable current value, and then according to the power requirement of the secondary side 14, The selector switch 15 can be used to switch to the SS circuit to supply a large amount of power.

  In this case, the secondary-side controller 66 on the secondary side 14 controls the load resistance value Rz in response to the power request from the battery 34, and the primary-side controller 26 transmits power for performing non-contact power supply. Based on the power P1, the selector switch 15 is controlled to switch to a non-resonant circuit or a resonant circuit. Thus, by providing a controller on each of the primary side 12 and the secondary side 14, the primary side 12 knows the status of the secondary side 14 without exchanging information such as power supply information. Instead, it can be determined whether or not to switch to a non-resonant circuit or a resonant circuit based on the transmission power P1 to be monitored. As a result, the non-contact power supply can be easily and appropriately controlled.

  Specifically, when the contactless power supply is started in a state where the primary side 12 is switched to the non-resonant circuit, when the transmission power P1 reaches a predetermined transmission power P1NSth, the primary controller 26 The changeover switch 15 is controlled to switch from the non-resonant circuit to the resonant circuit.

  That is, after switching from the non-resonance circuit to the resonance circuit by the changeover switch 15, the secondary-side controller 66 controls the load resistance value Rz to increase, thereby receiving the received power P <b> 2 received on the secondary side 14. Increase.

  The primary-side controller 26 controls the changeover switch 15 when the received power P2 is such that the received power P2 decreases by a predetermined decrease amount ΔP2 before and after switching from the non-resonant circuit to the resonant circuit. Thus, the non-resonant circuit is switched to the resonant circuit.

  As a result, the secondary controller 66 determines that the circuit on the primary side 12 has been switched from the non-resonant circuit to the resonant circuit by detecting a decrease in the amount of decrease ΔP2 in the received power P2, and performs desired control. It becomes possible. In addition, since the switching point is set so that the received power P2 decreases by the decrease amount ΔP2 or more when switching from the non-resonant circuit to the resonant circuit, the charging voltage V3 and the charging current I3 on the battery 34 side before and after the switching are It is possible to avoid exceeding allowable values (end-of-charge voltage V3obj, target charging current I3obj).

  In addition, after switching from the non-resonant circuit to the resonant circuit, when the secondary controller 66 is controlled to decrease the load resistance value Rz with a decrease in power requirement, the primary controller 26 Before and after switching from the circuit to the non-resonant circuit, the switch 15 is controlled to switch from the resonant circuit to the non-resonant circuit when the received power P2 is the transmission power P1 such that the received power P2 decreases by a predetermined decrease ΔP2 or more. .

  Even in this case, the secondary-side controller 66 determines that the circuit on the primary side 12 has been switched from the resonant circuit to the non-resonant circuit by detecting a decrease in the received power P2 by a predetermined decrease amount ΔP2 or more. Control can be performed. In addition, since the switching point is set so that the received power P2 decreases by the decrease amount ΔP2 or more when switching from the resonance circuit to the non-resonance circuit, the charging voltage V3 and the charging current I3 before and after switching are changed to the charging end voltage V3obj And exceeding the target charging current I3obj can be avoided.

  In the power supply system 10, the power supplied to the battery 34 can be increased smoothly by starting from the power supply by the NS circuit and then switching to the power supply by the SS circuit. Further, just before the power supply to the battery 34 is finished, in order to reduce the power supplied to the battery 34, the power transmission current I1 is not increased by returning from the SS circuit to the NS circuit. Electric power can be supplied in a low power state. As a result, the non-contact power supply can be easily and appropriately controlled from the start to the end of the non-contact power supply to the battery 34.

  In the power supply system 10, it is also possible to supply power without contact without switching between the NS circuit and the SS circuit. When the power request from the battery 34 is within the range of the transmission power P1 by the non-resonant circuit, the circuit on the primary side 12 is maintained in the non-resonant circuit without switching by the changeover switch 15. Even in this case, the contactless power supply can be easily and appropriately controlled from the start to the end of the contactless power supply to the battery 34.

  Further, the secondary-side controller 66 determines that the non-resonant circuit or the resonant circuit has been switched by the changeover switch 15 when the received power P2 has decreased by a decrease amount ΔP2 or more, and based on the determination result. Since the non-contact power supply is controlled, the secondary side 14 can easily determine the switching of the non-resonant circuit or the resonant circuit.

  Further, since the changeover switch 15 switches the primary side resonance capacitor 21 to the bypass state or the connection state by the control from the primary side controller 26, the primary side 12 is switched to the non-resonance circuit or the resonance circuit with a simple configuration. be able to.

  Furthermore, a series circuit of a short circuit switch 90 and a resistor 92 that are turned on and off by the control from the primary side controller 26 and the resistor 92 are connected in parallel to the primary side resonance capacitor 21, so that the resonance circuit is switched to the non-resonance circuit. When switching to, by turning on the short-circuiting switch 90, the charge accumulated in the primary side resonance capacitor 21 can be quickly discharged by the resistor 92. As a result, when the non-resonant circuit or the resonance circuit is switched by the changeover switch 15, it is possible to avoid the occurrence of welding of the contact of the changeover switch 15 due to the generation of an arc due to the charge accumulated in the primary side resonance capacitor 21. it can.

  In addition, a series circuit of the secondary side switch 50 and a resistor 52 having a resistance value set to an arbitrary fixed value within a possible range of the load resistance value Rz is connected to the secondary side coil 32, The secondary side controller 66 controls conduction between the secondary side coil 32 and the resistor 52 by turning on and off the secondary side switch 50. As described above, by using the resistor 52 having a resistance value set to an arbitrary fixed value within a range that the load resistance value Rz can take, it is accurately determined whether or not non-contact power supply is possible. be able to.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the contents described in this specification.

