WO2014103280A1 - Non-contact power supply apparatus - Google Patents

Non-contact power supply apparatus Download PDF

Info

Publication number
WO2014103280A1
WO2014103280A1 PCT/JP2013/007533 JP2013007533W WO2014103280A1 WO 2014103280 A1 WO2014103280 A1 WO 2014103280A1 JP 2013007533 W JP2013007533 W JP 2013007533W WO 2014103280 A1 WO2014103280 A1 WO 2014103280A1
Authority
WO
WIPO (PCT)
Prior art keywords
secondary battery
circuit
voltage
power
primary
Prior art date
Application number
PCT/JP2013/007533
Other languages
French (fr)
Japanese (ja)
Inventor
岩宮　裕樹
シュテフェン ヴェルナー
Original Assignee
パナソニック株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by パナソニック株式会社 filed Critical パナソニック株式会社
Publication of WO2014103280A1 publication Critical patent/WO2014103280A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/80—Circuit arrangements or systems for wireless supply or distribution of electric power involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
    • H02J50/12—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling of the resonant type

Definitions

  • the present invention relates to a non-contact power feeding device that transmits power in a non-contact manner.
  • FIG. 3 shows a configuration of a conventional power supply apparatus.
  • the power supply side circuit 101 includes an AC power supply unit 103, a DC power supply unit 105, a voltage type inverter 107, a power supply coil 111, and a primary capacitor 113.
  • the DC power supply unit 105 converts the AC voltage supplied from the AC power supply unit 103 into a DC voltage.
  • the voltage type inverter 107 reversely converts the DC voltage output from the DC power supply unit 105 into high frequency power.
  • the voltage type inverter 107 includes four switches S 1 to S 4 .
  • the feeding coil 111 supplies the high frequency power output from the voltage type inverter 107 to the power receiving side circuit 109 in a non-contact manner.
  • the primary capacitor 113 is connected in series with the feeding coil 111.
  • the power receiving side circuit 109 includes a power receiving coil 115, a short-circuit switch S 5, a rectifier 119, a smoothing capacitor 121, and a load 123 such as a battery.
  • the power receiving coil 115 receives high frequency power from the power feeding coil 111.
  • Shunt switch S 5 is connected in parallel to the power receiving coil 115.
  • the rectifier 119 rectifies the high frequency power received by the power receiving coil 115.
  • the smoothing capacitor 121 smoothes the output voltage of the rectifier 119.
  • the power conversion control unit 125 Based on the load constant current / constant voltage (CC / CV) command from the load control unit 127, the power conversion control unit 125 switches control as follows. First, depending on the state of the load 123 by controlling the ON / OFF switching of the shorting switch S 5, it switches the constant current control and constant voltage control. Next, ON / OFF of the switches S 1 to S 4 constituting the voltage type inverter 107 of the power supply side circuit 101 is controlled, and constant current control and constant control of the output of the voltage type inverter 107 are performed by control by a pulse width modulation (PWM) method. Switch voltage control. Therefore, the power conversion control unit 125 can switch the four control patterns.
  • PWM pulse width modulation
  • the contactless power supply device of the present invention includes a power transmission circuit, a primary resonance circuit, a secondary resonance circuit, a rectifier circuit, and a secondary battery.
  • the primary resonant circuit includes a primary coil and is electrically connected to the power transmission circuit.
  • the secondary resonance circuit includes a secondary coil that receives power in a non-contact manner when facing the primary coil.
  • the rectifier circuit is electrically connected to the secondary resonant circuit.
  • the secondary battery is electrically connected to the rectifier circuit.
  • the secondary battery has an output impedance Zout.
  • the secondary battery has a secondary battery impedance ZL.
  • the output impedance Zout is set in advance so that the ratio ZL / Zout of these impedances is substantially equal to the step-up ratio Du or step-down ratio Dd of the rectifier circuit.
  • the secondary battery impedance ZL increases as the charging of the secondary battery proceeds.
  • the output impedance Zout of the secondary resonance circuit also increases.
  • the output impedance Zout is adjusted so that the above-described ratio (ZL / Zout) is substantially equal to the step-up ratio Du or step-down ratio Dd of the rectifier circuit. Therefore, the output impedance Zout also increases at the same rate as the rate at which the secondary battery impedance ZL increases when the secondary battery is charged.
  • the secondary battery voltage Vb is determined based on the output impedance Zout and the step-up ratio Du or step-down ratio Dd (both are constant values) of the rectifier circuit.
  • the secondary battery voltage Vb increases at the same rate as the secondary battery impedance ZL increases. Since the charging current Ib to the secondary battery is determined by dividing the secondary battery voltage Vb by the secondary battery impedance ZL, when the secondary battery voltage Vb and the secondary battery impedance ZL increase at the same ratio, the charging current Ib is It becomes constant.
  • the non-contact power feeding device can charge the secondary battery with a constant current with a simple configuration without a special constant current circuit.
  • Block circuit diagram of the non-contact power feeding device in Embodiment 1 of the present invention Block circuit diagram of a non-contact power feeding device in Embodiment 2 of the present invention The figure which shows the structure of the electric power feeder of the conventional electric power feeder
  • the load 123 can be charged with constant current / constant voltage by switching four control patterns.
  • the configuration and control of the power conversion control unit 125 are complicated for that purpose.
  • the power conversion control unit 125 needs to control the switches S 1 to S 4 in the power supply side circuit 101 and the short-circuit switch S 5 in the power reception side circuit 109, and monitor the voltages of the power reception coil 115 and the load 123.
  • the power conversion control unit 125 needs to be involved in both the power feeding side circuit 101 and the power receiving side circuit 109, and is complicated as a non-contact power feeding device.
  • FIG. 1 is a block circuit diagram of a non-contact power supply apparatus 11A according to Embodiment 1 of the present invention.
  • the contactless power supply device 11 ⁇ / b> A includes a power transmission circuit 13, a primary resonance circuit 15, a secondary resonance circuit 17, a rectifier circuit 19, and a secondary battery 21.
  • the primary resonance circuit 15 includes a primary coil and is electrically connected to the power transmission circuit 13.
  • the secondary resonant circuit 17 includes a secondary coil 37 that receives power in a non-contact manner when facing the primary coil 23.
  • the rectifier circuit 19 is electrically connected to the secondary resonance circuit 17.
  • the secondary battery 21 is electrically connected to the rectifier circuit 19.
  • the power transmission circuit 13 and the primary resonance circuit 15 constitute a power supply unit, and the secondary resonance circuit 17, the rectifier circuit 19, and the secondary battery 21 constitute a power reception unit.
  • the secondary resonance circuit 17 When the primary coil 23 and the secondary coil 37 are opposed to each other, the secondary resonance circuit 17 has an output impedance Zout.
  • the secondary battery 21 has a secondary battery impedance ZL.
  • the output impedance Zout is set in advance so that the ratio ZL / Zout of these impedances is substantially equal to the step-up ratio Du or the step-down ratio Dd of the rectifier circuit 19.
  • the secondary battery impedance ZL increases.
  • the output impedance Zout of the secondary resonance circuit 17 also increases correspondingly.
  • the output impedance Zout is adjusted so that the ratio ZL / Zout is substantially equal to the step-up ratio Du or the step-down ratio Dd of the rectifier circuit 19. Therefore, the output impedance Zout also increases at the same rate as the secondary battery impedance ZL increases when the secondary battery 21 is charged.
  • the secondary battery voltage Vb is determined based on the output impedance Zout and the step-up ratio Du or step-down ratio Dd (both are constant values) of the rectifier circuit 19. Therefore, the secondary battery voltage Vb rises at the same rate as the rate at which the secondary battery impedance ZL rises. Therefore, the charging current Ib to the secondary battery 21 is determined by dividing the secondary battery voltage Vb by the secondary battery impedance ZL. Thus, when the secondary battery voltage Vb and the secondary battery impedance ZL increase at the same ratio, the charging current Ib becomes constant. Therefore, the non-contact power feeding apparatus 11A can charge the secondary battery 21 with a constant current with a simple configuration without a special constant current circuit.
  • the power transmission circuit 13 converts, for example, power from a commercial system power supply (not shown) into AC power having a frequency f necessary for non-contact power feeding. Therefore, non-contact power feeding is started when the power transmission circuit 13 operates.
  • a primary resonance circuit 15 is electrically connected to the power transmission circuit 13.
  • the primary resonance circuit 15 is provided to transmit power from the power transmission circuit 13 to the secondary resonance circuit 17.
  • the primary resonant circuit 15 has a configuration in which a primary coil 23 and a primary capacitor 25 for configuring the resonant circuit are electrically connected in series.
  • the primary resonance circuit 15 includes a primary internal resistance 27 in the primary coil 23.
  • the primary coil 23 includes a series circuit including a power transmission coil portion 29 that contributes to actual power transmission and a non-power transmission coil portion 31 other than that. Therefore, the primary resonance circuit 15 is configured by a series circuit of the primary capacitor 25, the primary internal resistance 27, and the primary coil 23.
  • the configuration of the secondary resonance circuit 17 is the same as the configuration of the primary resonance circuit 15. That is, the secondary resonance circuit 17 is configured by a series circuit of a secondary capacitor 33, a secondary internal resistor 35, and a secondary coil 37.
  • the secondary coil 37 can be arranged to face the primary coil 23. When the secondary coil 37 faces the primary coil 23, the power transmitted from the primary coil 23 is received by the secondary coil 37 in a non-contact manner.
  • the secondary coil 37 is configured by a series circuit of a power receiving coil portion 39 that contributes to actual power reception and other non-power receiving coil portions 41 in terms of an equivalent circuit.
  • a rectifier circuit 19 is electrically connected to the secondary resonance circuit 17.
  • the rectifier circuit 19 converts AC power received by the secondary resonance circuit 17 into DC power.
  • the rectifier circuit 19 has a configuration in which four diodes 43 are connected in a bridge shape.
  • the ratio of the input voltage to the output voltage is referred to as a boost ratio Du.
  • the rectifier circuit 19 since the rectifier circuit 19 is configured to step up, the following description will be made using the step-up ratio Du.
  • the configuration in which the rectifier circuit 19 steps down has a step-down ratio Dd.
  • the “step-up ratio Du” may be read as “step-down ratio Dd” in the following description.
  • a secondary battery 21 is electrically connected to the rectifier circuit 19. Therefore, the power output from the power transmission circuit 13 is charged in the secondary battery 21 in a non-contact manner.
  • a lithium ion battery is used as the secondary battery 21.
  • only the secondary battery 21 is configured as a charger connected to the rectifier circuit 19, but a load (not shown) to which power is supplied from the secondary battery 21 is connected. May be.
  • the secondary battery impedance ZL can be obtained using the equation (1) when the secondary battery 21 is charged with the constant charging current Ib.
  • the secondary battery impedance ZL of the secondary battery 21 to be used is obtained in advance using the equation (1).
  • the boost ratio Du of the rectifier circuit 19 is obtained.
  • the step-up ratio Du is uniquely determined by the diode 43 used.
  • the output impedance Zout in the secondary resonance circuit 17 is determined from the secondary battery impedance ZL thus obtained and the step-up ratio Du. As described above, the ratio ZL / Zout of the secondary battery impedance ZL to the output impedance Zout is set to be substantially equal to the boost ratio Du. That is, equation (2) is established.
  • the secondary resonance circuit 17 is represented by a series equivalent circuit of a secondary capacitor 33, a secondary internal resistance 35, a power receiving coil portion 39, and a non-power receiving coil portion 41. Further, the impedance of the secondary resonance circuit 17 is also influenced by the primary resonance circuit 15. Therefore, it is also necessary to consider the series equivalent circuit of the primary capacitor 25, the primary internal resistance 27, the power transmission coil portion 29, and the non-power transmission coil portion 31 constituting the primary resonance circuit 15. By changing these parameters, the secondary resonance circuit 17 is adjusted to have the output impedance Zout obtained by the equation (2).
  • each parameter is defined as follows. Resistance value of primary internal resistance 27: Primary internal resistance value Rt Resistance value of secondary internal resistance 35: Secondary internal resistance value Rr Reactance of primary resonant circuit 15: primary reactance Xt Reactance of secondary resonant circuit 17: secondary reactance Xr Frequency of power output from power transmission circuit 13: frequency f Inductance of primary coil 23: primary inductance Ltx Inductance of secondary coil 37: secondary inductance Lrx Capacitance value of primary capacitor 25: primary capacitance value Ct Capacitance value of secondary capacitor 33: secondary capacitance value Cr Mutual inductance of power transmission coil portion 29 and power receiving coil portion 39: mutual inductance M Coupling coefficient between power transmission coil portion 29 and power receiving coil portion 39: coupling coefficient k Inductance of non-power transmission coil portion 31: power transmission inductance Lt Inductance of non-power receiving coil portion 41: power receiving inductance Lr From these parameters, the output impedance Zout can be obtained from the following equation.
  • the frequency f can also be changed. Therefore, by adjusting these parameters and calculating the above equations (3) to (8), the impedance of the secondary resonance circuit 17 can be adjusted to the output impedance Zout obtained by the equation (2).
  • the primary internal resistance value Rt and the secondary internal resistance value Rr are determined by the configurations of the primary coil 23 and the secondary coil 37. Thus, when the size, number of turns, wire diameter, etc. of the primary coil 23 change, the primary inductance Ltx and the primary internal resistance value Rt change simultaneously. Similarly, due to the configuration of the secondary coil 37, the secondary inductance Lrx and the secondary internal resistance value Rr change simultaneously. Therefore, it is necessary to adjust in consideration of this point.
  • the operation of the non-contact power feeding device 11A will be described.
  • AC power having a frequency f is output from the power transmission circuit 13
  • power is supplied from the primary resonance circuit 15 to the secondary resonance circuit 17 in a contactless manner.
  • the primary coil 23 generates a magnetic field that changes according to the AC power supplied from the power transmission circuit 13.
  • Inductive power is generated in the secondary coil 37 in accordance with the change in the magnetic field.
  • the AC power received by the secondary resonance circuit 17 is converted into DC power by the rectifier circuit 19.
  • the secondary battery 21 is charged by applying the output voltage of the rectifier circuit 19 to the secondary battery 21.
  • the output impedance Zout of the secondary resonance circuit 17 is adjusted to satisfy the expression (2).
  • the secondary battery impedance ZL increases.
  • the ratio ZL / Zout is configured to be substantially equal to the boost ratio Du, and the boost ratio Du is a predetermined constant value. Therefore, for example, when the secondary battery impedance ZL increases by 10% due to charging, the output impedance Zout also increases by 10%. Thus, the output impedance Zout also increases at the same rate as the secondary battery impedance ZL increases when the secondary battery 21 is charged.
  • the secondary capacitor 33 is formed of, for example, a ceramic capacitor whose capacitance characteristics change with voltage.
  • the secondary battery impedance ZL and the secondary battery voltage Vb rise as the charging of the secondary battery 21 proceeds.
  • the voltage applied to the secondary resonance circuit 17 increases.
  • a ceramic capacitor whose capacitance characteristics change with respect to voltage changes its capacitance when an AC voltage is applied. Therefore, the secondary capacitance value Cr of the secondary capacitor 33 becomes smaller due to the increase of the voltage applied to the secondary resonance circuit 17.
  • the secondary reactance Xr of the secondary resonance circuit 17 increases due to the decrease in the secondary capacitance value Cr. Therefore, the output impedance Zout of the secondary resonance circuit 17 is increased according to the expression (1).
  • an LC matching circuit in which an inductor is connected in series to one end of the rectifier circuit 19 and a capacitor is connected in parallel to the other end of the inductor may be provided.
  • the output impedance Zout can be increased in accordance with the increase in the secondary battery impedance ZL.
  • the secondary battery voltage Vb is determined based on the output impedance Zout and the boost ratio Du (a constant value) of the rectifier circuit 19. Therefore, when the output impedance Zout increases as described above, the secondary battery voltage Vb also increases at the same rate as the increase rate.
  • the output impedance Zout increases at the same rate as the secondary battery impedance ZL increases as the secondary battery 21 is charged.
  • the secondary battery voltage Vb also increases at the same ratio.
  • the secondary battery impedance ZL and the secondary battery voltage Vb increase at the same rate as the secondary battery 21 is charged.
  • the secondary battery 21 may be overcharged. Therefore, in the present embodiment, the secondary battery voltage Vb at the start of charging is determined, and the maximum time during which constant current charging can be performed so that the secondary battery 21 is not overcharged is determined based on the value. That is, at the time of charging, the maximum charging time is determined based on the initial value of the secondary battery voltage Vb. Therefore, the secondary battery 21 can be charged with constant current without particularly measuring the electrical characteristics such as the voltage and current of the secondary battery 21 being charged, and without providing a constant current circuit. Therefore, the cost of the non-contact power feeding device 11A can be reduced. As an application for such charging, for example, it can be applied to non-contact charging such as a smartphone that consumes a large amount of power and has relatively many opportunities to charge after the power of the secondary battery 21 is almost used up.
  • the output impedance Zout is adjusted so that the ratio ZL / Zout is substantially equal to the step-up ratio Du or the step-down ratio Dd of the rectifier circuit 19. Therefore, as the charging of the secondary battery 21 proceeds, the secondary battery voltage Vb and the secondary battery impedance ZL increase at the same ratio. As a result, the charging current Ib becomes constant. In this way, the non-contact power feeding apparatus 11A can charge the secondary battery 21 with a constant current with a simple configuration without a special constant current circuit.
  • the output impedance Zout can be calculated in the same manner although it is different from the above-described equations (3) to (8). Therefore, even in the parallel connection configuration, the output impedance Zout can be adjusted so that the ratio ZL / Zout is substantially equal to the step-up ratio Du or the step-down ratio Dd of the rectifier circuit 19. Therefore, the secondary battery 21 can be charged with a constant current by a non-contact power feeding device having a simple configuration.
  • the rectifier circuit 19 has a configuration in which four diodes 43 are connected in a bridge shape.
  • a single-phase half-wave rectifier circuit may be used.
  • a field effect transistor hereinafter referred to as FET
  • FET field effect transistor
  • the rectifier circuit 19 when the rectifier circuit 19 is operated, all the FETs are turned off to form a bridge circuit with parasitic diodes. Therefore, the same effect as described above can be obtained.
  • the FET when discharging the secondary battery 21, the FET may be controlled to be turned on / off so that a desired voltage is output to a load (not shown).
  • the FET also serves as the rectifier circuit 19 and the switching element of the discharging DC / DC converter. Therefore, both charging and discharging of the secondary battery 21 are possible with a simple configuration.
  • FIG. 2 is a block circuit diagram of the non-contact power feeding device 11B according to Embodiment 2 of the present invention.
  • the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
  • the non-contact power supply device 11B further includes a voltage detection circuit 45 that is electrically connected to the secondary battery 21 and detects the secondary battery voltage Vb.
  • the power transmission circuit 13 stops power transmission when the secondary battery voltage Vb detected by the voltage detection circuit 45 reaches a predetermined voltage Vbk that is higher than the complete discharge voltage Vbe in the secondary battery 21 and lower than the full charge voltage Vbf.
  • a voltage detection circuit 45 that detects the secondary battery voltage Vb is electrically connected to both ends of the secondary battery 21.
  • the voltage detection circuit 45 is connected to the power transmission circuit 13 in a signal manner, and outputs a signal indicating the value of the secondary battery voltage Vb detected by the voltage detection circuit 45 to the power transmission circuit 13.
  • the voltage detection circuit 45 is connected to the power transmission circuit 13 in a non-contact manner. Specifically, as shown in FIG. 2, the output of the voltage detection circuit 45 is wirelessly connected to the power transmission circuit 13 via the antenna 47.
  • a modulation circuit connected to the secondary resonance circuit 17 and a demodulation circuit connected to the primary resonance circuit 15 may be provided (both not shown).
  • the modulation circuit modulates the output of the voltage detection circuit 45 at a frequency different from the frequency f used for power transmission, and transmits the modulated signal from the secondary resonance circuit 17 to the primary resonance circuit 15. And the signal of the secondary battery voltage Vb can be taken out by the demodulation circuit.
  • the power transmission circuit 13 reads a signal of the secondary battery voltage Vb from the voltage detection circuit 45 via the antenna 47 before supplying power to the secondary battery 21.
  • the power transmission circuit 13 determines that the secondary battery 21 is charged with sufficient power and does not transmit power.
  • the predetermined voltage Vbk is a charging completion voltage of the secondary battery 21 and is a voltage higher than the complete discharge voltage Vbe in the secondary battery 21 and lower than the full charge voltage Vbf. The reason for this will be described below.
  • the secondary battery 21 in order to charge the secondary battery included in the load 123 to the full charge voltage Vbf, control for switching between constant current charge and constant voltage charge is performed.
  • the secondary battery 21 in the non-contact power supply apparatus 11B, the secondary battery 21 is charged only by constant current charging as in the first embodiment. Therefore, when the predetermined voltage Vbk is set to the same value as the full charge voltage Vbf, the secondary battery 21 continues to be charged with a constant current up to the full charge voltage. Therefore, the secondary battery 21 may be in an overvoltage state.
  • a voltage for switching from conventional constant current charging to constant voltage charging is predetermined as the predetermined voltage Vbk.
  • the predetermined voltage Vbk is not limited to the voltage for switching from the above-described conventional constant current charging to constant voltage charging, and may be determined as a lower voltage in consideration of a margin.
  • the resistance against the overvoltage of the secondary battery 21 is large, it may be set as a voltage lower than the full charge voltage Vbf but higher than the switching voltage.
  • the predetermined voltage Vbk is set low, the power charged in the secondary battery 21 is reduced. Therefore, it is desirable to set the predetermined voltage Vbk as high as possible within a range that does not place a burden on the secondary battery 21 due to an overvoltage state or the like.
  • the power transmission circuit 13 determines that the secondary battery voltage Vb is lower than the predetermined voltage Vbk, the power transmission circuit 13 starts charging the secondary battery 21 as in the first embodiment. At this time, as described in the first embodiment, the secondary battery 21 is charged with a constant current.
  • the secondary battery voltage Vb increases. This change is read into the power transmission circuit 13 as a change in the signal of the secondary battery voltage Vb.
  • the power transmission circuit 13 stops power transmission to the secondary battery 21 when the secondary battery voltage Vb indicated by this signal reaches the predetermined voltage Vbk. Thereby, the charging of the secondary battery 21 is completed.
  • the secondary battery 21 can be charged with a constant current regardless of the state of charge of the secondary battery 21 in the initial stage of charging. Therefore, the configuration of the present embodiment can be applied to applications in which there are many opportunities to add and charge before the power of the secondary battery 21 is used up, for example, contactless charging of an electric vehicle.
  • the power transmission circuit 13 stops power transmission according to the secondary battery voltage Vb, so that the secondary battery 21 may be overcharged. Can be reduced.
  • a lithium ion battery is used as the secondary battery 21, but other secondary batteries such as a nickel metal hydride battery may be used.
  • the non-contact power supply device according to the present invention is particularly useful as a non-contact power supply device for charging a secondary battery because it can charge a secondary battery at a constant current with a simple configuration.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Power Engineering (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

