JP2015065756A - Power-receiving device and power-transmitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve sharing of components of a filter circuit and to prevent change in system characteristics due to providing the filter circuit, in a power-receiving device receiving power from a power-transmitting device in a non-contact manner.SOLUTION: A filter circuit 150 is provided between a power-receiving section 100 and a rectification section 200, and is composed of a fourth-order LC filter including inductors 154 and 158 and capacitors 152 and 156. The inductance of respective inductors 154 and 158 is the same to each other, and the capacitance of respective capacitors 152 and 156 is the same to each other. When each inductance of the inductors 154 and 158 is L and the frequency of transmission power is f, each capacitance of the capacitors 152 and 156 is set to be C≒2/(L×(2πf)).

Description

  The present invention relates to a power reception device and a power transmission device, and more particularly to a power reception device and a power transmission device used in a power transmission system that transmits power from the power transmission device to the power reception device in a contactless manner.

  In recent years, attention has been focused on non-contact power transmission that transmits power in a non-contact manner. Japanese Patent Laying-Open No. 2002-49428 (Patent Document 1) discloses an immittance converter used in a non-contact power feeding device that realizes such non-contact power transmission. The immittance converter includes a fourth-order filter including first and second reactors and first and second capacitors. The first and second reactors have a first inductance pL (0 <p <1) and a second inductance L, respectively. The first and second capacitors have a first capacitance C and a second capacitance (1-p) C, respectively.

  According to this immittance converter, harmonics of the resonance frequency fr can be suppressed, and furthermore, changes in the output current and output voltage can be suppressed even if the resonance frequency fr changes (Patent Document). 1).

JP 2002-49428 A JP2013-154815A JP2013-146154A JP2013-146148A JP 2013-110822 A JP 2013-126327 A

  In the immittance converter (filter circuit) described in Patent Document 1, the inductance of the first reactor is different from the inductance of the second reactor, and the capacitance of the first capacitor is different from the capacitance of the second capacitor. Cannot be shared.

  In addition, since the above-described immittance converter (filter circuit) changes the current / voltage gain of the converter with respect to changes in L and C and changes in the load state, by providing an immittance converter, System characteristics may change and the need to change the system design may arise.

  The present invention has been made to solve such a problem, and an object thereof is to share filter circuit components and provide a filter circuit in a power receiving device that receives power from a power transmitting device in a contactless manner. It is to suppress the change of the system characteristics due to.

  Another object of the present invention is to share filter circuit components in a power transmission device that transmits power to a power receiving device in a contactless manner, and to suppress changes in system characteristics due to the provision of the filter circuit. .

According to this invention, the power reception device includes a power reception unit, a rectification unit, and a filter circuit. The power receiving unit receives the power output from the power transmission device in a contactless manner. The rectifying unit rectifies the power received by the power receiving unit. The filter circuit is provided between the power reception unit and the rectification unit. The filter circuit includes first and second inductors and first and second capacitors. The first and second inductors are provided in at least one of the power line pair connected between the power reception unit and the rectification unit. The first and second capacitors are each connected between the power line pair, and are alternately provided with the first and second inductors between the power receiving unit and the rectifying unit. The inductance of the first inductor is equal to the inductance of the second inductor. The capacitance of the first capacitor is equal to the capacitance of the second capacitor. The capacitance is set to C≈2 / (L × (2πf) ² ) where L is the inductance and f is the frequency of the power.

  In this power receiving apparatus, since the inductance of the first inductor is equal to the inductance of the second inductor, and the capacitance of the first capacitor is equal to the capacitance of the second capacitor, the first and second inductors are shared. The first and second capacitors can be shared. Also, by setting the capacitance C of the first and second capacitors as described above, the filter circuit has a current / voltage gain of 1 for the fundamental wave (frequency f), which is higher than the fundamental wave. It functions as a normal LC filter for frequency waves (such as harmonics). Therefore, according to the power receiving device, it is possible to share the components of the filter circuit and to suppress changes in system characteristics due to the provision of the filter circuit.

Preferably, when C0 = 2 / (L × (2πf) ² ), the capacitance is set in a range of 0.9 × C0 <C <1.1 × C0.

  In an actual system, there are variations in the frequency f and parts constituting the filter circuit. According to this power receiving device, by setting the capacitance C of the first and second capacitors within the above range, the current / voltage gain deviates from 1, but a significant decrease in the efficiency of the filter circuit is avoided. Can do.

  Preferably, the power reception unit includes a power reception coil and a series capacitor connected in series to the power reception coil. The first and second inductors and the first and second capacitors are provided in the order of the first capacitor, the first inductor, the second capacitor, and the second inductor from the power receiving unit side.

  In a configuration in which the power reception unit includes a series capacitor, when an inductor is provided in the first stage of the filter circuit (position closest to the power reception unit), the resonance state of the power reception unit is affected by the inductance of the inductor. According to this power reception device, since the first capacitor is provided in the first stage of the filter circuit, it is possible to avoid the influence of the filter circuit on the resonance state of the power reception unit.

  Preferably, the power reception unit includes a power reception coil and a parallel capacitor connected in parallel to the power reception coil. The first and second inductors and the first and second capacitors are provided in the order of the first inductor, the first capacitor, the second inductor, and the second capacitor from the power receiving unit side.

  In a configuration in which the power receiving unit includes a parallel capacitor, if a capacitor is provided in the first stage of the filter circuit, the resonance state of the power receiving unit is affected by the capacitance of the capacitor. According to this power reception device, since the first inductor is provided in the first stage of the filter circuit, it is possible to avoid the influence of the filter circuit on the resonance state of the power reception unit.

  Preferably, the power reception unit includes a power reception coil and a series capacitor connected in series to the power reception coil. The rectifier includes a capacitor input rectifier circuit.