DESCRIPTION OF SYMBOLS 10 ... Electric power supply system 12 ... Primary side 14 ... Secondary side 15 ... Changeover switch (switching means)

Claims (16)

In a power supply system that supplies power from the primary side to the secondary side in a contactless manner,
Switching means provided on the primary side and capable of switching the primary side circuit for supplying electric power from the primary side to the secondary side in a non-contact manner to a resonant circuit or a non-resonant circuit. And power supply system. The power supply system according to claim 1, wherein
The primary side includes a power source that supplies power to the resonant circuit or the non-resonant circuit, a primary side switch that electrically connects the power source to the resonant circuit or the non-resonant circuit after switching, and the switching unit. And a primary side control means for controlling switching by the switching means and on / off of the primary side switch. The power supply system according to claim 2,
By switching the non-resonant circuit by the switching means and supplying the power from the power source to the non-resonant circuit in a state where the power source and the non-resonant circuit are conducted by the primary side switch, A power supply system, wherein non-contact power supply from the primary side to the secondary side is started. The power supply system according to claim 3, wherein
The non-resonant circuit and the resonant circuit include a primary coil,
The secondary side includes a secondary coil disposed with a gap from the primary coil, and a load connected to the secondary coil,
A non-contact power supply from the primary side to the secondary side is performed by magnetic field coupling between the primary side coil and the secondary side coil. The power supply system according to claim 4, wherein
The power supply system, wherein the secondary side has a resonance circuit including the secondary side coil. The power supply system according to claim 5, wherein
A secondary that controls non-contact power supply from the primary coil to the load via the secondary coil by controlling a load resistance value when the load is viewed from the secondary coil. Side control means,
The primary-side control means controls the switching means based on the primary-side transmitted power for performing the non-contact power supply, and switches to the non-resonant circuit or the resonant circuit. Power supply system. The power supply system according to claim 6, wherein
When the non-contact power supply is started in a state where the primary side is switched to the non-resonant circuit, the primary side control unit is configured to switch the switching unit when the transmitted power reaches a predetermined power value. And switching from the non-resonant circuit to the resonant circuit. The power supply system according to claim 7, wherein
After switching from the non-resonant circuit to the resonant circuit by the switching unit, the secondary side control unit performs control so as to increase the load resistance value, thereby receiving power received on the secondary side. A power supply system characterized by increasing the power. The power supply system according to claim 8, wherein
The primary control means switches from the non-resonant circuit to the resonant circuit when the transmitted power is such that the received power decreases by a predetermined amount before and after switching from the non-resonant circuit to the resonant circuit. Power supply system characterized by The power supply system according to claim 9, wherein
After the switching from the non-resonant circuit to the resonant circuit, the secondary side control means controls the primary resistance when the load resistance value is controlled to decrease as the power demand from the load decreases. The side control means controls the switching means when the transmission power is such that the received power is reduced by the predetermined amount before and after switching from the resonance circuit to the non-resonance circuit. A power supply system that switches to the non-resonant circuit. The power supply system according to claim 10, wherein
The secondary side control means includes:
Starting from an initial state in which the load resistance value becomes substantially infinite in response to an increase in the power requirement in a state where the non-resonant circuit is switched, the load resistance value decreases with time. By controlling the non-contact power supply,
After switching from the non-resonant circuit to the resonant circuit, the non-contact power supply is controlled by controlling the load resistance value to increase with time in response to an increase in the power demand. And
Then, in response to the decrease in power demand, the non-contact power supply is controlled so that the load resistance value decreases with time,
Furthermore, after switching from the resonant circuit to the non-resonant circuit, the non-contact power supply is controlled by controlling the load resistance value to increase with time. system. The power supply system according to claim 10, wherein
When the transmitted power is within the control range of the transmitted power by the non-resonant circuit, the primary-side control unit switches the primary-side circuit to the non-resonant circuit without switching by the switching unit. Maintain,
The secondary side control means includes:
Corresponding to the increase in power demand, the non-contact power supply is controlled so that the load resistance value decreases as time elapses, starting from an initial state where the load resistance value becomes substantially infinite. ,
Thereafter, the non-contact power supply is controlled so that the load resistance value increases with time with respect to a decrease in the power demand. The power supply system according to any one of claims 10 to 12,
The secondary-side control means determines that the switching of the non-resonant circuit or the resonant circuit is performed by the switching means when the predetermined amount of the received power is reduced, and based on the determination result A power supply system for controlling the non-contact power supply. The power supply system according to any one of claims 4 to 13,
The primary side resonance circuit includes the primary side coil and a primary side capacitor,
The switching means is a change-over switch that switches connection between the primary side switch and the primary side capacitor or bypass of the primary side capacitor under the control of the primary side control means. Power supply system. The power supply system according to claim 14, wherein
A power supply system, wherein a series circuit of a short-circuiting switch that is turned on and off by control from the primary-side control means and a resistor is connected to both ends of the primary-side capacitor. The power supply system according to any one of claims 6 to 15,
A series circuit of a secondary side switch and a resistor having a resistance value set to an arbitrary fixed value within a range that the load resistance value can take is connected to the secondary side coil,
The said secondary side control means controls conduction | electrical_connection with the said secondary side coil and the said resistor by turning on and off the said secondary side switch, The electric power supply system characterized by the above-mentioned.

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