This non-contact power supply apparatus has a power transmission circuit, a primary resonant circuit, a secondary resonant circuit, a rectifying circuit, and a secondary battery. The primary resonant circuit includes a primary coil, and is electrically connected to the power transmission circuit. The secondary resonant circuit includes a secondary coil that receives power in a non-contact manner when facing the primary coil. The rectifying circuit is electrically connected to the secondary resonant circuit. The secondary battery is electrically connected to the rectifying circuit. When the primary coil and the secondary coil face each other, the secondary resonant circuit has an output impedance (Zout). Furthermore, the secondary battery has a secondary battery impedance (ZL). The output impedance (Zout) is previously set such that the impedance ratio (ZL/Zout) is substantially equal to a voltage increase ratio (Du) or a voltage reduction ratio (Dd) of the rectifying circuit.

Description

非接触給電装置Non-contact power feeding device
　本発明は、非接触で電力を伝送する非接触給電装置に関する。 The present invention relates to a non-contact power feeding device that transmits power in a non-contact manner.
　近年、直接に電気的な接続をせずに、非接触で電力を伝送する給電装置が開発されている。このような給電装置が、例えば特許文献１に提案されている。この種の給電装置の詳細構成を図３に示す。図３は従来の給電装置の構成を示している。 In recent years, power supply devices that transmit power in a contactless manner without direct electrical connection have been developed. Such a power feeding device is proposed in Patent Document 1, for example. A detailed configuration of this type of power feeding apparatus is shown in FIG. FIG. 3 shows a configuration of a conventional power supply apparatus.
　給電側回路１０１は、交流電源部１０３と、直流電源部１０５と、電圧型インバータ１０７と、給電コイル１１１と、一次コンデンサ１１３とを有する。直流電源部１０５は交流電源部１０３から給電された交流電圧を直流電圧に変換する。電圧型インバータ１０７は直流電源部１０５から出力される直流電圧を高周波電力に逆変換する。電圧型インバータ１０７は４つのスイッチＳ１～Ｓ４を含む。給電コイル１１１は電圧型インバータ１０７から出力される高周波電力を受電側回路１０９に非接触で供給する。一次コンデンサ１１３は給電コイル１１１に直列接続されている。 The power supply side circuit 101 includes an AC power supply unit 103, a DC power supply unit 105, a voltage type inverter 107, a power supply coil 111, and a primary capacitor 113. The DC power supply unit 105 converts the AC voltage supplied from the AC power supply unit 103 into a DC voltage. The voltage type inverter 107 reversely converts the DC voltage output from the DC power supply unit 105 into high frequency power. The voltage type inverter 107 includes four switches S 1 to S 4 . The feeding coil 111 supplies the high frequency power output from the voltage type inverter 107 to the power receiving side circuit 109 in a non-contact manner. The primary capacitor 113 is connected in series with the feeding coil 111.
　受電側回路１０９は、受電コイル１１５と、短絡スイッチＳ５と、整流器１１９と、平滑コンデンサ１２１と、バッテリなどの負荷１２３とを有する。受電コイル１１５は給電コイル１１１からの高周波電力を受電する。短絡スイッチＳ５は受電コイル１１５に並列に接続されている。整流器１１９は受電コイル１１５で受電した高周波電力を整流する。平滑コンデンサ１２１は整流器１１９の出力電圧を平滑化する。 The power receiving side circuit 109 includes a power receiving coil 115, a short-circuit switch S 5, a rectifier 119, a smoothing capacitor 121, and a load 123 such as a battery. The power receiving coil 115 receives high frequency power from the power feeding coil 111. Shunt switch S 5 is connected in parallel to the power receiving coil 115. The rectifier 119 rectifies the high frequency power received by the power receiving coil 115. The smoothing capacitor 121 smoothes the output voltage of the rectifier 119.
　電力変換制御部１２５は、負荷制御部１２７からの負荷定電流／定電圧（ＣＣ／ＣＶ）指令に基づき、次のように制御を切り替える。まず、短絡スイッチＳ５のＯＮ／ＯＦＦ切替を制御して負荷１２３の状態に応じて、定電流制御および定電圧制御を切り替える。次に、給電側回路１０１の電圧型インバータ１０７を構成するスイッチＳ１～Ｓ４のＯＮ／ＯＦＦを制御しパルス幅変調（ＰＷＭ）方式による制御によって電圧型インバータ１０７の出力の定電流制御および定電圧制御を切り替える。したがって、電力変換制御部１２５は４つの制御パターンを切り替えることができる。 Based on the load constant current / constant voltage (CC / CV) command from the load control unit 127, the power conversion control unit 125 switches control as follows. First, depending on the state of the load 123 by controlling the ON / OFF switching of the shorting switch S 5, it switches the constant current control and constant voltage control. Next, ON / OFF of the switches S 1 to S 4 constituting the voltage type inverter 107 of the power supply side circuit 101 is controlled, and constant current control and constant control of the output of the voltage type inverter 107 are performed by control by a pulse width modulation (PWM) method. Switch voltage control. Therefore, the power conversion control unit 125 can switch the four control patterns.
特開２０１０－２３３３６４号公報JP 2010-233364 A
　本発明の非接触給電装置は送電回路と、一次共振回路と、二次共振回路と、整流回路と、二次電池とを有する。一次共振回路は一次コイルを含み、送電回路と電気的に接続されている。二次共振回路は、一次コイルと対向した際に、非接触で電力を受電する二次コイルを含む。整流回路は二次共振回路と電気的に接続されている。二次電池は整流回路と電気的に接続されている。一次コイルと二次コイルとを対向させた際、二次共振回路は出力インピーダンスＺｏｕｔを有する。また二次電池は二次電池インピーダンスＺＬを有する。これらのインピーダンスの比ＺＬ／Ｚｏｕｔが整流回路の昇圧比Ｄｕまたは降圧比Ｄｄと実質的に等しくなるように、予め出力インピーダンスＺｏｕｔが設定されている。 The contactless power supply device of the present invention includes a power transmission circuit, a primary resonance circuit, a secondary resonance circuit, a rectifier circuit, and a secondary battery. The primary resonant circuit includes a primary coil and is electrically connected to the power transmission circuit. The secondary resonance circuit includes a secondary coil that receives power in a non-contact manner when facing the primary coil. The rectifier circuit is electrically connected to the secondary resonant circuit. The secondary battery is electrically connected to the rectifier circuit. When the primary coil and the secondary coil are opposed to each other, the secondary resonance circuit has an output impedance Zout. The secondary battery has a secondary battery impedance ZL. The output impedance Zout is set in advance so that the ratio ZL / Zout of these impedances is substantially equal to the step-up ratio Du or step-down ratio Dd of the rectifier circuit.
　以上の構成では、二次電池の充電が進行することにより、二次電池インピーダンスＺＬが上昇するが、これに対応して、二次共振回路の出力インピーダンスＺｏｕｔも上昇する。この際、上記した比（ＺＬ／Ｚｏｕｔ）が、整流回路の昇圧比Ｄｕ、または降圧比Ｄｄと実質的に等しくなるように出力インピーダンスＺｏｕｔが調整されている。そのため、二次電池の充電時に二次電池インピーダンスＺＬが上昇する比率と同じ比率で出力インピーダンスＺｏｕｔも上昇する。ここで、二次電池電圧Ｖｂは、出力インピーダンスＺｏｕｔと整流回路の昇圧比Ｄｕ、または降圧比Ｄｄ（いずれも一定値）に基づいて決まる。したがって、二次電池インピーダンスＺＬが上昇する比率と同じ比率で二次電池電圧Ｖｂが上昇する。二次電池への充電電流Ｉｂは二次電池電圧Ｖｂを二次電池インピーダンスＺＬで除することで決まるため、二次電池電圧Ｖｂと二次電池インピーダンスＺＬが同じ比率で上昇すると、充電電流Ｉｂは一定となる。このように、非接触給電装置は特段の定電流回路が無い簡単な構成で二次電池を定電流充電することができる。 In the above configuration, the secondary battery impedance ZL increases as the charging of the secondary battery proceeds. Correspondingly, the output impedance Zout of the secondary resonance circuit also increases. At this time, the output impedance Zout is adjusted so that the above-described ratio (ZL / Zout) is substantially equal to the step-up ratio Du or step-down ratio Dd of the rectifier circuit. Therefore, the output impedance Zout also increases at the same rate as the rate at which the secondary battery impedance ZL increases when the secondary battery is charged. Here, the secondary battery voltage Vb is determined based on the output impedance Zout and the step-up ratio Du or step-down ratio Dd (both are constant values) of the rectifier circuit. Accordingly, the secondary battery voltage Vb increases at the same rate as the secondary battery impedance ZL increases. Since the charging current Ib to the secondary battery is determined by dividing the secondary battery voltage Vb by the secondary battery impedance ZL, when the secondary battery voltage Vb and the secondary battery impedance ZL increase at the same ratio, the charging current Ib is It becomes constant. Thus, the non-contact power feeding device can charge the secondary battery with a constant current with a simple configuration without a special constant current circuit.
本発明の実施の形態１における非接触給電装置のブロック回路図Block circuit diagram of the non-contact power feeding device in Embodiment 1 of the present invention 本発明の実施の形態２における非接触給電装置のブロック回路図Block circuit diagram of a non-contact power feeding device in Embodiment 2 of the present invention 従来の給電装置の給電装置の構成を示す図The figure which shows the structure of the electric power feeder of the conventional electric power feeder
　本発明の実施の形態の説明に先立ち、図３に示す従来の給電装置における課題を簡単に説明する。図３に示した給電装置では、４つの制御パターンを切り替えることで、負荷１２３を定電流／定電圧充電することができる。しかしながら、そのために電力変換制御部１２５の構成、制御は複雑である。しかも、電力変換制御部１２５は、給電側回路１０１におけるスイッチＳ１～Ｓ４と、受電側回路１０９の短絡スイッチＳ５とを制御する必要や、受電コイル１１５および負荷１２３の電圧をモニターする必要がある。このように、電力変換制御部１２５は給電側回路１０１と、受電側回路１０９の両方に関与する必要があり、非接触給電装置として複雑である。 Prior to the description of the embodiment of the present invention, problems in the conventional power feeding apparatus shown in FIG. 3 will be briefly described. In the power supply apparatus illustrated in FIG. 3, the load 123 can be charged with constant current / constant voltage by switching four control patterns. However, the configuration and control of the power conversion control unit 125 are complicated for that purpose. Moreover, the power conversion control unit 125 needs to control the switches S 1 to S 4 in the power supply side circuit 101 and the short-circuit switch S 5 in the power reception side circuit 109, and monitor the voltages of the power reception coil 115 and the load 123. There is. As described above, the power conversion control unit 125 needs to be involved in both the power feeding side circuit 101 and the power receiving side circuit 109, and is complicated as a non-contact power feeding device.