  In a configuration in which the power reception unit includes a series capacitor, the power reception unit is a current source for the rectification unit. In such a case, if a choke coil that prevents current change is provided immediately after the rectifier circuit, the input current is distorted and the power factor is reduced. According to this power reception device, the rectification unit includes the capacitor input rectifier circuit in which the choke coil is not provided immediately after the rectifier circuit.

  Preferably, the power reception unit includes a power reception coil and a parallel capacitor connected in parallel to the power reception coil. The rectifier includes a choke input rectifier circuit.

  In a configuration in which the power reception unit includes a parallel capacitor, the power reception unit is a voltage source for the rectification unit. In such a case, if the choke coil that prevents the current change is not provided immediately after the rectifier circuit, the current becomes pulsed and the power factor decreases. According to this power reception device, the rectification unit includes the choke input type rectifier circuit in which the choke coil is provided immediately after the rectifier circuit.

Moreover, according to this invention, a power transmission apparatus is provided with AC power supply, a power transmission part, and a filter circuit. The power transmission unit receives power from the AC power supply and transmits power to the power receiving device in a contactless manner. The filter circuit is provided between the AC power source and the power transmission unit. The filter circuit includes first and second inductors and first and second capacitors. The first and second inductors are provided in at least one of the power line pair connected between the AC power source and the power transmission unit. The first and second capacitors are each connected between a pair of power lines, and are alternately provided with the first and second inductors between the AC power source and the power transmission unit. The inductance of the first inductor is equal to the inductance of the second inductor. The capacitance of the first capacitor is equal to the capacitance of the second capacitor. The capacitance is set to C≈2 / (L × (2πf) ² ) when the inductance is L and the frequency of the AC power supply is f.

  In this power transmission device, since the inductance of the first inductor is equal to the inductance of the second inductor and the capacitance of the first capacitor is equal to the capacitance of the second capacitor, the first and second inductors are shared. The first and second capacitors can be shared. Also, by setting the capacitance C of the first and second capacitors as described above, the filter circuit has a current / voltage gain of 1 for the fundamental wave (frequency f), which is higher than the fundamental wave. It functions as a normal LC filter for frequency waves (such as harmonics). Therefore, according to this power transmission device, it is possible to share the components of the filter circuit and suppress changes in system characteristics due to the provision of the filter circuit.

Preferably, when C0 = 2 / (L × (2πf) ² ), the capacitance is set in a range of 0.9 × C0 <C <1.1 × C0.

  According to this power transmission device, by setting the capacitance C of the first and second capacitors within the above range, the current / voltage gain deviates from 1, but a significant decrease in the efficiency of the filter circuit is avoided. Can do.

  Preferably, the AC power supply includes an inverter that outputs a rectangular wave voltage. The first and second inductors and the first and second capacitors are provided in the order of the first inductor, the first capacitor, the second inductor, and the second capacitor from the AC power supply side.

  When a capacitor is provided in the first stage of the filter circuit (position closest to the power receiving unit) for the inverter that outputs a rectangular wave voltage, a large pulsed current flows through the capacitor. According to this power transmission device, since the first inductor is provided in the first stage of the filter circuit, it is possible to suppress the flow of the large current as described above.

  Preferably, the power transmission unit includes a power transmission coil and a parallel capacitor connected in parallel to the power transmission coil. The first and second inductors and the first and second capacitors are provided in the order of the first capacitor, the first inductor, the second capacitor, and the second inductor from the AC power supply side. The AC power supply includes a current source inverter.

  In a configuration in which the power transmission unit includes a parallel capacitor, when a capacitor is provided in the final stage of the filter circuit (position closest to the power transmission unit), the resonance state of the power transmission unit is affected by the capacitance of the capacitor. According to this power transmission device, since the second inductor is provided at the final stage of the filter circuit, it is possible to avoid the influence of the filter circuit on the resonance state of the power transmission unit. On the other hand, the first capacitor is provided in the first stage of the filter circuit. When an AC power supply is configured by an inverter that outputs a rectangular wave voltage, a large current flows from the AC power supply to the first capacitor as described above. According to this power transmission device, since the AC power source includes the current source inverter, it is possible to suppress a large current from flowing from the AC power source to the first capacitor of the filter circuit.

  According to the present invention, it is possible to share the components of the filter circuit and to suppress changes in system characteristics due to the provision of the filter circuit.

1 is an overall configuration diagram of a power transmission system according to Embodiment 1 of the present invention. It is the figure which showed arrangement | positioning of a receiving part when the vehicle 10 is seen from the side. It is the figure which showed arrangement | positioning of a receiving part when the vehicle 10 is seen from upper direction. It is a circuit diagram which shows the structure of the electric power transmission system shown in FIG. 1 in detail. It is the figure which showed the equivalent circuit of the filter circuit with respect to a fundamental wave. FIG. 5 is a circuit diagram of the rectifying unit shown in FIG. 4. It is a circuit diagram of the power supply part shown in FIG. It is the figure which showed the output waveform of the voltage source inverter. It is the figure which showed the modification of the filter circuit provided in a vehicle. It is the figure which showed the modification of the filter circuit provided in a power transmission apparatus. 6 is a circuit diagram of a power transmission system according to Embodiment 2. FIG. It is a circuit diagram of the rectification | straightening part shown in FIG. 6 is a circuit diagram of a power transmission system in a third embodiment. FIG. It is a circuit diagram of the power supply part shown in FIG. It is the figure which showed the modification of the rectification | straightening part. It is the figure which showed the modification of the electric power transmission part. It is the figure which showed the other modification of the electric power transmission part. It is the figure which showed the other modification of the electric power transmission part.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
1 is an overall configuration diagram of a power transmission system according to Embodiment 1 of the present invention. Referring to FIG. 1, the power transmission system according to the first embodiment includes a vehicle 10 and a power transmission device 20. Vehicle 10 includes a power reception unit 100, a filter circuit 150, a rectification unit 200, a power storage device 300, a power generation device 400, and a vehicle ECU (Electronic Control Unit) 500.

