JP6678804B1 - Impedance matching circuit and contactless power supply system having the impedance matching circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impedance matching circuit and a contactless power feeding system having the impedance matching circuit, which dramatically improves the calculation speed of the load impedance and the matching amount required for impedance matching and the matching accuracy. SOLUTION: Voltages at two different points on a transmission line are detected, load impedances are calculated by simultaneous equations generated from the magnitudes of the voltages at the two points, and target impedances are matched from the calculated load impedances. A matching circuit that calculates the reactance amount of the variable reactance element necessary for that purpose and adjusts the impedance of the variable reactance element is provided. [Selection diagram] Fig. 1

Description

  The disclosure of the present specification relates to power transmission between a power source and a circuit including a power transmitting element, and a load and a load impedance of a circuit including a power receiving element disposed in a non-contact manner facing the power transmitting element. The present invention relates to an impedance matching circuit that performs impedance matching and a wireless power supply system having the impedance matching circuit.

  In recent years, for the purpose of improving the convenience of power transmission for charging and the like, a power transmitting side device having a power transmitting element for outputting power in a non-contact manner, and a non-contact receiving of power supplied from the power transmitting side device. A non-contact power supply system including a power receiving side device having the above power receiving element has attracted attention.

  In non-contact power feeding, in order to perform the power transmission with the maximum transmission efficiency without power loss, it is necessary to match the output impedance of the power transmitting side device with the load impedance of the power receiving side device. Particularly, in the case of a high-frequency circuit, reflection occurs due to mismatch between the output impedance and the load impedance, that is, both impedances, and the transmission efficiency is reduced. Therefore, it is necessary to match both impedances.

  For example, the impedance matching circuit is composed of a circuit composed of lumped constants L and C or a distributed constant microstrip, and a circuit composed of lumped constants L and C is connected between the antenna and the amplifier circuit. ing. This suppresses the reflected power loss returning to the power transmission and helps to improve the power transmission efficiency of the entire system (for example, refer to Patent Document 1).

  In addition, an impedance matching circuit is described as a π matching circuit, which is connected between a drive source having a high-frequency signal source and a load, and automatically applies impedance by applying a power supply voltage from a power supply. (For example, see Patent Document 2).

  In this matching circuit, based on the traveling wave component signal and the reflected wave component signal detected by the directional coupler, the phase detection circuit determines the phase difference between the reflected wave component signal and the traveling wave component signal as a reference. To detect. This phase difference is determined by a correction direction determination circuit as to whether or not it has a leading or lagging component at a predetermined angle. The variable capacitance control circuit adjusts the variable capacitance of the capacitor based on the determination result to match the output impedance of the drive source with the load impedance on the output terminal side.

  In another non-contact power transmission system, a matching circuit is provided, and the detection unit detects an AC signal input to the power transmission resonator. Based on the fluctuation of the AC signal detected by the detection unit, the impedance of the power transmission resonator and the output impedance of the power supply are matched by the impedance control unit (for example, see Patent Document 3).

  Further, according to another wireless power transmission system, a matching circuit having a variable reactance element, a traveling-wave / reflected-wave extracting unit for extracting a traveling-wave voltage and a reflected-wave voltage, and extracted by the traveling-wave / reflected-wave extracting unit. A reflection coefficient is calculated from the traveling wave voltage and the reflected wave voltage, and a reflection coefficient calculation unit that calculates the input impedance from the relationship between the reflection coefficient and the impedance of the matching target and the input impedance, from the input impedance. A position determining unit and a control value output unit for calculating a capacitance value distributed to the variable reactance element of the matching circuit and setting a reactance value of the reactance element, wherein a reflection coefficient absolute value is smaller than a predetermined threshold value. If it is larger, change the row used in the matching correction amount table to change the configuration of the matching circuit. A wireless power transmission system during automatic electric traveling in which the load is fed by power from the power source when electromagnetic coupling is performed by the power transmitting antenna and the power receiving antenna through a configuration for automatically matching the impedance. It is disclosed (for example, see Patent Document 4).

JP 2015-56760 A JP 2010-87845 A JP 2012-135117 A JP-A-2005-122555

  However, in Patent Documents 1 to 3, it is necessary to prepare some matching circuits in advance and switch the optimum circuit by a switching circuit. It may take time and effort to combine the optimal matching circuit using the optimal algorithm from the voltage feedback. Since the load impedance to be matched is determined in an unknown state, the circuit is enlarged, and the optimum algorithm may not be secured. Since the transmission-side impedance and the reception-side impedance are not accurately measured, the matching accuracy and the adjustment range are limited, and the impedance matching may not be achieved.