　以下、簡単な構成で二次電池を充電することができる本発明の実施の形態による非接触給電装置について、図面を参照しながら説明する。 Hereinafter, a non-contact power feeding device according to an embodiment of the present invention capable of charging a secondary battery with a simple configuration will be described with reference to the drawings.
　（実施の形態１）
　図１は、本発明の実施の形態１における非接触給電装置１１Ａのブロック回路図である。非接触給電装置１１Ａは送電回路１３と、一次共振回路１５と、二次共振回路１７と、整流回路１９と、二次電池２１とを有する。一次共振回路１５は一次コイルを含み、送電回路１３と電気的に接続されている。二次共振回路１７は、一次コイル２３と対向した際に、非接触で電力を受電する二次コイル３７を含む。整流回路１９は二次共振回路１７と電気的に接続されている。二次電池２１は整流回路１９と電気的に接続されている。送電回路１３と一次共振回路１５とは給電部を構成し、二次共振回路１７と整流回路１９と二次電池２１とは受電部を構成している。 (Embodiment 1)
FIG. 1 is a block circuit diagram of a non-contact power supply apparatus 11A according to Embodiment 1 of the present invention. The contactless power supply device 11 </ b> A includes a power transmission circuit 13, a primary resonance circuit 15, a secondary resonance circuit 17, a rectifier circuit 19, and a secondary battery 21. The primary resonance circuit 15 includes a primary coil and is electrically connected to the power transmission circuit 13. The secondary resonant circuit 17 includes a secondary coil 37 that receives power in a non-contact manner when facing the primary coil 23. The rectifier circuit 19 is electrically connected to the secondary resonance circuit 17. The secondary battery 21 is electrically connected to the rectifier circuit 19. The power transmission circuit 13 and the primary resonance circuit 15 constitute a power supply unit, and the secondary resonance circuit 17, the rectifier circuit 19, and the secondary battery 21 constitute a power reception unit.
　一次コイル２３と二次コイル３７とを対向させた際、二次共振回路１７は出力インピーダンスＺｏｕｔを有する。また二次電池２１は二次電池インピーダンスＺＬを有する。これらのインピーダンスの比ＺＬ／Ｚｏｕｔが整流回路１９の昇圧比Ｄｕまたは降圧比Ｄｄと実質的に等しくなるように、予め出力インピーダンスＺｏｕｔが設定されている。 When the primary coil 23 and the secondary coil 37 are opposed to each other, the secondary resonance circuit 17 has an output impedance Zout. The secondary battery 21 has a secondary battery impedance ZL. The output impedance Zout is set in advance so that the ratio ZL / Zout of these impedances is substantially equal to the step-up ratio Du or the step-down ratio Dd of the rectifier circuit 19.
　二次電池２１の充電状態が進行すると、二次電池インピーダンスＺＬが上昇する。非接触給電装置１１Ａでは、これに対応して、二次共振回路１７の出力インピーダンスＺｏｕｔも上昇する。この際、上記した比ＺＬ／Ｚｏｕｔが、整流回路１９の昇圧比Ｄｕ、または降圧比Ｄｄと実質的に等しくなるように出力インピーダンスＺｏｕｔが調整されている。そのため、二次電池２１の充電時に二次電池インピーダンスＺＬが上昇する比率と同じ比率で出力インピーダンスＺｏｕｔも上昇する。 When the charging state of the secondary battery 21 proceeds, the secondary battery impedance ZL increases. In the non-contact power feeding device 11A, the output impedance Zout of the secondary resonance circuit 17 also increases correspondingly. At this time, the output impedance Zout is adjusted so that the ratio ZL / Zout is substantially equal to the step-up ratio Du or the step-down ratio Dd of the rectifier circuit 19. Therefore, the output impedance Zout also increases at the same rate as the secondary battery impedance ZL increases when the secondary battery 21 is charged.
　二次電池電圧Ｖｂは、出力インピーダンスＺｏｕｔと整流回路１９の昇圧比Ｄｕ、または降圧比Ｄｄ（いずれも一定値）に基づいて決まる。そのため、二次電池インピーダンスＺＬが上昇する比率と同じ比率で二次電池電圧Ｖｂが上昇する。したがって、二次電池２１への充電電流Ｉｂは二次電池電圧Ｖｂを二次電池インピーダンスＺＬで除することで決まる。このように、二次電池電圧Ｖｂと二次電池インピーダンスＺＬが同じ比率で上昇すると、充電電流Ｉｂは一定となる。ゆえに、非接触給電装置１１Ａは、特段の定電流回路が無い簡単な構成で二次電池２１を定電流充電することができる。 The secondary battery voltage Vb is determined based on the output impedance Zout and the step-up ratio Du or step-down ratio Dd (both are constant values) of the rectifier circuit 19. Therefore, the secondary battery voltage Vb rises at the same rate as the rate at which the secondary battery impedance ZL rises. Therefore, the charging current Ib to the secondary battery 21 is determined by dividing the secondary battery voltage Vb by the secondary battery impedance ZL. Thus, when the secondary battery voltage Vb and the secondary battery impedance ZL increase at the same ratio, the charging current Ib becomes constant. Therefore, the non-contact power feeding apparatus 11A can charge the secondary battery 21 with a constant current with a simple configuration without a special constant current circuit.
　以下、より具体的に非接触給電装置１１Ａの構成、動作について説明する。送電回路１３は、例えば商用の系統電源（図示せず）からの電力を非接触給電に必要な周波数ｆを有する交流電力に変換する。したがって、送電回路１３が動作することにより、非接触給電が開始される。送電回路１３には、一次共振回路１５が電気的に接続されている。一次共振回路１５は送電回路１３からの電力を二次共振回路１７へ送電するために設けられている。一次共振回路１５は、一次コイル２３と、共振回路を構成するための一次コンデンサ２５とが電気的に直列に接続された構成を有する。一次共振回路１５には一次コイル２３における一次内部抵抗２７が含まれる。一次コイル２３は、等価回路的には、実際の送電に寄与する送電コイル部分２９と、それ以外の非送電コイル部分３１との直列回路で構成されている。したがって、一次共振回路１５は、一次コンデンサ２５、一次内部抵抗２７、一次コイル２３の直列回路で構成されている。 Hereinafter, the configuration and operation of the non-contact power feeding apparatus 11A will be described more specifically. The power transmission circuit 13 converts, for example, power from a commercial system power supply (not shown) into AC power having a frequency f necessary for non-contact power feeding. Therefore, non-contact power feeding is started when the power transmission circuit 13 operates. A primary resonance circuit 15 is electrically connected to the power transmission circuit 13. The primary resonance circuit 15 is provided to transmit power from the power transmission circuit 13 to the secondary resonance circuit 17. The primary resonant circuit 15 has a configuration in which a primary coil 23 and a primary capacitor 25 for configuring the resonant circuit are electrically connected in series. The primary resonance circuit 15 includes a primary internal resistance 27 in the primary coil 23. In terms of an equivalent circuit, the primary coil 23 includes a series circuit including a power transmission coil portion 29 that contributes to actual power transmission and a non-power transmission coil portion 31 other than that. Therefore, the primary resonance circuit 15 is configured by a series circuit of the primary capacitor 25, the primary internal resistance 27, and the primary coil 23.
　二次共振回路１７の構成は、一次共振回路１５の構成と同様である。すなわち、二次共振回路１７は、二次コンデンサ３３、二次内部抵抗３５、および二次コイル３７の直列回路で構成されている。二次コイル３７は一次コイル２３と対向して配置可能である。二次コイル３７が一次コイル２３に対向した際に、一次コイル２３から送電された電力が、非接触で二次コイル３７により受電される。なお、二次コイル３７は、一次コイル２３と同様、等価回路的には、実際の受電に寄与する受電コイル部分３９と、それ以外の非受電コイル部分４１との直列回路で構成されている。 The configuration of the secondary resonance circuit 17 is the same as the configuration of the primary resonance circuit 15. That is, the secondary resonance circuit 17 is configured by a series circuit of a secondary capacitor 33, a secondary internal resistor 35, and a secondary coil 37. The secondary coil 37 can be arranged to face the primary coil 23. When the secondary coil 37 faces the primary coil 23, the power transmitted from the primary coil 23 is received by the secondary coil 37 in a non-contact manner. As with the primary coil 23, the secondary coil 37 is configured by a series circuit of a power receiving coil portion 39 that contributes to actual power reception and other non-power receiving coil portions 41 in terms of an equivalent circuit.
　二次共振回路１７には整流回路１９が電気的に接続されている。整流回路１９は二次共振回路１７が受電した交流電力を直流電力に変換する。具体的には図１に示すように、整流回路１９は４つのダイオード４３をブリッジ状に接続した構成を有する。 A rectifier circuit 19 is electrically connected to the secondary resonance circuit 17. The rectifier circuit 19 converts AC power received by the secondary resonance circuit 17 into DC power. Specifically, as shown in FIG. 1, the rectifier circuit 19 has a configuration in which four diodes 43 are connected in a bridge shape.
　整流回路１９において、入力電圧に対する出力電圧との比を昇圧比Ｄｕという。なお、本実施の形態では、整流回路１９が昇圧する構成であるため、以下、昇圧比Ｄｕを用いて説明するが、整流回路１９が降圧する構成の場合は降圧比Ｄｄを有する。その場合、以下の説明で「昇圧比Ｄｕ」を「降圧比Ｄｄ」と読み替えればよい。 In the rectifier circuit 19, the ratio of the input voltage to the output voltage is referred to as a boost ratio Du. In the present embodiment, since the rectifier circuit 19 is configured to step up, the following description will be made using the step-up ratio Du. However, the configuration in which the rectifier circuit 19 steps down has a step-down ratio Dd. In that case, the “step-up ratio Du” may be read as “step-down ratio Dd” in the following description.
　整流回路１９には、二次電池２１が電気的に接続されている。したがって、送電回路１３で出力された電力は、非接触で二次電池２１に充電される。なお、本実施の形態では、二次電池２１としてリチウムイオン電池を用いている。また、本実施の形態では、二次電池２１のみが整流回路１９に接続される充電器としての構成であるが、二次電池２１から電力が供給される負荷（図示せず）が接続されていてもよい。 A secondary battery 21 is electrically connected to the rectifier circuit 19. Therefore, the power output from the power transmission circuit 13 is charged in the secondary battery 21 in a non-contact manner. In the present embodiment, a lithium ion battery is used as the secondary battery 21. In the present embodiment, only the secondary battery 21 is configured as a charger connected to the rectifier circuit 19, but a load (not shown) to which power is supplied from the secondary battery 21 is connected. May be.
　二次電池２１に使用しているリチウムイオン電池は、定電流で充電すると、満充電に至るよりも低い充電状態の場合に充電が進行する。このとき、二次電池電圧Ｖｂは充電時間の経過に伴い直線的に増加する。したがって、二次電池インピーダンスＺＬは、二次電池２１を定電流の充電電流Ｉｂで充電した時に、（１）式を用いて求めることができる。（１）式を用いて、まず、使用する二次電池２１の二次電池インピーダンスＺＬを予め求める。 When the lithium ion battery used for the secondary battery 21 is charged at a constant current, the charging proceeds in a charged state lower than the full charge. At this time, the secondary battery voltage Vb increases linearly as the charging time elapses. Therefore, the secondary battery impedance ZL can be obtained using the equation (1) when the secondary battery 21 is charged with the constant charging current Ib. First, the secondary battery impedance ZL of the secondary battery 21 to be used is obtained in advance using the equation (1).