  The power reception unit 100 includes a coil for receiving power (AC) output from a power transmission unit 700 (described later) of the power transmission device 20 in a contactless manner. The power receiving unit 100 outputs the received power to the rectifying unit 200. In the first embodiment, as shown in FIGS. 2 and 3, the power transmission device 20 is provided on the ground surface or in the ground, and the power receiving unit 100 is provided in the lower part of the vehicle body near the front of the vehicle body.

  In addition, the arrangement | positioning location of the power receiving part 100 is not limited to this. For example, the power receiving unit 100 may be provided in the lower part of the vehicle body closer to the rear of the vehicle body. If the power transmission device 20 is provided in the upper part of the vehicle, the power receiving unit 100 may be provided in the upper part of the vehicle body. The detailed configuration of the power receiving unit 100 will be described later.

  The rectifying unit 200 rectifies the AC power received by the power receiving unit 100 and outputs the rectified power to the power storage device 300. The filter circuit 150 is provided between the power reception unit 100 and the rectification unit 200, and suppresses harmonic noise generated when receiving power from the power transmission device 20. The filter circuit 150 includes a fourth-order LC filter including two inductors and two capacitors. The detailed configuration of the filter circuit 150 will be described later.

  The power storage device 300 is a rechargeable DC power source, and is configured by a secondary battery such as lithium ion or nickel metal hydride. The voltage of power storage device 300 is, for example, about 200V. The power storage device 300 stores power output from the rectifying unit 200 and also stores power generated by the power generation device 400. Then, power storage device 300 supplies the stored power to power generation device 400. Note that a large-capacity capacitor can also be used as the power storage device 300. Although not particularly illustrated, a DC-DC converter that adjusts the output voltage of the rectifying unit 200 may be provided between the rectifying unit 200 and the power storage device 300.

  Power generation device 400 generates a driving force for driving vehicle 10 using electric power stored in power storage device 300. Although not particularly illustrated, power generation device 400 includes, for example, an inverter that receives electric power from power storage device 300, a motor driven by the inverter, a drive wheel driven by the motor, and the like. Power generation device 400 may include a generator for charging power storage device 300 and an engine capable of driving the generator.

  The vehicle ECU 500 includes a CPU (Central Processing Unit), a storage device, an input / output buffer, and the like (all not shown), and inputs signals from various sensors and outputs control signals to each device. Control each device in. As an example, vehicle ECU 500 executes traveling control of vehicle 10 and charging control of power storage device 300. Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  Note that a relay 210 is provided between the rectifying unit 200 and the power storage device 300. Relay 210 is turned on by vehicle ECU 500 when power storage device 300 is charged by power transmission device 20. A system main relay (SMR) 310 is provided between the power storage device 300 and the power generation device 400. SMR 310 is turned on by vehicle ECU 500 when activation of power generation device 400 is requested.

  Vehicle ECU 500 communicates with power transmission device 20 using communication device 510 when power storage device 300 is charged by power transmission device 20, and transmits information such as charging start / stop and power reception status of vehicle 10 with power transmission device 20. Interact.

  Power transmission device 20 includes a power supply unit 600, a filter circuit 610, a power transmission unit 700, and a power supply ECU 800. The power supply unit 600 receives power from an external power supply 900 such as a commercial power supply and generates AC power having a predetermined transmission frequency.

  Power transmission unit 700 includes a coil for transmitting power to power reception unit 100 of vehicle 10 in a contactless manner. The power transmission unit 700 receives AC power having a transmission frequency from the power supply unit 600 and transmits the AC power to the power reception unit 100 of the vehicle 10 in a non-contact manner via an electromagnetic field generated around the power transmission unit 700. The detailed configuration of the power transmission unit 700 will be described later.

  Filter circuit 610 is provided between power supply unit 600 and power transmission unit 700, and suppresses harmonic noise generated from power supply unit 600. The filter circuit 610 is configured by a fourth-order LC filter including two inductors and two capacitors. The detailed configuration of the filter circuit 610 will be described later.

  The power supply ECU 800 includes a CPU, a storage device, an input / output buffer, and the like (all not shown), and inputs signals from various sensors and outputs control signals to each device. Take control. As an example, power supply ECU 800 performs switching control of power supply unit 600 such that power supply unit 600 generates AC power having a transmission frequency. Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  The power supply ECU 800 communicates with the vehicle 10 using the communication device 810 during power transmission to the vehicle 10, and exchanges information such as charging start / stop and the power reception status of the vehicle 10 with the vehicle 10.

  In the power transmission device 20, AC power having a predetermined transmission frequency is supplied from the power supply unit 600 to the power transmission unit 700 via the filter circuit 610. Each of power transmission unit 700 and power reception unit 100 of vehicle 10 includes a coil and a capacitor (described later), and is designed to resonate at a transmission frequency. The Q value indicating the resonance intensity of the power transmission unit 700 and the power reception unit 100 is preferably 100 or more.

  When AC power is supplied from the power supply unit 600 to the power transmission unit 700 via the filter circuit 610, power is received from the power transmission unit 700 through an electromagnetic field formed between the coil of the power transmission unit 700 and the coil of the power reception unit 100. Energy (electric power) moves to the unit 100. Then, the energy (electric power) that has moved to power reception unit 100 is supplied to power storage device 300 via filter circuit 150 and rectification unit 200.

  Although not particularly illustrated, in power transmission device 20, an insulating transformer may be provided between power transmission unit 700 and power supply unit 600 (for example, between power transmission unit 700 and filter circuit 610). Also in vehicle 10, an insulating transformer may be provided between power reception unit 100 and rectification unit 200 (for example, between power reception unit 100 and filter circuit 150).

  FIG. 4 is a circuit diagram showing the configuration of the power transmission system shown in FIG. 1 in more detail. Referring to FIG. 4, power reception unit 100 in vehicle 10 includes a coil 110 and a capacitor 120. The capacitor 120 is connected in series with the coil 110 to form a resonance circuit with the coil 110. The capacitor 120 is provided to adjust the resonance frequency of the power receiving unit 100.