  Further, with respect to Patent Document 4, when changing the configuration of the matching circuit, it is necessary to read data corresponding to the change amount from a predetermined matching correction amount table, and it takes time for processing throughput. there were. In particular, in an environment where processing in a short time is required, such as when power transmission is performed while the moving body is moving, the time required for such processing becomes an important issue. In particular, the amount of correction required for matching differs depending on the load on the power receiving side device. However, since the values of the predetermined matching correction amount table are lists of discrete values, there is no corresponding amount of correction. If not, there is a risk of falling into a so-called infinite loop.

  By the way, since the impedance is a parameter for an AC signal, the impedance is a quotient of a signal voltage and a current, and has two components of amplitude and phase. That is, it is a complex number. Then, since the prior arts described above estimate the load impedance necessary for impedance matching based on the measurement of the complex reflection coefficient, the phase component of the reflection coefficient is affected by phase synchronization, cable length, and the like. There has been a problem that an estimation error is likely to occur and the reliability of the impedance matching accuracy is reduced.

  The disclosure of the present specification is intended to solve the above-described problem, and provides an impedance matching circuit and a impedance matching circuit that dramatically improve the calculation speed and matching accuracy of a load impedance and a matching amount required for impedance matching. It is an object of the present invention to provide a non-contact power supply system having:

  In order to achieve the above object, an impedance matching circuit according to the present disclosure detects a voltage at two different points on a transmission line, and calculates a load impedance by a simultaneous equation generated from the magnitudes of the voltages at the two points. The most main feature is to calculate a reactance amount of the variable reactance element necessary to match the target impedance from the calculated load impedance, and to provide a matching circuit for adjusting the impedance of the variable reactance element. I do.

That is, an impedance for performing impedance matching in power transmission between an output impedance of a circuit including a power transmission power supply and a power transmission element and a load impedance of a circuit including a load and a power reception element arranged to face the power transmission element in a non-contact manner. A matching circuit,
It constitutes the impedance matching circuit, a transmission line path having a predetermined length, a detector for detecting a voltage of the two points at different distances from the load as the first detection voltage and second detection voltage, wherein the two different From a distance between points, the first detection voltage and the second detection voltage, a known incident wave voltage obtained from the power transmission power supply, and a phase constant, a simultaneous equation for estimating a reflection coefficient of the transmission line is generated, A calculation unit that calculates an estimated value of the load impedance from the estimated reflection coefficient and a target impedance for performing the matching ,
In order to match the target impedance for matching between the output impedance to the calculated load impedance, a matching unit having a variable reactance element,
From the calculated load impedance, a reactance amount of the variable reactance element required for the matching is calculated, and an impedance adjustment unit that adjusts the impedance of the variable reactance element based on the calculated reactance amount. Features.

  According to this configuration, the first detection voltage and the second detection voltage are obtained from two different points on the transmission line, the load impedance is calculated by the simultaneous equations, and the reactance amount necessary for matching the target impedance is calculated. It becomes possible.

  In addition, you may make it provide the non-contact electric power feeding system which has the matching circuit concerning the said invention.

  The matching circuit and the non-contact power supply system disclosed in the present specification do not require calculation of load impedance required for impedance matching and specification of a matching amount based on the calculated load impedance in a data table in advance, which is a simple equation. , The processing speed of impedance matching is dramatically improved, and an effect is achieved in that quick power transmission and power supply can be realized.

  Further, since the above equation eliminates the phase component and generates only the amplitude component, the calculation accuracy of the load impedance is dramatically improved, and an efficient and effective matching circuit for power transmission and power supply is provided. This has the effect of realizing it.

FIG. 1 is a diagram showing a block configuration diagram of the impedance matching circuit according to the present embodiment. FIG. 2 is a diagram illustrating a concept of a voltage measurement position on a transmission line in the impedance matching circuit according to the present embodiment. FIG. 3 is a diagram illustrating a block configuration diagram of the wireless power supply system according to the disclosure of the present specification. FIG. 4 is a schematic diagram illustrating an encounter state between a carrier equipped with a power receiving device and a power transmitting device. FIG. 5 is a schematic diagram illustrating an encounter state between a vehicle including a power receiving device and a power transmitting device. 6A and 6B are diagrams illustrating a moving body including a power receiving side device and a power transmitting side device provided in a track, and FIG. 6A is a side view illustrating a correspondence between the moving body and the power transmitting side device. (B) is a top view of a power transmission side device arranged in a track.

  Hereinafter, in the present embodiment, a matching circuit including a primary coil as a power transmitting element and a secondary coil as a power receiving element will be described as an example.However, the matching circuit according to the present disclosure includes magnetic field coupling, electric field coupling, Furthermore, any of the radiation type power supply methods is applicable, and the shapes of the power transmitting element and the power receiving element are not limited to the coils.

<Embodiment of impedance matching circuit>
Referring to FIG. 1, reference numeral 200 denotes an impedance matching circuit according to the second embodiment. Similarly to the impedance matching circuit 200 according to the first embodiment, the impedance matching circuit 200 performs impedance matching by a simple calculation process. The load impedance has a transmission line having a predetermined length, and is calculated from voltages at two different points on the transmission line. That is, in the case of high frequency, on a transmission line such as a long coaxial cable or a parallel conducting wire, the voltage is constant at any position unless reflected waves are present, but the voltage is not constant between the power transmission side and the power reception side. When a reflected wave is generated due to the matching, the presence of the standing wave causes a mismatch between the voltage amplitude values at two different points on the transmission line as a distributed constant circuit. The present embodiment utilizes this property.

Impedance matching circuit 200, as described later, the load impedance Z _L of the power receiving object serving as the load, the matching impedance (i.e., the target impedance) is determined by the matching unit 204.

Detection unit 201, as shown in Figure 2, two arbitrary different points on the transmission line W, i.e., the voltage of the two points of a point from the load and a point at a distance of X ₁ from the load at a distance of X ₂ Is detected. The first voltage detecting unit 201a detects a voltage of a point at a distance of X _1, the second voltage detecting unit 201b are respectively detected in real time the voltage of the point at a distance of X2.

The voltages at the two points detected by the detection unit 201 are subjected to analog-to-digital conversion processing by an AD conversion unit 202a of a signal processing unit 202, and then calculation for estimation of load impedance is executed by a calculation unit 202b. Here, _{V 2} the voltage of the voltage detected by _{X 1} is detected by _V 1, _{X 2,} the incident wave voltage _{V i,} the reflection coefficient of a transmission line gamma _L, the phase constant beta, _{X 1} from the load the reflection coefficient of a point away ^Γ _L -2βX1, when the reflection coefficient of the _{X 2} away point from the load and ^Γ _L -2βX2, holds the following two formulas.

Then, the incident wave voltage V _i is known, from the general formula of the phase constant beta, the two equations in Equation 1, is established as a system of equations for estimating the reflection coefficient gamma _L of the transmission line. By the way, assuming that the load impedance is Z _L and the target impedance is Z ₀ , the following equation is established. That is, it is possible on the basis of a simultaneous equation by detecting the 2 expression in Equation 1 of the voltage at two points, to estimate the load impedance Z _L.

Then, the estimated value of the load impedance Z _L at the calculation section 202b is calculated, the circuit elements to match the target impedance Z ₀ is calculated.

  The calculated matching amount is first converted into an analog signal by the DA converter 203a in the adjuster 203. The converted matching amount is distributed to each capacitance value of each of the variable capacitors Cx, Cy, and Cz of the T-type circuit (or L-type or π-type) constituting the matching unit 204. Each capacitance value can be easily calculated if the total amount of the respective variable capacitors Cx, Cy, Cz is the matching amount, and if the voltage value and the current value are known.

  The adjusting unit 203 sets a control voltage value according to the matching amount, and via the first driving unit 203b, the second driving unit 203c, and the third driving unit 203d based on the control voltage value corresponding to each of the capacitance values. Then, the first motor 203e, the second motor 203f, and the third motor 203g connected to the variable capacitors Cx, Cy, and Cz of the matching unit 204 are energized to perform impedance matching processing.

With the above configuration, the impedance matching can be performed by a simple calculation process. For example, a data table indicating the relationship between the voltage at an arbitrary point and the control value as described above is set in advance, and the impedance matching process is performed. In each case, processing such as reading the data table becomes unnecessary. That is, since complicated processing for reading the data table can be eliminated, impedance matching can be performed by an analytical method with a small number of procedures, thereby improving calculation accuracy and throughput. In the present embodiment, the load impedance Z any two points in the estimation of the _{L (X 1,} X ₂₎ has been configured to detect the voltage of the point to be detected, may be three or more points .