　ＺＬ＝Ｖｂ／Ｉｂ　　（１）
　次に、整流回路１９の昇圧比Ｄｕを求める。昇圧比Ｄｕは、使用するダイオード４３により一義的に決まる。 ZL = Vb / Ib (1)
Next, the boost ratio Du of the rectifier circuit 19 is obtained. The step-up ratio Du is uniquely determined by the diode 43 used.
　こうして求められた二次電池インピーダンスＺＬと昇圧比Ｄｕより、二次共振回路１７における出力インピーダンスＺｏｕｔを決定する。前述のように、出力インピーダンスＺｏｕｔに対する二次電池インピーダンスＺＬの比ＺＬ／Ｚｏｕｔは、昇圧比Ｄｕと実質的に等しくなるように設定される。すなわち、（２）式が成り立っている。 The output impedance Zout in the secondary resonance circuit 17 is determined from the secondary battery impedance ZL thus obtained and the step-up ratio Du. As described above, the ratio ZL / Zout of the secondary battery impedance ZL to the output impedance Zout is set to be substantially equal to the boost ratio Du. That is, equation (2) is established.
　ＺＬ／Ｚｏｕｔ＝Ｄｕ　∴Ｚｏｕｔ＝ＺＬ／Ｄｕ　　　　（２）
　なお、「実質的に等しくなる」とは、二次電池電圧Ｖｂ、充電電流Ｉｂ、昇圧比Ｄｕの精度と、（１）、（２）式の計算精度を含む誤差範囲内で等しいという意味である。このようにして得られた出力インピーダンスＺｏｕｔを有するように二次共振回路１７を調整する。具体的には、次のようにして調整する。 ZL / Zout = Du Zout = ZL / Du (2)
Note that “substantially equal” means that the accuracy of the secondary battery voltage Vb, the charging current Ib, and the step-up ratio Du is equal to the error range including the calculation accuracy of the equations (1) and (2). is there. The secondary resonance circuit 17 is adjusted to have the output impedance Zout obtained in this way. Specifically, the adjustment is performed as follows.
　まず、図１に示すように、二次共振回路１７は、二次コンデンサ３３、二次内部抵抗３５、受電コイル部分３９、および非受電コイル部分４１の直列等価回路で表される。また、二次共振回路１７のインピーダンスは、一次共振回路１５によっても影響される。したがって、一次共振回路１５を構成する一次コンデンサ２５、一次内部抵抗２７、送電コイル部分２９、および非送電コイル部分３１の直列等価回路も考慮する必要がある。これらのパラメータを変えることで二次共振回路１７が、（２）式で求めた出力インピーダンスＺｏｕｔを有するように調整する。 First, as shown in FIG. 1, the secondary resonance circuit 17 is represented by a series equivalent circuit of a secondary capacitor 33, a secondary internal resistance 35, a power receiving coil portion 39, and a non-power receiving coil portion 41. Further, the impedance of the secondary resonance circuit 17 is also influenced by the primary resonance circuit 15. Therefore, it is also necessary to consider the series equivalent circuit of the primary capacitor 25, the primary internal resistance 27, the power transmission coil portion 29, and the non-power transmission coil portion 31 constituting the primary resonance circuit 15. By changing these parameters, the secondary resonance circuit 17 is adjusted to have the output impedance Zout obtained by the equation (2).
　ここで、各パラメータを以下のように定義する。
一次内部抵抗２７の抵抗値：一次内部抵抗値Ｒｔ
二次内部抵抗３５の抵抗値：二次内部抵抗値Ｒｒ
一次共振回路１５のリアクタンス：一次リアクタンスＸｔ
二次共振回路１７のリアクタンス：二次リアクタンスＸｒ
送電回路１３から出力される電力の周波数：周波数ｆ
一次コイル２３のインダクタンス：一次インダクタンスＬｔｘ
二次コイル３７のインダクタンス：二次インダクタンスＬｒｘ
一次コンデンサ２５の容量値：一次容量値Ｃｔ
二次コンデンサ３３の容量値：二次容量値Ｃｒ
送電コイル部分２９と受電コイル部分３９の相互インダクタンス：相互インダクタンスＭ
送電コイル部分２９と受電コイル部分３９との結合係数：結合係数ｋ
非送電コイル部分３１のインダクタンス：送電インダクタンスＬｔ
非受電コイル部分４１のインダクタンス：受電インダクタンスＬｒ
　これらのパラメータより、出力インピーダンスＺｏｕｔは以下の式から求められる。 Here, each parameter is defined as follows.
Resistance value of primary internal resistance 27: Primary internal resistance value Rt
Resistance value of secondary internal resistance 35: Secondary internal resistance value Rr
Reactance of primary resonant circuit 15: primary reactance Xt
Reactance of secondary resonant circuit 17: secondary reactance Xr
Frequency of power output from power transmission circuit 13: frequency f
Inductance of primary coil 23: primary inductance Ltx
Inductance of secondary coil 37: secondary inductance Lrx
Capacitance value of primary capacitor 25: primary capacitance value Ct
Capacitance value of secondary capacitor 33: secondary capacitance value Cr
Mutual inductance of power transmission coil portion 29 and power receiving coil portion 39: mutual inductance M
Coupling coefficient between power transmission coil portion 29 and power receiving coil portion 39: coupling coefficient k
Inductance of non-power transmission coil portion 31: power transmission inductance Lt
Inductance of non-power receiving coil portion 41: power receiving inductance Lr
From these parameters, the output impedance Zout can be obtained from the following equation.
　Ｚｏｕｔ＝Ｒｒ＋Ｘｒ・Ｒｔ／Ｘｔ　　　　　　　　（３）
　Ｘｔ＝２πｆ・Ｌｔ－１／（２πｆ・Ｃｔ）　　　　（４）
　Ｘｒ＝２πｆ・Ｌｒ－１／（２πｆ・Ｃｒ）　　　　（５）
　Ｌｒ＝Ｌｒｘ－Ｍ　　　　　　　　　　　　　　　　（６）
　Ｌｔ＝Ｌｔｘ－Ｍ　　　　　　　　　　　　　　　　（７）
　Ｍ＝ｋ（Ｌｔｘ・Ｌｒｘ）１／２　　　　　　　　　　（８）
　一次インダクタンスＬｔｘ、二次インダクタンスＬｒｘ、および結合係数ｋは、一次コイル２３と二次コイル３７の構成（大きさ、巻数、線径など）の設計と、両者の位置関係により変えることができる。また、一次容量値Ｃｔと二次容量値Ｃｒも変えることができる。さらに、周波数ｆも変更できる。したがって、これらのパラメータを調整し、上記（３）～（８）式を計算することにより、二次共振回路１７のインピーダンスを、（２）式で求めた出力インピーダンスＺｏｕｔに調整することができる。なお、一次内部抵抗値Ｒｔと二次内部抵抗値Ｒｒは一次コイル２３と二次コイル３７の構成によって決まる。このように一次コイル２３の大きさ、巻数、線径などが変わると、一次インダクタンスＬｔｘと一次内部抵抗値Ｒｔが同時に変化する。同様に、二次コイル３７の構成により、二次インダクタンスＬｒｘと二次内部抵抗値Ｒｒが同時に変化する。したがって、この点を考慮して調整する必要がある。 Zout = Rr + Xr · Rt / Xt (3)
Xt = 2πf · Lt−1 / (2πf · Ct) (4)
Xr = 2πf · Lr−1 / (2πf · Cr) (5)
Lr = Lrx-M (6)
Lt = Ltx-M (7)
M = k (Ltx · Lrx) 1/2 (8)
The primary inductance Ltx, the secondary inductance Lrx, and the coupling coefficient k can be changed according to the design (size, number of turns, wire diameter, etc.) of the primary coil 23 and the secondary coil 37 and the positional relationship between them. Further, the primary capacitance value Ct and the secondary capacitance value Cr can also be changed. Furthermore, the frequency f can also be changed. Therefore, by adjusting these parameters and calculating the above equations (3) to (8), the impedance of the secondary resonance circuit 17 can be adjusted to the output impedance Zout obtained by the equation (2). The primary internal resistance value Rt and the secondary internal resistance value Rr are determined by the configurations of the primary coil 23 and the secondary coil 37. Thus, when the size, number of turns, wire diameter, etc. of the primary coil 23 change, the primary inductance Ltx and the primary internal resistance value Rt change simultaneously. Similarly, due to the configuration of the secondary coil 37, the secondary inductance Lrx and the secondary internal resistance value Rr change simultaneously. Therefore, it is necessary to adjust in consideration of this point.
　次に非接触給電装置１１Ａの動作について説明する。送電回路１３から周波数ｆの交流電力が出力されると、一次共振回路１５から二次共振回路１７へ、非接触で電力が供給される。具体的には、一次コイル２３は、送電回路１３から供給された交流電力に応じて変化する磁場を発生する。二次コイル３７には、この磁場の変化に応じて誘導電力（交流電力）が発生する。 Next, the operation of the non-contact power feeding device 11A will be described. When AC power having a frequency f is output from the power transmission circuit 13, power is supplied from the primary resonance circuit 15 to the secondary resonance circuit 17 in a contactless manner. Specifically, the primary coil 23 generates a magnetic field that changes according to the AC power supplied from the power transmission circuit 13. Inductive power (AC power) is generated in the secondary coil 37 in accordance with the change in the magnetic field.
　二次共振回路１７が受電した交流電力は、整流回路１９で直流電力に変換される。この際、整流回路１９の出力電圧（＝二次電池電圧Ｖｂ）は、入力電圧を昇圧比Ｄｕで昇圧した値となる。整流回路１９の出力電圧が二次電池２１に印加されることにより、二次電池２１が充電される。 The AC power received by the secondary resonance circuit 17 is converted into DC power by the rectifier circuit 19. At this time, the output voltage (= secondary battery voltage Vb) of the rectifier circuit 19 is a value obtained by boosting the input voltage by the boost ratio Du. The secondary battery 21 is charged by applying the output voltage of the rectifier circuit 19 to the secondary battery 21.
　このような充電動作において、前述のように二次共振回路１７の出力インピーダンスＺｏｕｔは、（２）式を満たすように調整されている。一方、二次電池２１の充電が進行するとともに二次電池インピーダンスＺＬは上昇する。ここで、比ＺＬ／Ｚｏｕｔが昇圧比Ｄｕと実質的に等しくなるように構成されており、また、昇圧比Ｄｕは予め決まった一定値である。したがって、例えば二次電池インピーダンスＺＬが充電により１０％上昇すると、出力インピーダンスＺｏｕｔも１０％上昇する。このように、二次電池２１の充電時に二次電池インピーダンスＺＬが上昇する比率と同じ比率で出力インピーダンスＺｏｕｔも上昇する。 In such a charging operation, as described above, the output impedance Zout of the secondary resonance circuit 17 is adjusted to satisfy the expression (2). On the other hand, as the charging of the secondary battery 21 proceeds, the secondary battery impedance ZL increases. Here, the ratio ZL / Zout is configured to be substantially equal to the boost ratio Du, and the boost ratio Du is a predetermined constant value. Therefore, for example, when the secondary battery impedance ZL increases by 10% due to charging, the output impedance Zout also increases by 10%. Thus, the output impedance Zout also increases at the same rate as the secondary battery impedance ZL increases when the secondary battery 21 is charged.