  Filter circuit 150 includes capacitors 152 and 156 and inductors 154 and 158. Inductors 154 and 158 are provided on one of the power line pairs between power reception unit 100 and rectification unit 200. In the first embodiment, inductors 154 and 158 are connected in series between terminals T1 and T3. Capacitor 152 is connected between the power line pair on the power receiving unit 100 side with respect to inductor 154. Capacitor 156 is connected between the power line pair between inductors 154 and 158. That is, the capacitors 152 and 156 and the inductors 154 and 158 are provided in the order of the capacitor 152, the inductor 154, the capacitor 156, and the inductor 158 from the power receiving unit 100 side.

  In the filter circuit 150, the inductance of the inductor 154 is equal to the inductance of the inductor 158. Further, the capacitance of the capacitor 152 is equal to the capacitance of the capacitor 156. Capacitance Cf2 of capacitors 152 and 156 is set to a value represented by the following expression (1).

  Here, Lf2 is the inductance of the inductors 154 and 158, and f0 is the frequency of power transmitted from the power transmission device 20 to the vehicle 10 (corresponding to the frequency of power generated by the power supply unit 600 of the power transmission device 20). is there. The angular frequency ω0 = 2πf0.

  By setting the capacitance Cf2 of the capacitors 152 and 156 based on the equation (1), the filter circuit 150 has a voltage / current gain of 1 for the fundamental wave of the frequency f0, and has a frequency ( For harmonics, etc., it functions as a normal fourth-order LC filter. Hereinafter, this point will be described.

  The input voltage of the filter circuit 150 (voltage between the terminals T1 and T2) is Vfin2, the frequency is f (angular frequency ω = 2πf), and the output voltage of the filter circuit 150 (voltage between the terminals T3 and T4) is Vfout2. Then, the relationship between the input voltage Vfin2 and the output voltage Vfout2 is expressed by the following equation (2).

  Substituting equation (1) into equation (2) yields equation (3) below.

  When ω = ω0 in the equation (3), the following equation (4) is obtained.

  From the equation (4), the filter circuit 150 is equivalent to an ideal transformer having a turns ratio of 1 for the fundamental wave of the frequency f0 as shown in FIG. On the other hand, for frequencies higher than the frequency f0, the filter circuit 150 functions as a normal fourth-order LC filter and can attenuate the harmonic components of the transmission power at the frequency f0.

  The capacitances Cf2 of the capacitors 152 and 156 actually vary with respect to the design value represented by the expression (1), but may be within a range of ± 20% with respect to the design value, and ± 10% If it is in the range, it is preferable. When the actual value of the capacitance Cf2 deviates from the design value represented by the expression (1), the characteristics of the filter circuit 150 deviate from the ideal transformer characteristic with a turns ratio of 1, and the voltage and current gain deviates from 1. And the phase difference between them increases (the power factor deteriorates). If the capacitance Cf2 is within the range of ± 20% with respect to the design value, the efficiency of the filter circuit 150 is reduced, but is included in the usable range, and if within the range of ± 10% with respect to the design value, The characteristic of the filter circuit 150 is a characteristic close to an ideal transformer characteristic with a turns ratio of 1 for the fundamental wave of the frequency f0, and no significant reduction in efficiency occurs.

  On the other hand, for the power transmission device 20, the power transmission unit 700 includes a coil 710 and a capacitor 720. Capacitor 720 is connected in series with coil 710 to form a resonant circuit with coil 710. Capacitor 720 is provided to adjust the resonance frequency of power transmission unit 700.

  Filter circuit 610 includes inductors 612 and 616 and capacitors 614 and 618. Inductors 612 and 616 are provided on one of the power line pairs between power supply unit 600 and power transmission unit 700. In the first embodiment, inductors 612 and 616 are connected in series between terminals T5 and T7. Capacitor 614 is connected between the power line pair between inductors 612 and 616. Capacitor 618 is connected between the power line pair on the power transmission unit 700 side of inductor 616. That is, the inductors 612 and 616 and the capacitors 614 and 618 are provided in the order of the inductor 612, the capacitor 614, the inductor 616, and the capacitor 618 from the power supply unit 600 side.

  Also in the filter circuit 610, the inductance of the inductor 612 is equal to the inductance of the inductor 616. Further, the capacitance of the capacitor 614 is equal to the capacitance of the capacitor 618. Capacitance Cf1 of capacitors 614 and 618 is set to a value represented by the following equation (5).

  Here, Lf1 is the inductance of the inductors 612 and 616. By setting the capacitance Cf1 of the capacitors 614 and 618 based on the equation (5), the filter circuit 610 has a voltage / current gain of 1 for the fundamental wave of the frequency f0, and has a frequency ( For harmonics, etc., it functions as a normal fourth-order LC filter. Hereinafter, this point will be described.

  The input voltage of the filter circuit 610 (voltage between the terminals T5 and T6) is Vfin1, the frequency is f (angular frequency ω = 2πf), and the output voltage of the filter circuit 610 (voltage between the terminals T7 and T8) is Vfout1. Then, the relationship between the input voltage Vfin1 and the output voltage Vfout1 is expressed by the following equation (6).

  Substituting equation (5) into equation (6) yields equation (7) below.

  If ω = ω0 in the equation (7), the following equation (8) is obtained.

  From equation (8), the filter circuit 610 is also equivalent to an ideal transformer with a turns ratio of 1 for the fundamental wave of frequency f0, and the gain is 1 for both voltage and current. On the other hand, for frequencies higher than the frequency f0, the filter circuit 610 functions as a normal fourth-order LC filter and can attenuate the harmonic component of the transmission power at the frequency f0.