<Embodiment of non-contact power supply system>
Hereinafter, a wireless power supply system using the matching circuit according to the present disclosure will be described with reference to FIG. The present embodiment exemplarily shows one embodiment of a non-contact power supply system, and the non-contact power supply system according to the disclosure of the present specification is not limited to this embodiment.

  Referring to FIG. 3, reference numeral 1 denotes a wireless power supply system. The non-contact power supply system 1 includes a charging circuit unit 2, a power transmission unit 3, a power transmission head unit 4, a power reception head unit 5, and a power reception unit 6. The charging circuit unit 2, the power transmission unit 3, and the power transmission head unit 4 configure a power transmission side device A, and the power reception head unit 5 and the power reception unit 6 configure a power reception side device B. The power transmitting side device A and the power receiving side device B are separately provided in a state separated from each other.

  The charging circuit unit 2 of the power transmission side device A includes a power transmission side capacitor 9 that is charged via a power transmission side rectifier circuit 8 by a power supply 7 (transmission power supply) having a standard voltage of 100/200 V AC at a frequency of 50 Hz or 60 Hz, for example. It is provided as a power transmission side buffer unit. The power transmission side capacitor 9 is connected so as to receive power supply from the power supply 7, and is always charged when the power supply 7 is energized. The power transmission side capacitor 9 is connected to a power supply circuit 12 constituting the power transmission unit 3. The term “power supply” is used synonymously with “charge” in the following description.

  The power transmission unit 3 includes a power supply circuit 12 connected to the power supply 7. The power supply circuit 12 includes a charge control unit 10 as a charge control circuit, an oscillation circuit 13 forming an inverter circuit, and a power transmission side control circuit unit 16. The power supply circuit 12 is provided with a power transmission side control circuit section 16 to which a pilot lamp 15 is connected. The power transmission side control circuit section 16 turns on the pilot lamp 15 when receiving the power supply signal S1 from the communication circuit 17 described later.

  The power transmission head unit 4 includes a communication circuit 17 and a primary coil 18. The communication circuit 17 controls the control signal S1 as a communication medium (radio wave, light, sound wave, ultraviolet light, infrared light, or heat wave) from a communication control unit 20 described later. Is to receive. The primary coil 18 is connected to receive a current from the drive circuit 14 to generate a magnetic field.

  The power receiving head unit 5 of the power receiving side device B includes a power receiving side rectifier circuit 19 and a communication control unit 20. The power receiving side rectifier circuit 19 has a secondary coil 19 a that receives power transmission from the primary coil 18 via the impedance matching circuit 200 by electromagnetic field coupling in the electromagnetic field coupling unit. The communication control unit 20 has a transmitting unit (not shown) that sends the control signal S1 to the communication circuit 17. The impedance matching circuit 200 is provided to automatically match the impedance between the power supply and the circuit side of the primary coil 18 by a mechanism described later. The coil of the impedance matching circuit 200, the primary coil 18 and the secondary coil 19a are all formed of a litz wire to increase a Q factor (Quality Factor).

  The power receiving unit 6 includes a control detection circuit 22 and a power receiving side control circuit unit 23, and sends a current from the power receiving side rectification circuit 19 to the control detection circuit 22. The power receiving side control circuit unit 23 is connected to transmit the detection signal S3 from the control detection circuit 22 to the communication control unit 20. The control detection circuit 22 is connected to a power receiving side capacitor 24 as a power receiving target. The power receiving side capacitor 24 constitutes the power storage unit 11 and is charged with the combined power.

  Further, the impedance matching circuit 200 is provided between the power transmission power supply 7 and the primary coil 18. The impedance matching circuit 200 may be provided between the secondary coil 19a and the load.

  FIG. 4 is a diagram in which the non-contact power supply system 1 is applied to a moving body (guided carrier) 25. The power transmission side device A is housed in a power transmission casing 26 and fixed to a stationary member 27, and the power reception side device B is housed in a power reception casing 28 and mounted on a moving body 25 running on floors W inside and outside a factory and inside and outside a warehouse. Is done.

  The power receiving side capacitor 24, which is a power receiving target, is provided on the moving body 25, and is used for driving a drive motor (not shown) for driving wheels to be described later and a steering motor 34 provided on the left and right sides of the steering wheel 33. . The moving body 25 is used for unmanned operation for transporting various tools, parts, products (not shown), and the like placed in factories and warehouses by traveling on the floor surface W. Note that the power transmitting side device A may be fixed to a stationary member 27 described later, and the power receiving side device B may be similarly mounted on the moving body 25 by retrofitting.

  The moving body 25 has a rectangular chassis 30 provided with wheels 29 at four corners, and the chassis 30 is provided with a drive control unit 32 for connecting left and right electromagnetic sensors 31a and 31b. The drive control unit 32 is configured to receive power from the power receiving side capacitor 24 via the output control unit 32a. A derivative 35 made of, for example, aluminum tape is adhered to the floor surface W in a closed loop along a predetermined track. When the moving body 25 travels, the driving of the drive motor and the steering motor 34 is controlled via the drive control unit 32 by output signals from the left and right electromagnetic sensors 31a and 31b.

  When the moving body 25 travels, the moving body 25 approaches the stationary member 27 and stops, and the power transmission casing 26 approaches the power receiving casing 28 with a small gap G.

  Accordingly, the secondary coil 19a of the power receiving head unit 5 is positioned so as to face the primary coil 18 of the power transmitting head unit 4, and the communication circuit 17 is positioned so as to correspond to the transmitting unit of the communication control unit 20. At this time, the control detection circuit 22 detects the current value of the power receiving side capacitor 24, and when the threshold level of the current value is less than a predetermined value, the communication control unit 20 is operated by the power receiving side control circuit unit 23, and the communication control unit 20 The communication circuit 17 is operated by the control signal S1 from the power supply circuit 12, and the charging control unit 10 is operated via the power transmission side control circuit unit 16 of the power supply circuit 12.

  As a result, the pilot lamp 15 is turned on, and the power from the power transmission side rectifier circuit 8 is transmitted to the charging control unit 10 of the power supply circuit 12, and at the same time, the power stored in the power transmission side capacitor 9 by the power supply 7 is charged. Sent to 10. The power from the power transmission-side rectifier circuit 8 and the power stored in the power transmission-side capacitor 9 are converted into high-frequency power of the combined power added by the charging control unit 10 via the oscillation circuit 13 and the drive circuit 14 to the primary coil 18. To excite the secondary coil 19a.

  That is, electromagnetic coupling occurs between the primary coil 18 and the secondary coil 19a due to an electromagnetic induction phenomenon, and power is transmitted from the primary coil 18 to the secondary coil 19a. At this time, the power from the secondary coil 19a generates a rectified DC current via the power receiving side rectifier circuit 19, and flows through the power receiving side capacitor 24 from the control detection circuit 22 to be charged.

  When the charging amount of the power receiving side capacitor 24 becomes full and charging is completed, the control detection circuit 22 detects the threshold level of the current value. Accordingly, the power receiving side control circuit unit 23 operates the power transmitting side control circuit unit 16 via the communication control unit 20 and the communication circuit 17, turns off the pilot lamp 15, and sends a stop signal S4 to the charging control unit 10. Then, the power transmission to the oscillation circuit 13 is stopped.

  When the charged amount of the power receiving side capacitor 24 becomes full, power is supplied from the power receiving side capacitor 24 via the output control unit 32a of the drive control unit 32 of the moving body 25, and the drive motor of the drive wheel and the steering wheel 33 are driven. Activated, the guided carrier 25 travels on the floor W along the conductor 35 detected by the left and right electromagnetic sensors 31a and 31b to carry tools and parts.

  FIG. 5 is a diagram in which the non-contact power supply system 1 is applied to a vehicle 47 such as a passenger car. With application to the vehicle 47, a power receiving side battery 48 having a capacity of, for example, 12 V / 23Ah × 2 series is provided as a power receiving target instead of the power receiving side capacitor 24 of the power receiving side device B. The power receiving side battery 48 is a normal battery installed in the hood 49 of the vehicle 47.

  In this case, the power transmitting device A is fixed to the stationary member 27, the power receiving device B is mounted on the vehicle 47, and the power receiving battery 48 is used for starting and driving an engine (not shown) mounted on the vehicle 47. .

  When the power receiving side battery 48 is charged, the vehicle 47 approaches the stationary member 27 and stops, and the power transmission casing 26 is made to correspond to the power reception casing 28 by positioning. As a result, the communication control unit 20 operates, the communication circuit 17 is operated by the control signal S1, and the DC current from the power receiving rectifier circuit 19 supplies power to the power receiving battery 48 via the control detection circuit 22.

  In addition, since the power transmission side device A can be fixed to the stationary member 27 or the power reception side device B can be mounted on the vehicle 47, each of the power transmission side device A and the power reception side device B can be individually dealt with. Can be manufactured and sold.

  In addition, instead of the power transmission side capacitor 9 in the charging circuit section 2, a small and small capacity power transmission side battery may be provided as the power transmission side buffer section. Since the power transmission side battery may be a small-capacity small battery instead of a large-capacity large battery, it contributes to weight reduction and cost reduction of the non-contact power supply system 1. In consideration of this viewpoint, the power transmission side battery may be provided instead of the power transmission side capacitor 9. When a power transmitting battery is provided in place of the power transmitting capacitor 9, a power receiving battery may be provided instead of the power receiving capacitor 24.

  FIG. 6 is a diagram illustrating a moving body (vehicle) 25 including a power receiving side device B and a power transmitting side device A provided in a track. The power transmitting device A is embedded in a track 200A on the ground on which the moving body 25 travels (for example, in a paved road), and the power receiving device B is attached to the moving body 25. As described above, when the primary coil is energized from the power supply 7 (omitted in FIG. 6) while the moving body 25 such as a vehicle is running, electromagnetic coupling is performed when the primary coil 18 encounters the secondary coil 19a from the circuit side. Power is transmitted from the circuit side of the primary coil 18 to the circuit side of the secondary coil 19a to supply power to the power receiving target.

  The primary coil 18 of the power transmitting side device embedded in the track 200A has a horizontally long elliptical shape formed by two linear portions arranged in parallel and an arc-shaped portion connecting both ends of the linear portion. The primary coils 18 are arranged at predetermined intervals along the traveling direction Rm of the track 200A. In addition, for the purpose of preventing the magnetic diffusion between the primary coil 18 and the secondary coil 19a and improving the coupling coefficient, a hard magnetic material such as ferrite is formed below the primary coil 18 of the power transmission side device in the track 200A. A magnetic flux collecting plate (not shown) is arranged in close proximity to the primary coil 18.

  Since the primary coils 18 have a horizontally long elliptical shape, a large number of primary coils 18 are laid horizontally at predetermined intervals along the traveling direction Rm of the track 200A, so that the laying distance per single primary coil 18 is secured. And the primary coils 18 can be arranged over long distances with a small number of primary coils. In this case, since the impedance matching circuit 200 having the coil is located within the range of the primary coil 18, the magnetic flux of the impedance matching circuit 200 for the primary coil 18 can be efficiently transmitted without leaking to the outside.

  The adjacent primary coils 18 are connected to each other by a wiring (corresponding to a coupling unit) via a switching element 200B (corresponding to a switching unit). The distance between the adjacent primary coils 18, that is, the distance between the front end of one primary coil 18 and the rear end of the other primary coil 18 is, for example, an ellipse of the primary coil 18 along the traveling direction of the moving body 25. Set to 1/2 to 2 times the size. However, the separation distance can be set as desired in accordance with the arrangement state of the primary coil 18, the laying state of the track 200A, the use environment, and the like.

  When the primary coil 18 and the secondary coil 19a are encountered during traveling of the moving body 25, the proximity sensor 200C (corresponding to a proximity detection unit) detects the encounter between the primary coil 18 and the secondary coil 19a, so that the switching element 200B operates and the track 200A. Of the primary coils 18 adjacent to each other in the traveling direction Rm are set to be switched from one to the other.

  As described above, as the moving body 25 during traveling moves in the traveling direction Rm, the secondary coil 19a is continuously resonated every time the secondary coil 19a sequentially encounters many adjacent primary coils 18. As a result, continuous power supply during traveling of the moving body 25 becomes possible.

  Specifically, the power receiving side device B including the impedance matching circuit 200 and the secondary coil 19a is mounted on the back surface side of the vehicle body 25a of the moving body 25 via a mounting plate.

  The power receiving side capacitor 24, which is a power receiving object, is connected to, for example, a battery cell 24A for charging disposed in the hood of the automobile, and drives a starter of the automobile, a drive motor for an air conditioning compressor, or various electric components (not shown). )).