　ここで、二次コンデンサ３３は、電圧に対して容量特性が変化する、例えば、セラミックコンデンサで構成される。二次電池インピーダンスＺＬと二次電池電圧Ｖｂは、二次電池２１の充電が進行するとともに上昇する。二次電池電圧Ｖｂが上昇すると、二次共振回路１７に印加される電圧が上昇する。電圧に対して容量特性が変化するセラミックコンデンサは、交流電圧を印加することで容量が変化する。したがって、二次共振回路１７に印加される電圧の上昇により、二次コンデンサ３３の二次容量値Ｃｒは小さくなる。すると、（５）式から、二次容量値Ｃｒの低下により二次共振回路１７の二次リアクタンスＸｒが上昇する。そのため、（１）式により、二次共振回路１７の出力インピーダンスＺｏｕｔは大きくなる。なお、整流回路１９の一端に直列にインダクタを接続し、インダクタの他端に並列にコンデンサを接続したＬＣ整合回路を設ける構成としてもよい。 Here, the secondary capacitor 33 is formed of, for example, a ceramic capacitor whose capacitance characteristics change with voltage. The secondary battery impedance ZL and the secondary battery voltage Vb rise as the charging of the secondary battery 21 proceeds. When the secondary battery voltage Vb increases, the voltage applied to the secondary resonance circuit 17 increases. A ceramic capacitor whose capacitance characteristics change with respect to voltage changes its capacitance when an AC voltage is applied. Therefore, the secondary capacitance value Cr of the secondary capacitor 33 becomes smaller due to the increase of the voltage applied to the secondary resonance circuit 17. Then, from equation (5), the secondary reactance Xr of the secondary resonance circuit 17 increases due to the decrease in the secondary capacitance value Cr. Therefore, the output impedance Zout of the secondary resonance circuit 17 is increased according to the expression (1). Note that an LC matching circuit in which an inductor is connected in series to one end of the rectifier circuit 19 and a capacitor is connected in parallel to the other end of the inductor may be provided.
　このような構成とすることにより、二次電池インピーダンスＺＬの上昇に応じて、出力インピーダンスＺｏｕｔを上昇させることができる。 With such a configuration, the output impedance Zout can be increased in accordance with the increase in the secondary battery impedance ZL.
　一方、二次電池電圧Ｖｂは、出力インピーダンスＺｏｕｔと整流回路１９の昇圧比Ｄｕ（一定値）に基づいて決まる。したがって、出力インピーダンスＺｏｕｔが上述のように上昇すると、その上昇比率と同じ比率で二次電池電圧Ｖｂも上昇する。 On the other hand, the secondary battery voltage Vb is determined based on the output impedance Zout and the boost ratio Du (a constant value) of the rectifier circuit 19. Therefore, when the output impedance Zout increases as described above, the secondary battery voltage Vb also increases at the same rate as the increase rate.
　これらのことをまとめると、二次電池２１の充電とともに二次電池インピーダンスＺＬが上昇する比率と同じ比率で出力インピーダンスＺｏｕｔが上昇する。出力インピーダンスＺｏｕｔが上昇すると、それと同じ比率で二次電池電圧Ｖｂも上昇する。その結果、二次電池インピーダンスＺＬと二次電池電圧Ｖｂは二次電池２１の充電とともに同じ比率で上昇することになる。 In summary, the output impedance Zout increases at the same rate as the secondary battery impedance ZL increases as the secondary battery 21 is charged. When the output impedance Zout increases, the secondary battery voltage Vb also increases at the same ratio. As a result, the secondary battery impedance ZL and the secondary battery voltage Vb increase at the same rate as the secondary battery 21 is charged.
　ここで、（１）式より、充電電流Ｉｂは二次電池電圧Ｖｂを二次電池インピーダンスＺＬで除する（Ｉｂ＝Ｖｂ／ＺＬ）ことで決まる。また、二次電池電圧Ｖｂと二次電池インピーダンスＺＬは二次電池２１の充電とともに、同じ比率で上昇する。したがって、例えば、二次電池インピーダンスＺＬが１０％上昇すると、二次電池電圧Ｖｂも１０％上昇するので、二次電池電圧Ｖｂを二次電池インピーダンスＺＬで除することにより得られる充電電流Ｉｂは、（９）式により求められる。 Here, from the equation (1), the charging current Ib is determined by dividing the secondary battery voltage Vb by the secondary battery impedance ZL (Ib = Vb / ZL). Further, the secondary battery voltage Vb and the secondary battery impedance ZL increase at the same ratio as the secondary battery 21 is charged. Therefore, for example, if the secondary battery impedance ZL increases by 10%, the secondary battery voltage Vb also increases by 10%. Therefore, the charging current Ib obtained by dividing the secondary battery voltage Vb by the secondary battery impedance ZL is: It is calculated | required by (9) Formula.
　Ｉｂ＝１．１×Ｖｂ／（１．１×ＺＬ）＝Ｖｂ／ＺＬ　（９）
　二次電池２１の充電により、二次電池インピーダンスＺＬが何％上昇しても、（９）式に示すように、上昇比率分が約分される。ゆえに、二次電池２１への充電電流Ｉｂは一定値となり、定電流充電が可能となる。 Ib = 1.1 × Vb / (1.1 × ZL) = Vb / ZL (9)
As the secondary battery 21 is charged, no matter how much the secondary battery impedance ZL increases, the increase ratio is reduced as shown in the equation (9). Therefore, the charging current Ib to the secondary battery 21 is a constant value, and constant current charging is possible.
　なお、定電流充電を継続すると、二次電池２１が過充電となる可能性がある。そこで、本実施の形態では、充電開始時の二次電池電圧Ｖｂが決まっていて、その値から、二次電池２１が過充電にならないように定電流充電できる最大時間が予め定められている。すなわち、充電時には、二次電池電圧Ｖｂの初期値に基づき充電最大時間が決まっている。したがって、充電中の二次電池２１の電圧、電流などの電気特性を特に測定することなく、また、定電流回路などを設けることなく、二次電池２１を定電流充電することができる。そのため、非接触給電装置１１Ａのコストを小さくすることができる。このような充電のための用途としては、例えば消費電力が大きく、二次電池２１の電力をほぼ使い切ってから充電する機会が比較的多いスマートフォンなどの非接触充電などに適用できる。 If the constant current charging is continued, the secondary battery 21 may be overcharged. Therefore, in the present embodiment, the secondary battery voltage Vb at the start of charging is determined, and the maximum time during which constant current charging can be performed so that the secondary battery 21 is not overcharged is determined based on the value. That is, at the time of charging, the maximum charging time is determined based on the initial value of the secondary battery voltage Vb. Therefore, the secondary battery 21 can be charged with constant current without particularly measuring the electrical characteristics such as the voltage and current of the secondary battery 21 being charged, and without providing a constant current circuit. Therefore, the cost of the non-contact power feeding device 11A can be reduced. As an application for such charging, for example, it can be applied to non-contact charging such as a smartphone that consumes a large amount of power and has relatively many opportunities to charge after the power of the secondary battery 21 is almost used up.
　以上の構成により、比ＺＬ／Ｚｏｕｔが、整流回路１９の昇圧比Ｄｕ、または降圧比Ｄｄと実質的に等しくなるように出力インピーダンスＺｏｕｔが調整されている。そのため、二次電池２１の充電が進行することにより、二次電池電圧Ｖｂと二次電池インピーダンスＺＬが同じ比率で上昇する。その結果、充電電流Ｉｂが一定となる。このように、非接触給電装置１１Ａは、特段の定電流回路が無い簡単な構成で二次電池２１を定電流充電することができる。 With the above configuration, the output impedance Zout is adjusted so that the ratio ZL / Zout is substantially equal to the step-up ratio Du or the step-down ratio Dd of the rectifier circuit 19. Therefore, as the charging of the secondary battery 21 proceeds, the secondary battery voltage Vb and the secondary battery impedance ZL increase at the same ratio. As a result, the charging current Ib becomes constant. In this way, the non-contact power feeding apparatus 11A can charge the secondary battery 21 with a constant current with a simple configuration without a special constant current circuit.
　なお、本実施の形態では、一次コイル２３と一次コンデンサ２５、および二次コイル３７と二次コンデンサ３３が、いずれも直列接続された構成について説明している。これ以外に、コイルとコンデンサが並列接続された構成であってもよい。この場合、出力インピーダンスＺｏｕｔは上記した（３）～（８）式とは異なるものの、同様に計算することができる。したがって、並列接続の構成であっても、比ＺＬ／Ｚｏｕｔが、整流回路１９の昇圧比Ｄｕ、または降圧比Ｄｄと実質的に等しくなるように出力インピーダンスＺｏｕｔを調整することができる。したがって、簡単な構成の非接触給電装置で二次電池２１を定電流充電することができる。 In the present embodiment, a configuration in which the primary coil 23 and the primary capacitor 25, and the secondary coil 37 and the secondary capacitor 33 are all connected in series is described. In addition, a configuration in which a coil and a capacitor are connected in parallel may be used. In this case, the output impedance Zout can be calculated in the same manner although it is different from the above-described equations (3) to (8). Therefore, even in the parallel connection configuration, the output impedance Zout can be adjusted so that the ratio ZL / Zout is substantially equal to the step-up ratio Du or the step-down ratio Dd of the rectifier circuit 19. Therefore, the secondary battery 21 can be charged with a constant current by a non-contact power feeding device having a simple configuration.
　また、本実施の形態では、整流回路１９は、４つのダイオード４３をブリッジ状に接続した構成を有している。これ以外に、例えば、単相半波整流回路でもよい。あるいは、ダイオード４３に代えて電界効果トランジスタ（以下、ＦＥＴという）を用いてもよい。この場合、整流回路１９として動作させる時は、全てのＦＥＴをオフにすることで、寄生ダイオードによりブリッジ回路が構成される。そのため、上述と同じ効果が得られる。さらに、二次電池２１を放電する際に、ＦＥＴをオンオフ制御することで、図示しない負荷へ所望の電圧を出力するように構成してもよい。この場合、ＦＥＴは、整流回路１９と、放電用のＤＣ／ＤＣコンバータのスイッチング素子の役割を兼ねる。したがって、簡単な構成で二次電池２１の充電と放電の両方が可能となる。 In the present embodiment, the rectifier circuit 19 has a configuration in which four diodes 43 are connected in a bridge shape. In addition to this, for example, a single-phase half-wave rectifier circuit may be used. Alternatively, a field effect transistor (hereinafter referred to as FET) may be used in place of the diode 43. In this case, when the rectifier circuit 19 is operated, all the FETs are turned off to form a bridge circuit with parasitic diodes. Therefore, the same effect as described above can be obtained. Furthermore, when discharging the secondary battery 21, the FET may be controlled to be turned on / off so that a desired voltage is output to a load (not shown). In this case, the FET also serves as the rectifier circuit 19 and the switching element of the discharging DC / DC converter. Therefore, both charging and discharging of the secondary battery 21 are possible with a simple configuration.
　（実施の形態２）
　図２は、本発明の実施の形態２における非接触給電装置１１Ｂのブロック回路図である。本実施の形態において、実施の形態１と同じ構成については同じ符号を付し、詳細な説明を省略する。 (Embodiment 2)
FIG. 2 is a block circuit diagram of the non-contact power feeding device 11B according to Embodiment 2 of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
　非接触給電装置１１Ｂは、非接触給電装置１１Ａの構成に加え、二次電池２１に電気的に接続され、二次電池電圧Ｖｂを検出する電圧検出回路４５をさらに有する。送電回路１３は、電圧検出回路４５で検出された二次電池電圧Ｖｂが、二次電池２１における完全放電電圧Ｖｂｅより高く、満充電電圧Ｖｂｆより低い所定電圧Ｖｂｋに至れば、送電を停止する。 In addition to the configuration of the non-contact power supply device 11A, the non-contact power supply device 11B further includes a voltage detection circuit 45 that is electrically connected to the secondary battery 21 and detects the secondary battery voltage Vb. The power transmission circuit 13 stops power transmission when the secondary battery voltage Vb detected by the voltage detection circuit 45 reaches a predetermined voltage Vbk that is higher than the complete discharge voltage Vbe in the secondary battery 21 and lower than the full charge voltage Vbf.