  Note that the capacitance Cf1 of the capacitors 614 and 618 may be within a range of ± 20% with respect to the design value, and is preferably within a range of ± 10%, similarly to the filter circuit 150 on the vehicle 10 side. If the capacitance Cf1 is within the range of ± 20% with respect to the design value, the efficiency of the filter circuit 610 is reduced, but is included in the usable range, and if within the range of ± 10% with respect to the design value, The characteristic of the filter circuit 610 is close to the ideal transformer characteristic with a turns ratio of 1 for the fundamental wave of the frequency f0, and the efficiency is not significantly reduced.

  Next, system characteristics of the power transmission system when filter circuits 610 and 150 are inserted into the power transmission device 20 and the vehicle 10 will be described.

  Referring to FIG. 4, the input / output relationship with respect to the fundamental wave component (frequency f0) of power transmission unit 30 constituted by power transmission unit 700 and power reception unit 100 approximates the winding resistance of coils 710 and 110 to zero. Then, it is shown by the following formula (9).

  Here, a is a turn ratio between the coil 710 and the coil 110, and k is a coupling coefficient. L1 and L2 are inductances of the coils 710 and 110, respectively, and Cs1 and Cs2 are capacitances of the capacitors 720 and 120, respectively.

  Therefore, the relationship from the terminals T5 and T6 on the output side of the power supply unit 600 to the terminals T3 and T4 before the rectifying unit 200 is expressed by the following equation (10).

  Note that the turn ratio a = 1. In the formula (9), when the turn ratio a = 1, the formula (10) is the same as the formula (9). Expression (10) indicates that the input / output characteristics of the entire power transmission system are maintained even when the filter circuits 610 and 150 are inserted into the power transmission system. Therefore, even if the filter circuits 610 and 150 are added to the power transmission system, the value of the current flowing through the power supply unit 600 and the rectifying unit 200 is unchanged, and the elements of the power supply unit 600 and the rectifying unit 200 are added by the addition of the filter circuits 610 and 150. There is no need to change the capacity or withstand voltage.

  FIG. 6 is a circuit diagram of the rectifying unit 200 shown in FIG. Referring to FIG. 6, rectifying unit 200 includes a single-phase bridge rectifier circuit including four diodes, and a capacitor 202 provided on the output side. Such a circuit in which a capacitor is provided without providing a choke coil that prevents current change at the subsequent stage of the rectifier circuit is also referred to as a capacitor input type rectifier circuit.

  FIG. 7 is a circuit diagram of power supply unit 600 shown in FIG. Referring to FIG. 7, power supply unit 600 includes a PFC (Power Factor Correction) circuit 602 and an inverter 604. The PFC circuit 602 is a circuit for improving the power factor by suppressing the generation of harmonic current, and various known PFC circuits can be adopted.

  Inverter 604 is a voltage source inverter, and is formed of, for example, a single-phase full-bridge circuit including a smoothing capacitor provided on the DC side and four semiconductor devices. As shown in FIG. 8, the output waveform of the power supply unit 600 configured by such a voltage source inverter 604 is a rectangular wave voltage having the switching frequency f0 (period T0 = 1 / f0) of the voltage source inverter 604. The switching frequency f0 is a frequency (transmission frequency) of power transmitted from the power transmission unit 700 to the power reception unit 100.

  Referring to FIG. 4 again, in the first embodiment, capacitor 720 is connected in series to coil 710 in power transmission unit 700, and capacitor 120 is connected in series to coil 110 in power reception unit 100. Such a circuit configuration is also referred to as an SS system (primary series / secondary series system). In the first embodiment in which the SS system is used, the filter circuit 150 provided in the vehicle 10 is a C-L-C-L type fourth-order LC filter in which the input side is capacitive and the output side is inductive. Consists of. On the other hand, the filter circuit 610 provided in the power transmission device 20 is configured by an LCLC type fourth-order LC filter whose input side is inductive and whose output side is capacitive. The reason why each of the filter circuits 150 and 610 is configured as described above is as follows.

  That is, when the filter circuit 150 provided in the vehicle 10 employs an L-CLC type in which the input side (the power receiving unit 100 side) is inductive, the resonance frequency of the power receiving unit 100 is caused by the inductance of the first-stage inductor. It deviates from the set value f0. Therefore, the filter circuit 150 on the vehicle 10 side is configured by a C-L-C-L type fourth-order LC filter whose input side is capacitive, and the filter circuit 150 does not affect the resonance state of the power receiving unit 100. It is what I did.

In the SS system, Vfout1 = −jx ₀ ^′ × Ifin2 (when the turn ratio a = 1) is derived from the equation (9) for the fundamental wave component. Therefore, in the first embodiment in which the power transmission side is voltage-driven by the voltage source inverter 604, the output of the power transmission unit 30 is equivalently a current source. That is, the input of the rectifying unit 200 of the vehicle 10 is equivalently a current source. In this case, if a choke coil that prevents current change is provided at the subsequent stage of the rectifier circuit, the input current of the rectifier unit 200 is distorted and the input voltage becomes pulsed, which deteriorates the power factor. Therefore, in the first embodiment, as shown in FIG. 6, the rectifying unit 200 is configured by a capacitor input rectifier circuit in which a choke coil is not provided on the output side of the rectifier circuit. As a result, the input voltage of the rectifying unit 200 becomes a rectangular wave having a peak value of the output voltage (DC), and the power factor can be increased as compared with the case where the input voltage is constituted by a choke input type rectifier circuit.

  On the other hand, the filter circuit 610 provided in the power transmission device 20 adopts a C-L-C-L type in which the input side (power supply unit 600 side) is capacitive, and the voltage source voltage source inverter 604 (FIG. 7). A large pulse current flows from the first capacitor to the first capacitor. Therefore, the filter circuit 610 on the power transmission device 20 side is configured by an L-LCLC type fourth-order LC filter whose input side is inductive, and a large pulsed current flows from the power supply unit 600 to the filter circuit 610. It is intended to suppress the flow.

  As described above, according to the first embodiment, in the filter circuit 150, the inductors 154 and 158 can be shared, and the capacitors 152 and 156 can also be shared. Also in the filter circuit 610, the inductors 612 and 616 can be shared, and the capacitors 614 and 618 can be shared. Then, by setting the capacitance Cf2 of the capacitors 152 and 156 based on the formula (1) and setting the capacitance Cf1 of the capacitors 614 and 618 based on the formula (5), the filter circuits 150 and 610 can generate the fundamental wave (frequency For f0), the current / voltage gain is 1, and a wave having a frequency higher than the fundamental wave (such as a harmonic) functions as a normal LC filter. Therefore, according to the first embodiment, it is possible to share the components of the filter circuits 150 and 610 and to suppress changes in system characteristics due to the provision of the filter circuits 150 and 610.

  In addition, the inductances of the inductors 154 and 158 of the filter circuit 150 and the inductances of the inductors 612 and 616 of the filter circuit 610 are made equal, and the capacitances of the capacitors 152 and 156 of the filter circuit 150 and the capacitors 614 and 618 of the filter circuit 610 If the capacitance is made equal, parts can be shared between the filter circuits 150 and 610.

  Further, according to the first embodiment, the filter circuit 150 is configured by the C-L-C-L type fourth-order LC filter whose input side is capacitive, so that the resonance state of the power reception unit 100 by the filter circuit 150 is achieved. Can be avoided.

  Further, according to the first embodiment, since the rectifying unit 200 is configured by the capacitor input rectifier circuit in which the choke coil is not provided immediately after the rectifier circuit, it is possible to suppress the power factor reduction due to the distortion of the input current.

  Further, according to the first embodiment, since the filter circuit 610 is configured by the LC LC type fourth-order LC filter whose input side is inductive, the filter circuit is changed from the voltage source inverter 604 of the power supply unit 600 to the filter circuit. It is possible to suppress a large pulse current from flowing to 610.

[Modification of Embodiment 1]
In the above description, the inductors of the filter circuits 150 and 610 are provided on one side of the power supply line. However, the inductors may be provided on both sides of the power supply line.

  FIG. 9 is a view showing a modification of the filter circuit 150 provided in the vehicle 10. Referring to FIG. 9, filter circuit 150 includes capacitors 152 and 156 and inductors 154A, 154B, 158A and 158B. The inductors 154A and 154B are obtained by dividing the inductor 154 shown in FIG. 4, and the sum of the inductances of the inductors 154A and 154B is the same as the inductance of the inductor 154 shown in FIG. Similarly, inductors 158A and 158B are obtained by dividing inductor 158 shown in FIG. 4, and the sum of the inductances of inductors 158A and 158B is the same as the inductance of inductor 158 shown in FIG.

  The inductances of the inductors 154A and 154B do not necessarily have to be the same. However, by making the inductances of the inductors 154A and 154B the same, the line impedances in the current forward path and the return path become equal, so common mode noise There is an inhibitory effect. The same applies to the inductances of the inductors 158A and 158B.

  FIG. 10 is a diagram illustrating a modification of the filter circuit 610 provided in the power transmission device 20. Referring to FIG. 10, filter circuit 610 includes inductors 612A, 612B, 616A, 616B and capacitors 614, 618. The filter circuit 610 can be described in the same manner as the filter circuit 150 shown in FIG.

[Embodiment 2]
In the second embodiment, a power transmission unit including a power transmission unit and a power reception unit is configured by a so-called SP system (primary series / secondary parallel system).

  FIG. 11 is a circuit diagram of the power transmission system according to the second embodiment. Referring to FIG. 11, the power transmission system in the second embodiment replaces power reception unit 100, filter circuit 150, and rectification unit 200 in the configuration of the power transmission system in the first embodiment shown in FIG. 4. Part 100A, filter circuit 150A, and rectifier 200A.

  Power receiving unit 100 </ b> A includes a coil 110 and a capacitor 122. The capacitor 122 is connected in parallel to the coil 110 to form a resonance circuit with the coil 110. The capacitor 122 is provided to adjust the resonance frequency of the power receiving unit 100A. Note that the Q value indicating the resonance strength of the power receiving unit 100A is preferably 100 or more.

  Filter circuit 150A includes inductors 154 and 158 and capacitors 156 and 160. In this filter circuit 150A, inductors 154 and 158 and capacitors 156 and 160 are provided in the order of inductor 154, capacitor 156, inductor 158, and capacitor 160 from the power receiving unit 100A side. That is, the filter circuit 150A is configured by an LCLC fourth-order LC filter whose input side is inductive and whose output side is capacitive.

  The capacitance of the capacitor 160 is equal to the capacitance of the capacitor 156 (note that as described above, the inductance of the inductor 154 is equal to the inductance of the inductor 158). Capacitance Cf2 of capacitors 156 and 160 is set to a value represented by the above-described equation (1). Thereby, as described above, the filter circuit 150A has a voltage / current gain of 1 for the fundamental wave of the frequency f0 (= ω0 / 2π), and a frequency (such as a harmonic) higher than the frequency f0. Function as a normal fourth-order LC filter.

  Note that the input / output relationship with respect to the fundamental wave component (frequency f0) of the power transmission unit 30A using the SP method can be expressed as the following equation when the winding resistances of the coils 710 and 110 are approximated to zero.

  If the turns ratio a between the coil 710 and the coil 110 is 1, Vfout1 = b × Vfin2, and the SP power transmission unit 30A is equivalent to an ideal transformer with a turn ratio b. Since power supply unit 600 is configured by voltage source inverter 604 (FIG. 7), in this second embodiment in which the SP method is used, the output of power transmission unit 30A is equivalently a voltage source.

  In the second embodiment, the filter circuit 150A provided in the vehicle 10 has an inductive L-C-L-L input side (power receiving unit 100A side) and a capacitive output side (rectifier unit 200A side). It is composed of a C-type fourth-order LC filter. When the C-L-C-L type having a capacitive input side is employed in the filter circuit 150A, the resonance frequency of the power receiving unit 100A is deviated from the set value f0 due to the capacitance of the first-stage capacitor. Therefore, the filter circuit 150A is configured by an L-LCLC type fourth-order LC filter whose input side is inductive, and the resonance state of the power receiving unit 100A is not affected by the filter circuit 150A. .

  FIG. 12 is a circuit diagram of the rectifier 200A shown in FIG. Referring to FIG. 12, rectifying unit 200A further includes a choke coil 204 in the configuration of rectifying unit 200 in the first embodiment shown in FIG. The choke coil 204 is provided between the rectifier circuit and the capacitor 202. Such a circuit in which a choke coil for preventing a current change is provided at the subsequent stage of the rectifier circuit is also referred to as a choke input type rectifier circuit.

  As described above, in the second embodiment in which the SP method is used, the output of the power transmission unit 30A is equivalently a voltage source. That is, the input of the rectifier 200A is equivalently a voltage source. In this case, if the choke coil that prevents the current change is not provided at the subsequent stage of the rectifier circuit, the input current of the rectifier 200A becomes a pulse and the power factor is deteriorated. Therefore, in the second embodiment, as shown in FIG. 12, the rectifier 200A is configured by a choke input rectifier circuit in which a choke coil is provided on the output side of the rectifier circuit. Thereby, the input current of the rectifying unit 200A becomes a rectangular wave having a peak value of the output current (DC), and the power factor can be increased as compared with the case where the capacitor input type rectifier circuit is used.

  As described above, according to the second embodiment, the filter circuit 150A is configured by the LC LC type fourth-order LC filter whose input side is inductive. The influence on the resonance state can be avoided.

  Further, according to the second embodiment, since the rectifying unit 200A is configured by the choke input rectifier circuit in which the choke coil is provided immediately after the rectifier circuit, it is possible to suppress the power factor from being lowered.

[Modification of Embodiment 2]
Referring to FIG. 11 again, in the second embodiment in which the SP method is used, capacitance Cs1 of capacitor 720 of power transmission unit 700 is set to a value represented by the following expression (12), and filter circuit 150A of vehicle 10 When the inductance of the inductor 154 at the first stage is set to Lf2 + L2 (L2 is the self-inductance of the coil 110 of the power receiving unit 100A), it is related to the change in the coupling coefficient k accompanying the relative position change between the power transmitting unit 700 and the power receiving unit 100A. Therefore, the ideal transformer characteristics can be maintained.

  When the capacitance Cs1 of the capacitor 720 is set based on the equation (12), the input / output relationship of the power transmission unit 30A with respect to the fundamental wave component (frequency f0) is expressed as the following equation.

  The winding ratio a between the coil 710 and the coil 110 was 1. Assuming that the inductance of the first stage inductor 154 in the filter circuit 150A of the vehicle 10 is Lf2 + L2, the relationship from the terminals T7 and T8 on the input side of the power transmission unit 30A to the terminals T3 and T4 before the rectifying unit 200A is expressed by the following equation ( 14).

  The above equation (14) indicates that the circuit including the power transmission unit 30A and the filter circuit 150A is equivalent to an ideal transformer having a turn ratio b. Therefore, according to the modification of the second embodiment, the ideal transformer characteristic can be maintained regardless of the change of the coupling coefficient k accompanying the relative position change between the power transmitting unit 700 and the power receiving unit 100A. And harmonic current can be suppressed.

[Embodiment 3]
In the third embodiment, a power transmission unit including a power transmission unit and a power reception unit is configured by a so-called PP system (primary parallel secondary parallel system).

  FIG. 13 is a circuit diagram of the power transmission system according to the third embodiment. Referring to FIG. 13, the power transmission system in the third embodiment replaces power transmission unit 700, filter circuit 610, and power supply unit 600 in the configuration of the power transmission system in the second embodiment shown in FIG. 11. Part 700A, filter circuit 610A, and power supply part 600A.

  Power transmission unit 700 </ b> A includes a coil 710 and a capacitor 722. The capacitor 722 is connected in parallel to the coil 710 and forms a resonance circuit with the coil 710. Capacitor 722 is provided to adjust the resonance frequency of power transmission unit 700A. In addition, it is preferable that Q value which shows the resonance intensity | strength of 700 A of power transmission parts is 100 or more.

  Filter circuit 610 </ b> A includes capacitors 614 and 620 and inductors 612 and 616. In this filter circuit 610A, capacitors 614, 620 and inductors 612, 616 are provided in order of a capacitor 620, an inductor 612, a capacitor 614, and an inductor 616 from the power supply unit 600A side. That is, the filter circuit 610A is configured by a C-L-C-L type fourth-order LC filter in which the input side is capacitive and the output side is inductive.

  The capacitance of the capacitor 620 is equal to the capacitance of the capacitor 614 (note that, as described above, the inductance of the inductor 612 is equal to the inductance of the inductor 616). Capacitance Cf1 of capacitors 614 and 620 is set to a value represented by the above equation (5). Thereby, as described above, the filter circuit 610A has a voltage / current gain of 1 for the fundamental wave of the frequency f0 (= ω0 / 2π) and is higher than the frequency f0 (such as harmonics). Function as a normal fourth-order LC filter.

  The filter circuit 610A is configured by a CLCCL type fourth-order LC filter when the output side (power transmission unit 700A side) is configured to be L-CLCC type to be capacitive. This is because the resonance frequency of the power transmission unit 700A deviates from the set value f0 due to the capacitance of the capacitor in the stage.

  FIG. 14 is a circuit diagram of power supply unit 600A shown in FIG. Referring to FIG. 14, power supply unit 600 </ b> A includes a PFC circuit 602 and a current source inverter 606. The output waveform of the current source inverter 606 is a rectangular wave current having a frequency f0. As the current source inverter 606, various known current source inverters can be employed.

  Referring to FIG. 13 again, in the third embodiment, filter circuit 610A is configured by a C-L-C-L type fourth-order LC filter. Therefore, when the power supply unit is configured by a voltage source inverter, A large pulsed current flows through the capacitor 620 at the first stage of the circuit 610A. Therefore, in the third embodiment, a current source inverter 606 is employed in the power supply unit 600A to suppress the flow of a large pulsed current from the power supply unit 600A to the filter circuit 610A.

  As described above, according to the third embodiment, the filter circuit 610A is configured by the CLCCL type fourth-order LC filter in which the input side is capacitive and the output side is inductive. The influence of the circuit 610A on the resonance state of the power transmission unit 700A can be avoided. Further, since the power supply unit 600A includes the current source inverter 606, it is possible to suppress a large pulsed current from flowing from the power supply unit 600A to the filter circuit 610A.

[Other variations]
In each of the above embodiments, the rectifier 200 (200A) provided in the vehicle 10 includes a single-phase bridge rectifier circuit including four diodes. However, as shown in FIG. The rectifying unit may be configured by a possible single-phase inverter. Thereby, electric power can be supplied from the vehicle 10 to the outside of the vehicle (for example, the power transmission device 20).

  Moreover, in the above, although the case where the power transmission part was SS system, SP system, and PP system was demonstrated, you may comprise a power transmission part by another system. For example, as shown in FIG. 16, a PS system (primary parallel secondary series system) may be adopted. In this case, the vehicle 10 is equipped with a filter circuit 150 composed of a C-L-C-L type fourth-order LC filter, and the power transmission device 20 is equipped with a C-L-C-L type fourth-order LC filter. A power supply unit 600A including a filter circuit 610A and a current source inverter may be employed.

  Further, when a desired resonance frequency can be achieved without providing a capacitor in the power receiving unit and / or the power transmitting unit, as shown in FIG. 17, the power receiving unit may not include a capacitor. As shown in FIG. 6, the power transmission unit may not include a capacitor.

  Note that the configuration shown in the modification of the first embodiment can also be applied to other embodiments.

  The embodiments disclosed this time are also scheduled to be implemented in appropriate combinations. The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  10 vehicle, 20 power transmission device, 30, 30A, 30B power transmission unit, 100, 100A, 100B power reception unit, 110, 710 coil, 120, 122, 152, 156, 160, 202, 614, 618, 620, 720, 722 Capacitor, 150, 150A, 610, 610A Filter circuit, 154, 158, 612, 616 Inductor, 200, 200A, 200B Rectifier, 204 Choke coil, 300 Power storage device, 400 Power generation device, 500 Vehicle ECU, 600, 600A Power supply Part, 602 PFC circuit, 604 inverter, 606 current source inverter, 700, 700A, 700B power transmission part, 800 power supply ECU, 900 external power supply.

Claims (10)

A power receiving unit for receiving power output from the power transmission device in a contactless manner;
A rectifier that rectifies the power received by the power receiver;
A filter circuit provided between the power reception unit and the rectification unit,
The filter circuit is
First and second inductors provided in at least one of a pair of power lines connected between the power reception unit and the rectification unit;
Each of which is connected between the power line pair, and includes first and second capacitors provided alternately with the first and second inductors between the power reception unit and the rectification unit,
The inductance of the first inductor is equal to the inductance of the second inductor,
The capacitance of the first capacitor is equal to the capacitance of the second capacitor;
The power receiving device, wherein the capacitance is set to C≈2 / (L × (2πf) ² ), where L is the inductance and f is the frequency of the power. 2. The power receiving device according to claim 1, wherein, when C0 = 2 / (L × (2πf) ² ), the capacitance is set in a range of 0.9 × C0 <C <1.1 × C0. The power receiving unit
A receiving coil;
A series capacitor connected in series to the power receiving coil,
The first and second inductors and the first and second capacitors are arranged in the order of the first capacitor, the first inductor, the second capacitor, and the second inductor from the power receiving unit side. The power receiving device according to claim 1, wherein the power receiving device is provided. The power receiving unit
A receiving coil;
A parallel capacitor connected in parallel to the power receiving coil,
The first and second inductors and the first and second capacitors are in order of the first inductor, the first capacitor, the second inductor, and the second capacitor from the power receiving unit side. The power receiving device according to claim 1, wherein the power receiving device is provided. The power receiving unit
A receiving coil;
A series capacitor connected in series to the power receiving coil,
The power receiving device according to claim 1, wherein the rectifier includes a capacitor input rectifier circuit. The power receiving unit
A receiving coil;
A parallel capacitor connected in parallel to the power receiving coil,
The power receiving device according to claim 1, wherein the rectifier includes a choke input rectifier circuit. AC power supply,
A power transmission unit for receiving power from the AC power source and transmitting power to the power receiving device in a contactless manner;
A filter circuit provided between the AC power source and the power transmission unit,
The filter circuit is
First and second inductors provided on at least one of a pair of power lines connected between the AC power source and the power transmission unit;
Each of which is connected between the pair of power lines, and includes first and second capacitors provided alternately with the first and second inductors between the AC power source and the power transmission unit,
The inductance of the first inductor is equal to the inductance of the second inductor,
The capacitance of the first capacitor is equal to the capacitance of the second capacitor;
The capacitance is set to C≈2 / (L × (2πf) ² ), where L is the inductance and f is the frequency of the AC power supply. The power transmission device according to claim 7, wherein, when C0 = 2 / (L × (2πf) ² ), the capacitance is set in a range of 0.9 × C0 <C <1.1 × C0. The AC power supply includes an inverter that outputs a rectangular wave voltage,
The first and second inductors and the first and second capacitors are arranged in the order of the first inductor, the first capacitor, the second inductor, and the second capacitor from the AC power supply side. The power transmission device according to claim 7 or 8, which is provided. The power transmission unit
A power transmission coil;
A parallel capacitor connected in parallel to the power transmission coil,
The first and second inductors and the first and second capacitors are arranged in the order of the first capacitor, the first inductor, the second capacitor, and the second inductor from the AC power supply side. Provided,
The power transmission apparatus according to claim 7 or 8, wherein the AC power supply includes a current source inverter.

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