200 impedance matching circuit 201 detection unit 202 signal processing unit 203 adjustment unit 204 matching unit

Claims (8)

An impedance matching circuit that performs impedance matching in power transmission between an output impedance of a circuit including a power transmitting power supply and a power transmitting element, and a load impedance of a circuit including a load and a power receiving element disposed in a non-contact manner facing the power transmitting element. And
A detecting unit that configures the impedance matching circuit and detects voltages at two points at different distances from the load on a transmission line having a predetermined length as a first detection voltage and a second detection voltage;
A simultaneous equation for estimating the reflection coefficient of the transmission line from the distance between the two different points, the first detection voltage and the second detection voltage, a known incident wave voltage obtained from the power transmission power supply, and a phase constant. A calculation unit that generates and calculates an estimated value of the load impedance from the estimated reflection coefficient and a target impedance for performing the matching ,
In order to match the target impedance for matching between the output impedance to the calculated load impedance, a matching unit having a variable reactance element,
From the calculated load impedance, an impedance adjustment unit that calculates the reactance amount of the variable reactance element necessary for the matching, and adjusts the impedance of the variable reactance element based on the calculated reactance amount,
An impedance matching circuit comprising: A power transmitting side device including at least a power transmitting power source and a power transmitting element, and a power receiving side device including a load including at least a power receiving target and a power receiving element arranged in a non-contact manner facing the power transmitting element; A non-contact power supply system having an impedance matching circuit that performs impedance matching in power transmission between an output impedance and a load impedance of the power receiving side device,
A detecting unit that configures the impedance matching circuit and detects voltages at two points at different distances from the load on a transmission line having a predetermined length as a first detection voltage and a second detection voltage;
A simultaneous equation for estimating the reflection coefficient of the transmission line from the distance between the two different points, the first detection voltage and the second detection voltage, a known incident wave voltage obtained from the power transmission power supply, and a phase constant. A calculation unit that generates and calculates an estimated value of the load impedance from the estimated reflection coefficient and a target impedance for performing the matching ,
In order to match the target impedance for matching between the output impedance to the calculated load impedance, a matching unit having a variable reactance element,
From the calculated load impedance, an impedance adjustment unit that calculates the reactance amount of the variable reactance element necessary for the matching, and adjusts the impedance of the variable reactance element based on the calculated reactance amount,
Has,
The power transmission side device is provided with a power transmission side buffer unit that is always charged when energized by the power transmission power source, and at the time of the power transmission, the power from the power transmission power source and the power from the power transmission side buffer unit are used. A non-contact power supply system, wherein power is supplied to a power receiving target of a power receiving side device.   The power transmission side buffer unit is at least one of a power transmission side capacitor and a power transmission side battery, and the power reception target is provided as at least one of a power reception side capacitor and a power reception side battery. The wireless power supply system according to claim 2, wherein   The power transmission-side device is fixed to a stationary member, the power reception-side device is mounted on an induction-type carrier that travels on a predetermined floor, and the power-receiving object is provided for driving the induction-type carrier. The wireless power supply system according to claim 2, wherein   The wireless power supply system according to claim 2, wherein the power transmission side device is fixed to a stationary member, the power reception side device is mounted on a vehicle, and the power receiving target is applied to drive the vehicle. .   The power transmitting side device is provided in a track on which a moving body travels, and the power receiving side device is attached to the moving body, and is configured to perform the power transmission when the moving body travels. The wireless power supply system according to claim 2, wherein   The power transmitting element of the power transmitting side device provided in the track has a horizontally long elliptical shape in which two linear portions arranged in parallel and an arc portion connecting both ends of the linear portion are integrated. The wireless power supply system according to claim 6, wherein a plurality of the power transmission elements are arranged on the track at predetermined intervals.   In the track, a plurality of the power transmission elements are laid, and the plurality of power transmission elements are each a proximity detection unit that detects the proximity of the moving body, a connection unit that connects mutually adjacent power transmission elements, The body moves from the position where the power transmitting element and the power receiving element are arranged to face each other to the side of the power transmitting element adjacent to the power transmitting element, and the proximity detection unit of the adjacent power transmitting element detects the proximity of the moving body. And a switching unit configured to switch the power transmission element to be energized to the power transmission element adjacent to each other by an operation of a switching element interposed in the connection unit upon detection. 7. The non-contact power supply system according to 7.

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