　この構成により、二次電池電圧Ｖｂの初期値がばらつく用途であっても、二次電池電圧Ｖｂが所定電圧Ｖｂｋに至ると、送電回路１３は送電を停止する。そのため、二次電池２１を過充電する可能性を低減することができる。 With this configuration, even when the initial value of the secondary battery voltage Vb varies, when the secondary battery voltage Vb reaches the predetermined voltage Vbk, the power transmission circuit 13 stops power transmission. Therefore, the possibility of overcharging the secondary battery 21 can be reduced.
　以下、本実施の形態の特徴となる詳細構成について説明する。二次電池２１の両端には、二次電池電圧Ｖｂを検出する電圧検出回路４５が電気的に接続されている。電圧検出回路４５は送電回路１３に信号的に接続され、電圧検出回路４５で検出した二次電池電圧Ｖｂの値を示す信号を送電回路１３へ出力する。 Hereinafter, a detailed configuration that characterizes the present embodiment will be described. A voltage detection circuit 45 that detects the secondary battery voltage Vb is electrically connected to both ends of the secondary battery 21. The voltage detection circuit 45 is connected to the power transmission circuit 13 in a signal manner, and outputs a signal indicating the value of the secondary battery voltage Vb detected by the voltage detection circuit 45 to the power transmission circuit 13.
　なお送電回路１３からの電力は非接触で二次電池２１へ供給されるので、電圧検出回路４５は送電回路１３に非接触で接続されている。具体的には、図２に示すように、電圧検出回路４５の出力は、アンテナ４７を介して無線で送電回路１３と接続されている。 In addition, since the electric power from the power transmission circuit 13 is supplied to the secondary battery 21 in a non-contact manner, the voltage detection circuit 45 is connected to the power transmission circuit 13 in a non-contact manner. Specifically, as shown in FIG. 2, the output of the voltage detection circuit 45 is wirelessly connected to the power transmission circuit 13 via the antenna 47.
　なお、アンテナ４７を用いる以外に、二次共振回路１７に接続された変調回路と、一次共振回路１５に接続された復調回路を設けてもよい（いずれも図示せず）。この構成では、変調回路が電圧検出回路４５の出力を、電力伝送に使われる周波数ｆと異なる周波数で変調して二次共振回路１７から一次共振回路１５へ送信する。そして、復調回路で二次電池電圧Ｖｂの信号を取り出すことができる。 In addition to using the antenna 47, a modulation circuit connected to the secondary resonance circuit 17 and a demodulation circuit connected to the primary resonance circuit 15 may be provided (both not shown). In this configuration, the modulation circuit modulates the output of the voltage detection circuit 45 at a frequency different from the frequency f used for power transmission, and transmits the modulated signal from the secondary resonance circuit 17 to the primary resonance circuit 15. And the signal of the secondary battery voltage Vb can be taken out by the demodulation circuit.
　上記以外の構成は実施の形態１と同じである。 Other configurations are the same as those in the first embodiment.
　次に、非接触給電装置１１Ｂの動作について、特徴となる部分を説明する。まず、送電回路１３は、二次電池２１への電力供給の前に、電圧検出回路４５からアンテナ４７を介して、二次電池電圧Ｖｂの信号を読み込む。 Next, a characteristic part of the operation of the non-contact power feeding device 11B will be described. First, the power transmission circuit 13 reads a signal of the secondary battery voltage Vb from the voltage detection circuit 45 via the antenna 47 before supplying power to the secondary battery 21.
　次に、読み込んだ信号が示す二次電池電圧Ｖｂが所定電圧Ｖｂｋ以上であれば、送電回路１３は二次電池２１に十分な電力が充電されていると判断し、送電しない。ここで、所定電圧Ｖｂｋとは、二次電池２１の充電完了電圧のことであり、二次電池２１における完全放電電圧Ｖｂｅより高く、満充電電圧Ｖｂｆより低い電圧である。この理由を以下に説明する。 Next, if the secondary battery voltage Vb indicated by the read signal is equal to or higher than the predetermined voltage Vbk, the power transmission circuit 13 determines that the secondary battery 21 is charged with sufficient power and does not transmit power. Here, the predetermined voltage Vbk is a charging completion voltage of the secondary battery 21 and is a voltage higher than the complete discharge voltage Vbe in the secondary battery 21 and lower than the full charge voltage Vbf. The reason for this will be described below.
　図３に示す従来の給電装置の構成では、負荷１２３に含まれる二次電池を満充電電圧Ｖｂｆまで充電するためには、定電流充電と定電圧充電を切り替える制御を行なう。しかし、非接触給電装置１１Ｂでは、実施の形態１と同様にして定電流充電のみで二次電池２１を充電する。そのため、所定電圧Ｖｂｋを満充電電圧Ｖｂｆと同じ値にすると、二次電池２１は満充電電圧まで定電流で充電され続ける。そのため、二次電池２１が過電圧状態となる可能性がある。 3, in order to charge the secondary battery included in the load 123 to the full charge voltage Vbf, control for switching between constant current charge and constant voltage charge is performed. However, in the non-contact power supply apparatus 11B, the secondary battery 21 is charged only by constant current charging as in the first embodiment. Therefore, when the predetermined voltage Vbk is set to the same value as the full charge voltage Vbf, the secondary battery 21 continues to be charged with a constant current up to the full charge voltage. Therefore, the secondary battery 21 may be in an overvoltage state.
　したがって、本実施の形態では、満充電電圧Ｖｂｆより低い電圧として、例えば、従来の定電流充電から定電圧充電に切り替える電圧を所定電圧Ｖｂｋとして予め定めている。なお、所定電圧Ｖｂｋは上記した従来の定電流充電から定電圧充電に切り替える電圧に限定されるものではなく、マージンを考慮して、それよりも低い電圧として決定してもよい。二次電池２１の過電圧に対する耐性が大きい場合は、満充電電圧Ｖｂｆより低いが、上記の切り替え電圧より高い電圧として設定してもよい。但し、所定電圧Ｖｂｋを低く設定すると、二次電池２１に充電される電力が少なくなる。したがって、過電圧状態などにより、二次電池２１に負担のかからない範囲で、できるだけ所定電圧Ｖｂｋを高く設定する方が望ましい。 Therefore, in the present embodiment, as a voltage lower than the full charge voltage Vbf, for example, a voltage for switching from conventional constant current charging to constant voltage charging is predetermined as the predetermined voltage Vbk. The predetermined voltage Vbk is not limited to the voltage for switching from the above-described conventional constant current charging to constant voltage charging, and may be determined as a lower voltage in consideration of a margin. When the resistance against the overvoltage of the secondary battery 21 is large, it may be set as a voltage lower than the full charge voltage Vbf but higher than the switching voltage. However, when the predetermined voltage Vbk is set low, the power charged in the secondary battery 21 is reduced. Therefore, it is desirable to set the predetermined voltage Vbk as high as possible within a range that does not place a burden on the secondary battery 21 due to an overvoltage state or the like.
　なお、送電回路１３は、二次電池電圧Ｖｂが所定電圧Ｖｂｋより低いと判断すれば、実施の形態１と同様にして二次電池２１の充電を開始する。この際、実施の形態１で述べたように、二次電池２１は定電流で充電される。 Note that if the power transmission circuit 13 determines that the secondary battery voltage Vb is lower than the predetermined voltage Vbk, the power transmission circuit 13 starts charging the secondary battery 21 as in the first embodiment. At this time, as described in the first embodiment, the secondary battery 21 is charged with a constant current.
　二次電池２１への定電流充電が進行すると、二次電池電圧Ｖｂが上昇する。この変化は二次電池電圧Ｖｂの信号の変化として送電回路１３に読み込まれる。そして、送電回路１３は、この信号が示す二次電池電圧Ｖｂが所定電圧Ｖｂｋに至れば、二次電池２１への送電を停止する。これにより、二次電池２１の充電が完了する。 When the constant current charging to the secondary battery 21 proceeds, the secondary battery voltage Vb increases. This change is read into the power transmission circuit 13 as a change in the signal of the secondary battery voltage Vb. The power transmission circuit 13 stops power transmission to the secondary battery 21 when the secondary battery voltage Vb indicated by this signal reaches the predetermined voltage Vbk. Thereby, the charging of the secondary battery 21 is completed.
　このような動作により、充電初期における二次電池２１の充電状態にかかわらず、二次電池２１を定電流充電することができる。したがって、本実施の形態の構成は、二次電池２１の電力を使い切るよりも前に、継ぎ足し充電する機会が多い用途、例えば電気自動車の非接触充電などに適用できる。 By such an operation, the secondary battery 21 can be charged with a constant current regardless of the state of charge of the secondary battery 21 in the initial stage of charging. Therefore, the configuration of the present embodiment can be applied to applications in which there are many opportunities to add and charge before the power of the secondary battery 21 is used up, for example, contactless charging of an electric vehicle.
　以上の構成により、二次電池電圧Ｖｂの初期値がばらつく用途であっても、送電回路１３が二次電池電圧Ｖｂに応じて送電を停止するので、二次電池２１を過充電する可能性を低減することができる。 With the above configuration, even if the initial value of the secondary battery voltage Vb varies, the power transmission circuit 13 stops power transmission according to the secondary battery voltage Vb, so that the secondary battery 21 may be overcharged. Can be reduced.
　なお、実施の形態１、２において、二次電池２１としてリチウムイオン電池を用いているが、ニッケル水素電池など他の二次電池であってもよい。 In the first and second embodiments, a lithium ion battery is used as the secondary battery 21, but other secondary batteries such as a nickel metal hydride battery may be used.
　本発明にかかる非接触給電装置は、簡単な構成で二次電池を定電流充電することができるので、特に二次電池充電用の非接触給電装置等として有用である。 The non-contact power supply device according to the present invention is particularly useful as a non-contact power supply device for charging a secondary battery because it can charge a secondary battery at a constant current with a simple configuration.
１１Ａ，１１Ｂ　　非接触給電装置
１３　　送電回路
１５　　一次共振回路
１７　　二次共振回路
１９　　整流回路
２１　　二次電池
２３　　一次コイル
２５　　一次コンデンサ
２７　　一次内部抵抗
２９　　送電コイル部分
３１　　非送電コイル部分
３３　　二次コンデンサ
３５　　二次内部抵抗
３７　　二次コイル
３９　　受電コイル部分
４１　　非受電コイル部分
４３　　ダイオード
４５　　電圧検出回路
４７　　アンテナ 11A, 11B Non-contact power feeding device 13 Power transmission circuit 15 Primary resonance circuit 17 Secondary resonance circuit 19 Rectifier circuit 21 Secondary battery 23 Primary coil 25 Primary capacitor 27 Primary internal resistance 29 Power transmission coil portion 31 Non-power transmission coil portion 33 Secondary capacitor 35 Secondary internal resistance 37 Secondary coil 39 Power receiving coil portion 41 Non power receiving coil portion 43 Diode 45 Voltage detection circuit 47 Antenna

Claims (3)

  1. 送電回路と、
    一次コイルを含み、前記送電回路と電気的に接続された一次共振回路と、
    前記一次コイルと対向した際に、非接触で電力を受電する二次コイルを含む二次共振回路と、
    前記二次共振回路と電気的に接続された整流回路と、
    前記整流回路と電気的に接続された二次電池と、を備え、
    前記一次コイルと前記二次コイルとを対向させた際の、前記二次共振回路における出力インピーダンスに対する、前記二次電池における二次電池インピーダンスの比が、前記整流回路の昇圧比または降圧比と実質的に等しくなるように、前記二次共振回路の前記出力インピーダンスが設定されている、
    非接触給電装置。     A power transmission circuit;
    A primary resonant circuit including a primary coil and electrically connected to the power transmission circuit;
    A secondary resonance circuit including a secondary coil that receives power in a non-contact manner when facing the primary coil;
    A rectifier circuit electrically connected to the secondary resonant circuit;
    A secondary battery electrically connected to the rectifier circuit,
    The ratio of the secondary battery impedance in the secondary battery to the output impedance in the secondary resonance circuit when the primary coil and the secondary coil face each other is substantially equal to the step-up ratio or the step-down ratio of the rectifier circuit. The output impedance of the secondary resonant circuit is set to be equal to each other,
    Non-contact power feeding device.
  2. 前記二次電池に電気的に接続され、前記二次電池の電圧を検出する電圧検出回路をさらに備え、
    前記電圧検出回路で検出される前記二次電池の前記電圧が、前記二次電池における満充電電圧より低い第１電圧に至れば、前記送電回路は送電を停止する、
    請求項１記載の非接触給電装置。     A voltage detection circuit that is electrically connected to the secondary battery and detects a voltage of the secondary battery;
    When the voltage of the secondary battery detected by the voltage detection circuit reaches a first voltage lower than a full charge voltage in the secondary battery, the power transmission circuit stops power transmission.
    The contactless power feeding device according to claim 1.
  3. 前記二次共振回路は、印加された交流電圧によって容量特性が変化する二次コンデンサをさらに含む、
    請求項１記載の非接触給電装置。     The secondary resonant circuit further includes a secondary capacitor whose capacitance characteristics change according to the applied AC voltage.
    The contactless power feeding device according to claim 1.
PCT/JP2013/007533 2012-12-28 2013-12-24 Non-contact power supply apparatus WO2014103280A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012287101 2012-12-28
JP2012-287101 2012-12-28

Publications (1)

Publication Number Publication Date
WO2014103280A1 true WO2014103280A1 (en) 2014-07-03

Family

ID=51020398

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/007533 WO2014103280A1 (en) 2012-12-28 2013-12-24 Non-contact power supply apparatus

Country Status (1)

Country Link
WO (1) WO2014103280A1 (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010233364A (en) * 2009-03-27 2010-10-14 Nissan Motor Co Ltd Power supply device
WO2012014483A1 (en) * 2010-07-29 2012-02-02 Kabushiki Kaisha Toyota Jidoshokki Resonance type non-contact power supply system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010233364A (en) * 2009-03-27 2010-10-14 Nissan Motor Co Ltd Power supply device
WO2012014483A1 (en) * 2010-07-29 2012-02-02 Kabushiki Kaisha Toyota Jidoshokki Resonance type non-contact power supply system

Similar Documents

Publication Publication Date Title
US10978246B2 (en) Wireless power transmitter and method of controlling power thereof
US8987941B2 (en) Power transmission system
US9948144B2 (en) Power transmission system and power transmission device used for power transmission system
JP6394632B2 (en) Wireless power transmission system
EP3787170A1 (en) Dcdc converter, vehicle-mounted charger and electric vehicle
JP5826547B2 (en) Power supply side equipment and resonance type non-contact power supply system
JP5550785B2 (en) Circuit of contactless inductive power transmission system
US10277082B2 (en) Power-transmitting device and wireless power-supplying system
US10312741B2 (en) Electronic unit and power feeding system
US9887553B2 (en) Electric power transmission device, and electric power reception device and vehicle including the same
EP3098938B1 (en) Charger having battery diagnosis function and method of driving the same
WO2016172916A1 (en) Transmitter-side control of wireless power transfer systems without using mutual coupling information or wireless feedback
US9466987B2 (en) Power transmission device and wireless power transmission system using the power transmission device
WO2014199691A1 (en) Power supply device and non-contact power supply system
KR20160036986A (en) Wireless power transmitter and wireless power receiver
JP6037022B2 (en) Power transmission device, wireless power transmission system, and power transmission discrimination method
JP2013198260A (en) Power transmission system
JP2016063726A (en) Power receiving apparatus and non-contact power transmission device
CN110582922A (en) Non-contact power supply device
WO2015004778A1 (en) Power-transfer system
JP6111625B2 (en) Wireless power transmission equipment
WO2014045873A1 (en) Power receiving device and contactless power transmitting equipment
JP6310846B2 (en) Non-contact power transmission system and secondary battery pack
WO2015083578A1 (en) Contactless power transmission device and electricity reception apparatus
WO2014069148A1 (en) Non-contact power transmission device, and power reception apparatus

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13868288

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13868288

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP