WO2012157115A1

WO2012157115A1 - Power reception apparatus, vehicle provided therewith, power feeding equipment, and power feeding system

Info

Publication number: WO2012157115A1
Application number: PCT/JP2011/061550
Authority: WO
Inventors: 達中村; 真士市川
Original assignee: トヨタ自動車株式会社
Priority date: 2011-05-19
Filing date: 2011-05-19
Publication date: 2012-11-22

Abstract

An ECU (350) first adjusts the resonance frequency of a resonance coil (210) to match the power supply frequency by controlling a variable capacitor (220), and after adjusting the resonance frequency, adjusts the gap between the resonance coil (210) and an electromagnetic induction coil (230) by controlling a coil-gap changing apparatus (240). Then the ECU (350) adjusts the resonance frequency of the resonance coil (210) in a state wherein peaks of a frequency spectrum of the power-receiving state, which will change with the gap between the coils, will become one.

Description

Power receiving device, vehicle including the same, power supply facility, and power supply system

The present invention relates to a power receiving device and a vehicle including the power receiving device, a power feeding facility, and a power feeding system. The present invention relates to a power receiving device, a vehicle including the power receiving system, and a power feeding facility in a power feeding system that transmits power in a contactless manner.

As a power transmission method, wireless power transmission (contactless power transmission) that does not use a power cord or a power transmission cable has attracted attention in recent years. As this wireless power transmission technology, three technologies known as power transmission using electromagnetic induction, power transmission using microwaves, and power transmission using a resonance method are known.

Among them, the resonance method is a non-contact power transmission technique in which a pair of resonators (for example, a pair of resonance coils) are resonated in an electromagnetic field (near field) and transmitted through the electromagnetic field. It is also possible to transmit power over a long distance (for example, several meters).

Japanese Patent Laying-Open No. 2010-63245 (Patent Document 1) discloses a non-contact power feeding apparatus using such a resonance method. This non-contact power feeding device has the same resonance frequency as a resonance element (resonance coil) having a variable mechanism for changing the resonance frequency discretely or continuously, an excitation element (electromagnetic induction coil) electromagnetically coupled to the resonance element. An alternating current power source for applying an alternating current having a frequency to the excitation element. Then, the resonance frequency of the power supply source is changed by the variable mechanism according to the specific resonance frequency of the power supply destination, and power is selectively supplied to power supply destinations having different resonance frequencies. According to this non-contact power supply device, power can be selectively supplied to a specific power supply destination (see Patent Document 1).

JP 2010-63245 A JP 2010-239769 A JP 2010-141976 A JP 2010-124522 A

When the interval between the resonance coil and the electromagnetic induction coil (coil interval) changes, the impedance of the resonance system composed of the power transmission unit on the power supply facility side and the power reception unit on the power reception device side changes. Therefore, the impedance of the resonance system can be adjusted to an appropriate value by changing the coil interval. On the other hand, the change in the impedance of the resonance system affects the frequency characteristics of the resonance system, and thus affects the adjustment of the resonance frequency of the resonance coil. The adjustment of the resonance frequency of the resonance coil is desired to be as easy as possible. However, the above publication does not particularly consider this point.

Therefore, an object of the present invention is to facilitate adjustment of the resonance frequency of the resonance coil.

According to this invention, the power receiving device is a power receiving device that receives power from a power supply facility including a power transmission coil in a non-contact manner, the power receiving coil, the electromagnetic induction coil, the first and second changing devices, and the control Device. The power receiving coil is for receiving power from the power transmitting coil in a non-contact manner by resonating with the power transmitting coil via an electromagnetic field. The electromagnetic induction coil is for taking out the electric power received by the power receiving coil by electromagnetic induction. The first changing device is for changing the resonance frequency of the power receiving coil. The second changing device is for changing the coil interval between the power receiving coil and the electromagnetic induction coil. The control device first adjusts the resonance frequency to a predetermined frequency by controlling the first changing device, and adjusts the coil interval by controlling the second changing device after adjusting the resonance frequency. Here, the control device adjusts the resonance frequency in a state where there is one peak in the frequency spectrum of the power reception state that changes depending on the coil interval.

Preferably, the control device adjusts the resonance frequency in a state where the coil interval is the narrowest within the adjustable range of the coil interval.

Preferably, the control device adjusts the coil interval by changing the coil interval in a direction in which the coil interval increases.

Preferably, the control device stops the output to the electric load connected to the power receiving device when the resonance frequency cannot be adjusted to a predetermined frequency within the adjustable range of the resonance frequency.

Preferably, the control device stops the output to the electric load connected to the power receiving device when the adjustment of the coil interval is not completed within the adjustable range of the coil interval.

More preferably, the control device outputs an alarm when the output to the electric load is stopped.
Preferably, the first changing device includes a variable capacitor connected to the power receiving coil.

According to the invention, the vehicle includes any one of the power receiving devices described above.
Further, according to the present invention, the power supply facility is a power supply facility that supplies power to a power receiving device including a power receiving coil in a non-contact manner, the power transmitting coil, the power supply device, the electromagnetic induction coil, the first and the second. A change device and a control device. The power transmission coil resonates with the power reception coil via an electromagnetic field to transmit power to the power reception coil in a contactless manner. The power supply device generates power having a predetermined frequency. The electromagnetic induction coil receives electric power from the power supply device and supplies the electric power to the power transmission coil by electromagnetic induction. The first changing device is for changing the resonance frequency of the power transmission coil. The second changing device is for changing the coil interval between the power transmission coil and the electromagnetic induction coil. The control device first adjusts the resonance frequency to a predetermined frequency by controlling the first changing device, and adjusts the coil interval by controlling the second changing device after adjusting the resonance frequency. Here, the control device adjusts the resonance frequency in a state where the peak of the frequency spectrum of the power reception status of the power reception device, which varies depending on the coil interval, becomes one.

Preferably, the control device stops the power supply device when the resonance frequency cannot be adjusted to a predetermined frequency in the adjustable range of the resonance frequency.

Preferably, the control device stops the power supply device when the adjustment of the coil interval is not completed within the adjustable range of the coil interval.

More preferably, the control device outputs an alarm when the power supply device is stopped.
Preferably, the first changing device includes a variable capacitor connected to the power transmission coil.

According to the present invention, the power supply system includes a power supply device, a first electromagnetic induction coil, a power transmission coil, a power reception coil, a second electromagnetic induction coil, and first and second frequency changes. A device, first and second interval changing devices, and a control device; The power supply device generates power having a predetermined frequency. The first electromagnetic induction coil receives electric power from the power supply device and supplies electric power by electromagnetic induction. The power transmission coil is supplied with electric power from the first electromagnetic induction coil. The power receiving coil is for receiving power from the power transmitting coil in a non-contact manner by resonating with the power transmitting coil via an electromagnetic field. The second electromagnetic induction coil is for taking out the electric power received by the power receiving coil by electromagnetic induction. The first frequency changing device is for changing the first resonance frequency indicating the resonance frequency of the power transmission coil. The second frequency changing device is for changing the second resonance frequency indicating the resonance frequency of the power receiving coil. The first interval changing device is for changing the first coil interval indicating the coil interval between the power transmission coil and the first electromagnetic induction coil. The second interval changing device is for changing the second coil interval indicating the coil interval between the power receiving coil and the second electromagnetic induction coil. The control device first adjusts the first and second resonance frequencies to a predetermined frequency by controlling the first and second frequency changing devices, and after adjusting the first and second resonance frequencies, the first and second resonance frequencies are adjusted. The first and second coil intervals are adjusted by controlling the second interval changing device. Here, the control device adjusts the first and second resonance frequencies in a state where there is one peak in the frequency spectrum of the power reception state that changes depending on the first and second coil intervals.

Preferably, the control device sets the first and second resonance frequencies in a state in which the first and second coil intervals are the narrowest in the adjustable range of the first coil interval and the adjustable range of the second coil interval, respectively. Adjust.

In the present invention, the resonance frequency is first adjusted to a predetermined frequency, and after the resonance frequency is adjusted, the coil interval between the power receiving coil and the electromagnetic induction coil is adjusted. Here, in the power transmission using the resonance method, the frequency characteristic of the power reception situation changes depending on the coil interval, and the frequency spectrum indicating the frequency dependency of the power reception situation has one peak when the coil interval is narrow, Two peaks appear as the coil spacing increases. Therefore, in the present invention, the resonance frequency is adjusted in a state where the peak of the frequency spectrum of the power reception state that changes depending on the coil interval becomes one. Therefore, according to the present invention, the resonance frequency of the resonance coil can be easily adjusted.

It is a functional block diagram which shows the whole structure of the electric power feeding system by embodiment of this invention. It is the equivalent circuit schematic of the part regarding the power transmission by the resonance method. It is the figure which showed the change of the frequency characteristic of the receiving condition in a vehicle when changing a variable capacitor. It is the figure which showed the change of the frequency characteristic of the receiving condition in a vehicle when changing the coil space | interval of a resonance coil and an electromagnetic induction coil. It is the figure which showed the relationship between the charging current and charging voltage to an electrical storage apparatus. It is a 1st flowchart for demonstrating the procedure of the adjustment process of a variable capacitor and a coil space | interval variable apparatus. It is a 2nd flowchart for demonstrating the procedure of the adjustment process of a variable capacitor and a coil space | interval variable apparatus. It is a flowchart for demonstrating the process sequence of the stop sequence shown to FIG. It is the figure which showed the change of the frequency characteristic of reflected electric power when changing a variable capacitor.

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.

FIG. 1 is a functional block diagram showing an overall configuration of a power feeding system according to an embodiment of the present invention. Referring to FIG. 1, the power supply system includes a power supply facility 100 and a vehicle 200 as a power receiving device.

The power supply facility 100 includes a high frequency power supply device 110, a power sensor 115, a coaxial cable 120, an electromagnetic induction coil 130, a resonance coil 140, a variable capacitor 150, and a coil interval variable device 160. The power supply facility 100 further includes a communication device 170 and an ECU (Electronic Control Unit) 190.

The high frequency power supply device 110 generates predetermined high frequency power and outputs it to the coaxial cable 120. For example, the high frequency power supply device 110 converts electric power received from the system power supply into high frequency electric power and outputs it to the coaxial cable 120. Note that the frequency of the high frequency power generated by the high frequency power supply device 110 is set to a predetermined value in the range of 1 M to several tens MHz, for example.

The power sensor 115 detects the reflected power and the traveling wave power in the high frequency power supply device 110 and outputs each detected value to the ECU 190. The reflected power is the power that is returned from the high frequency power supply device 110 after the power output from the high frequency power supply device 110 is reflected. The traveling wave power is power output from the high frequency power supply device 110. As the power sensor 115, various known sensors capable of detecting reflected power and traveling wave power in the power supply device can be used.

The electromagnetic induction coil 130 can be magnetically coupled to the resonance coil 140 by electromagnetic induction coupling, and supplies high frequency power supplied from the high frequency power supply device 110 via the coaxial cable 120 to the resonance coil 140 by electromagnetic induction. For example, the electromagnetic induction coil 130 is disposed so that the central axis thereof coincides with the resonance coil 140.

The resonance coil 140 is supplied with electric power from the electromagnetic induction coil 130 by electromagnetic induction. The resonance coil 140 transmits power to the vehicle 200 in a non-contact manner by resonating with the resonance coil 210 mounted on the vehicle 200 via an electromagnetic field. It should be noted that resonance coil 140 has an appropriate coil diameter and number of turns so that the Q value is large (for example, Q> 100) and the degree of coupling κ is small based on the distance from resonance coil 210 of vehicle 200, the resonance frequency, and the like. Is set. The power transmission by resonance is a power transmission technique different from electromagnetic induction designed so that the Q value is small and the coupling degree κ is large.

The variable capacitor 150 is provided to change the resonance frequency of the resonance coil 140, and is connected between both ends of the resonance coil 140, for example. Variable capacitor 150 can change its capacity in accordance with a command received from ECU 190, and can change the resonance frequency of resonance coil 140 according to the change in capacity.

The coil interval varying device 160 is an interval between the electromagnetic induction coil 130 and the resonance coil 140 (hereinafter simply referred to as “coil interval”. In other words, hereinafter, the “coil interval” is the interval between the resonance coil and the electromagnetic induction coil. Is a device for changing. As an example, the coil interval varying device 160 is constituted by a screw-type rod-shaped instrument, and by rotating the rod-shaped instrument, the position of the electromagnetic induction coil 130 with respect to the resonance coil 140 can be changed along the central axis of the coil. it can. The configuration of the coil interval varying device 160 is not limited to this example, and any configuration may be used as long as the coil interval can be changed.

The coil interval varying device 160 is for adjusting the impedance of the resonance system composed of the electromagnetic induction coil 130 and the resonance coil 140, and the resonance coil 210 and the electromagnetic induction coil 230 (described later) mounted on the vehicle 200. That is, when the coil interval changes, the resonance impedance changes. In order to realize high-efficiency power transmission, it is necessary to match the input impedance of the resonance system with the output impedance of the high-frequency power supply device 110. By changing the coil interval using the coil interval variable device 160, the resonance The input impedance of the system can be adjusted.

The communication device 170 is a communication interface for performing wireless communication with the vehicle 200. The communication device 170 can communicate various commands and data with the communication device 330 of the vehicle 200.

The ECU 190 controls power supply from the power supply facility 100 to the vehicle 200 by software processing by executing a program stored in advance by a CPU (not shown) and / or hardware processing by a dedicated electronic circuit. ECU 190 controls variable capacitor 150 based on the power reception status of vehicle 200 to adjust the resonance frequency of resonance coil 140 to the power supply frequency (the frequency of the high-frequency power output from high-frequency power supply device 110). ECU 190 controls coil interval varying device 160 based on the power reception status of vehicle 200 to adjust the impedance of the resonance system so that the input impedance of the resonance system matches the impedance of high-frequency power supply device 110.

The resonance frequency of the resonance coil is adjusted in a state where the output of the high-frequency power supply device 110 is constant (this output is higher than the output at the time of full-scale power supply for charging the power storage device 290 of the vehicle 200). This is performed based on the power reception status (for example, power reception voltage) of the vehicle 200 when the capacity of the variable capacitor 150 is swept. The resonance impedance is adjusted after the resonance frequency of the resonance coil is adjusted. When the output of the high frequency power supply device 110 is kept constant, the coil interval of the vehicle 200 is swept by the coil interval variable device 160. This is performed based on the power reception status.

Here, the ECU 190 adjusts the resonance frequency of the resonance coil 140 in a state where there is one peak of the frequency spectrum of the power reception state that changes depending on the coil interval. That is, when the coil interval changes, the power reception situation, for example, the frequency spectrum of the power reception voltage changes. Here, regarding the number of peaks in the frequency spectrum, when the coil interval is small, the frequency spectrum has one peak. However, when the coil interval increases, the frequency spectrum peak is divided into two, and the resonance frequency is adjusted by sweeping. Becomes difficult. Therefore, in this embodiment, as an example, the ECU 190 adjusts the resonance frequency of the resonance coil 140 with the coil interval narrowed so that the frequency spectrum has a single peak.

On the other hand, the vehicle 200 as a power receiving device includes a resonance coil 210, a variable capacitor 220, an electromagnetic induction coil 230, a coil interval varying device 240, a coaxial cable 250, and a rectifier 260. Vehicle 200 further includes a switching device 270, a converter 280, a power storage device 290, and a power output device 300. Furthermore, vehicle 200 further includes a resistance load 310, a detection unit 320, a communication device 330, and an ECU 350.

The resonance coil 210 receives power from the resonance coil 140 in a non-contact manner by resonating with the resonance coil 140 of the power supply facility 100 via an electromagnetic field. Note that the coil diameter and the number of turns of the resonance coil 210 are appropriately set based on the distance from the resonance coil 140 of the power supply facility 100, the resonance frequency, and the like so that the Q value is large and the degree of coupling κ is small.

The variable capacitor 220 is provided to change the resonance frequency of the resonance coil 210 and is connected between both ends of the resonance coil 210, for example. Variable capacitor 220 changes its capacity in accordance with a command received from ECU 350, and can change the resonance frequency of resonance coil 210 according to the change in capacity.

The electromagnetic induction coil 230 can be magnetically coupled to the resonance coil 210 by electromagnetic induction coupling, takes out the electric power received by the resonance coil 210 by electromagnetic induction, and outputs it to the rectifier 260 via the coaxial cable 250. For example, the electromagnetic induction coil 230 is disposed so that the central axis thereof coincides with the resonance coil 210.

The coil interval variable device 240 is a device for changing the coil interval between the resonance coil 210 and the electromagnetic induction coil 230. The coil interval varying device 240 is configured by the same mechanism as the coil interval varying device 160 of the power supply facility 100, and can change the position of the electromagnetic induction coil 230 with respect to the resonance coil 210 along the central axis of the coil. Then, by changing the coil interval using the coil interval varying device 240, the input impedance of the resonance system can be adjusted in cooperation with the coil interval varying device 160 of the power supply facility 100.

The rectifier 260 rectifies the electric power (AC) extracted from the resonance coil 210 using the electromagnetic induction coil 230. Switching device 270 switches the output destination of rectifier 260 in accordance with a command received from ECU 350. Specifically, at the time of adjusting the resonance frequency and impedance performed before full-scale power supply for charging power storage device 290, switching device 270 electrically connects resistive load 310 with rectifier 260 in accordance with a command received from ECU 350. Connect and disconnect transducer 280 electrically. When adjustment of the resonance frequency and impedance is completed, switching device 270 electrically connects converter 280 to rectifier 260 and electrically disconnects resistive load 310 in accordance with a command received from ECU 350.

Converter 280 converts the power rectified by rectifier 260 into a charging voltage in accordance with a command received from ECU 350 and outputs it to power storage device 290. Note that the converter 280 is not always necessary, and the converter 280 may be omitted depending on the output voltage of the rectifier 260 and the voltage of the power storage device 290.

The power storage device 290 is a rechargeable DC power supply, and is configured by a secondary battery such as lithium ion or nickel metal hydride. Power storage device 290 stores power supplied from power supply facility 100 and also stores power generated by power output device 300. Then, power storage device 290 supplies the stored power to power output device 300. It is to be noted that a large-capacity capacitor can also be adopted as power storage device 290, and a power buffer capable of temporarily storing power supplied from power supply facility 100 or power output device 300 and supplying the stored power to power output device 300 Anything can be used.

The power output device 300 generates the driving force for driving the vehicle 200 using the electric power stored in the power storage device 290. Although not particularly illustrated, power output device 300 includes, for example, an inverter that receives electric power output from power storage device 290, a motor driven by the inverter, a drive wheel that receives a driving force from the motor, and the like. Power output device 300 may include an engine capable of driving a generator for charging power storage device 290.

The resistive load 310 is an electrical load having a certain resistance value, and is electrically connected to the rectifier 260 by the switching device 270 when adjusting the resonance frequency and impedance as described above. Since the impedance of the power storage device 290 changes depending on the state of charge, adjustment in a state where the power storage device 290 is connected to the resonance system, in particular, impedance adjustment of the resonance system is difficult. Therefore, in this embodiment, the resonance frequency and impedance are adjusted in a state where the resistance load 310 having a constant resistance value is connected to the resonance system.

The detection unit 320 detects the voltage V and the current I indicating the power reception state when the resistive load 310 is electrically connected to the rectifier 260 when adjusting the resonance frequency and impedance, and outputs the detected values to the ECU 350. The communication device 330 is a communication interface for performing wireless communication with the communication device 170 of the power supply facility 100.

The ECU 350 controls power reception from the power supply facility 100 by software processing by executing a program stored in advance by a CPU (not shown) and / or hardware processing by a dedicated electronic circuit. ECU 350 controls switching device 270 to connect resistive load 310 to rectifier 260 when adjusting the resonance frequency and impedance. Then, ECU 350 controls variable capacitor 220 based on the power reception status detected by detection unit 320, thereby adjusting the resonance frequency of resonance coil 210 to the power supply frequency. The ECU 350 controls the coil interval variable device 240 based on the power reception status detected by the detection unit 320, thereby adjusting the resonance impedance so that the resonance input impedance matches the impedance of the high frequency power supply device 110. adjust.

Here, similarly to ECU 190 of power supply facility 100, ECU 350 also has a resonance frequency of resonance coil 210 in a state where the peak of the frequency spectrum of the power reception state that changes depending on the coil interval between resonance coil 210 and electromagnetic induction coil 230 becomes one. Adjust the frequency. In this embodiment, as an example, the ECU 350 adjusts the resonance frequency of the resonance coil 210 with the coil interval being made the narrowest so that the frequency spectrum has a single peak. Then, when the adjustment of the resonance frequency and impedance is completed, ECU 350 controls switching device 270 so that converter 280 is connected to rectifier 260.

FIG. 2 is an equivalent circuit diagram of a portion related to power transmission by the resonance method. Referring to FIG. 2, in this resonance method, two

resonance coils

140 and 210 resonate in an electromagnetic field (near field) in the same manner as two tuning forks resonate. Electric power is transmitted through an electromagnetic field.

Specifically, for example, high frequency power having a constant frequency of about several MHz to several tens of MHz is supplied from the high frequency power supply device 110 to the electromagnetic induction coil 130 and is magnetically coupled to the electromagnetic induction coil 130 by electromagnetic induction coupling. Electric power is supplied to the resonance coil 140. The resonance coil 140 can be electrically resonated by the inductance of the coil itself and the variable capacitor 150, and resonates with the resonance coil 210 on the vehicle 200 side (secondary side) via an electromagnetic field (near field). Then, energy (electric power) moves from the resonance coil 140 to the resonance coil 210 via the electromagnetic field. In order for resonance coils 140 and 210 to resonate, resonance coils 140 and 210 are designed so that the Q value is large (for example, Q> 100) and the degree of coupling κ is small.

The energy (power) transferred to the resonance coil 210 is taken out by the electromagnetic induction coil 230 that is magnetically coupled to the resonance coil 210 by electromagnetic induction coupling, and the electric system after the load 350 (rectifier 260 (FIG. 1)) is extracted. Supplied in general)

FIG. 3 is a diagram illustrating a change in frequency characteristics of a power reception situation in the vehicle 200 when the

variable capacitors

150 and 220 are changed. With reference to FIG. 3, the vertical axis indicates the magnitude of the power reception voltage indicating an example of the power reception status, and the horizontal axis indicates the frequency. The frequency f0 is a frequency of high-frequency power output from the high-frequency power supply device 110, that is, a frequency (resonance frequency) of transmitted power from the power supply facility 100 to the vehicle 200.

Curve k11 shows the frequency characteristics when the resonance frequency of the resonance coils 140 and 210 matches the frequency f0. A curve k12 shows frequency characteristics when the capacitance of the

variable capacitors

150 and 220 is smaller than that of the curve k11. The resonance frequency of the resonance coils 140 and 210 (frequency corresponding to the peak of the received voltage) is higher than the frequency f0. high. A curve k13 shows frequency characteristics when the capacitance of the

variable capacitors

150 and 220 is larger than that of the curve k11, and the resonance frequency of the resonance coils 140 and 210 is lower than the frequency f0.

As described above, when the resonance frequency of the resonance coils 140 and 210 is deviated from the frequency f0, the power reception voltage is lowered and the power reception efficiency is lowered when the power of the frequency f0 is transmitted. Therefore, in this embodiment, the

variable capacitors

150 and 220 are provided in the resonance coils 140 and 210, respectively, and the capacitances of the

variable capacitors

150 and 220 are adjusted so that the resonance frequency of the resonance coils 140 and 210 matches the frequency f0. The Specifically,

variable capacitors

150 and 220 are adjusted so that the received voltage in vehicle 200 is maximized in a state where constant power of frequency f0 is supplied.

FIG. 4 is a diagram showing a change in frequency characteristics of the power reception situation in the vehicle 200 when the coil interval between the resonance coil and the electromagnetic induction coil is changed. Referring to FIG. 4, the vertical and horizontal axes and the frequency f0 are the same as those in FIG.

As described above, when the coil interval between the electromagnetic induction coil 130 and the resonance coil 140 and the coil interval between the resonance coil 210 and the electromagnetic induction coil 230 are changed, the impedance of the resonance system changes. Then, the frequency characteristics of the received voltage change.

Curve k21 shows the frequency characteristics when the impedance of the resonance system matches the impedance of the high-frequency power supply device 110. A curve k22 shows frequency characteristics when the impedance is not matched because the coil interval between the electromagnetic induction coil 130 (210) and the resonance coil 140 (230) is smaller than that in the case of the curve k21. A curve k23 shows the frequency characteristic when the impedance is not matched because the coil interval is larger than that in the case of the curve k21.

As described above, if the impedance of the resonance system does not match the impedance of the high-frequency power supply device 110, the power receiving voltage is lowered and the power receiving efficiency is lowered when the power of the frequency f0 is transmitted. Therefore, in this embodiment, the coil spacing

variable devices

160 and 240 are provided in the power supply equipment 100 and the vehicle 200, respectively, and the resonance impedance is adjusted so that the resonance impedance matches the impedance of the high frequency power supply device 110. The Specifically, the coil

interval varying devices

160 and 240 are adjusted so that the received voltage in the vehicle 200 is maximized in a state where constant power having the frequency f0 is supplied.

Here, as shown by the curve k23, when the coil interval is large, the peak of the frequency spectrum is divided into two. Under such a frequency spectrum, it becomes difficult to adjust the resonance frequency by sweeping the capacitance of the variable capacitor. Therefore, in this embodiment, during adjustment of the resonance frequency of the resonance coil 140 (230), the electromagnetic induction coil 130 (210) and the resonance coil 140 (230) are ensured so that the frequency spectrum has a single peak. The coil interval is made the narrowest state.

Note that the size of the resistive load 310 (FIG. 1) used when adjusting the resonance frequency and impedance is determined as follows.

FIG. 5 is a diagram showing the relationship between the charging current and the charging voltage for the power storage device 290. Referring to FIG. 5, line PU indicates a constant output line with maximum charging power, and line PL indicates a constant output line with minimum charging power. Line SL indicates a constant SOC line whose SOC of power storage device 290 is the lower limit, and line SU indicates a constant SOC line whose SOC of power storage device 290 is the upper limit. A region A surrounded by the lines PU and PL and the lines SL and SU is a range that the charging voltage and charging current can take.

On the other hand, the line Im1 is a constant impedance line that intersects the line PU, which is the constant output line of the maximum charging power, in the approximate center of the lines SL and SU. The line Im2 is a constant impedance line having a larger impedance than the line Im1. Since charging of power storage device 290 is assumed to be performed with the maximum charging power, the impedance value of line Im1 is a value that is highly likely to be obtained during charging. Therefore, in this embodiment, the size of the resistance load 310 (FIG. 1) is set to the impedance value (resistance value) of the line Im1. Thereby, the resonance frequency and the impedance of the resonance system can be adjusted in a state close to the time of actual charging of power storage device 290.

FIGS. 6 and 7 are flowcharts for explaining the procedure of adjustment processing of the

variable capacitors

150 and 220 and the coil interval

variable devices

160 and 240. FIG. With reference to FIG. 1 together with FIG. 6, first, processing on the power supply equipment 100 side will be described.

The ECU 190 of the power supply facility 100 determines whether or not there is a charge request from the power supply facility 100 to the vehicle 200 (step S10). It is assumed that this charging request is generated, for example, when an appropriate input is made by the user in power supply facility 100 or vehicle 200. If there is no charge request (NO in step S10), ECU 190 proceeds to step S140 in FIG. 7 without executing a series of subsequent processes.

If it is determined in step S10 that a charging request has been made (YES in step S10), ECU 190 minimizes the coil interval between resonance coil 140 and electromagnetic induction coil 130 within a range that can be changed by coil interval varying device 160. (Step S20). At this time, communication is performed between the communication device 170 of the power supply facility 100 and the communication device 330 of the vehicle 200. Also in the vehicle 200, the resonance coil 210 and the electromagnetic induction are within a range that can be changed by the coil interval varying device 240. The coil spacing with the coil 230 is minimized.

Next, the ECU 190 controls the high frequency power supply device 110 so as to output adjustment power (step S30). The adjustment power is output to adjust the resonance frequency of resonance coils 140 and 210 and the impedance of the resonance system based on the power reception status of vehicle 200 and charges power storage device 290 of vehicle 200. Therefore, the power and frequency during full-scale power supply are the same (frequency f0), but the effective value is small.

When the output of the adjustment power is started, the ECU 190 starts sweeping the variable capacitor 150 (step S40). At this time, communication is performed between the

communication devices

170 and 330, and the variable capacitor 220 is also swept in the vehicle 200. As an example, the resonance coils 140 and 210 are the same, and the

variable capacitors

150 and 220 are also the same, and the capacitances of the

variable capacitors

150 and 220 are swept so as to be the same.

Adjustment of the

variable capacitors

150 and 220 is performed based on the power reception status of the vehicle 200 (here, the power reception voltage as an example). If an adjustment point at which the power reception voltage is maximum within the adjustable range of variable capacitor 150 is not found (NO in step S50), a stop sequence is executed (step S60). In this stop sequence, when an adjustment point at which the power reception voltage is maximized is not found, there is a possibility that the power feeding facility 100 is misaligned with the vehicle 200, more specifically, there is a possibility of misalignment between the resonance coils 140 and 210. This is processing for stopping power transmission from the power supply facility 100. This stop sequence will be described later.

When the adjustment point at which the power reception voltage becomes maximum within the adjustable range of the variable capacitor 150 is found (YES in step S50), the ECU 190 stops sweeping the variable capacitor 150 (step S70). Thereby, the adjustment of the resonance frequency of the resonance coil 140 by the variable capacitor 150 is completed.

On the other hand, in the vehicle 200, the ECU 350 determines whether or not there is a charge request from the power supply facility 100 to the vehicle 200 (step S210). If there is no charge request (NO in step S210), ECU 350 proceeds to step S360 in FIG. 7 without executing a series of subsequent processes.

If it is determined in step S210 that a charging request has been made (YES in step S210), ECU 350 controls switching device 270 to electrically disconnect converter 280 from rectifier 260, and to connect resistive load 310 to the rectifier. 260 is connected (step S220). Next, ECU 350 minimizes the coil interval between resonance coil 210 and electromagnetic induction coil 230 within a range that can be changed by coil interval variable device 240 (step S230). As described above, at this time, also in the power supply facility 100, the coil interval between the resonance coil 140 and the electromagnetic induction coil 130 is minimized.

Next, the ECU 350 starts sweeping the variable capacitor 220 (step S240). As described above, the variable capacitor 150 is also swept at the power supply facility 100 at this time.

During the sweep of the variable capacitor 220 (150), the ECU 350 determines whether or not the voltage V (power reception voltage) detected by the detection unit 320 is the maximum (step S250). As an example, when ECU 350 detects the maximum point of voltage V that changes with the sweep of variable capacitor 220 (150), ECU 350 determines that voltage V is maximum.

If no adjustment point at which the received voltage is maximum within the adjustable range of the variable capacitor 220 is found (NO in step S260), a stop sequence is executed (step S270).

If an adjustment point at which the power reception voltage is maximum within the adjustable range of variable capacitor 220 is found (YES in step S250), ECU 350 stops sweeping variable capacitor 220 (step S280). Thereby, the adjustment of the resonance frequency of the resonance coil 210 by the variable capacitor 220 is completed. When an adjustment point that maximizes the power reception voltage is found, the communication device 330 notifies the power supply facility 100 of the adjustment point, and the power supply facility 100 also stops the sweep of the variable capacitor 150 in step S70.

Referring to FIG. 7, when adjustment of the resonance frequency of resonance coil 140 is completed in power supply facility 100, ECU 190 controls coil interval variable device 160 to control the coil interval between resonance coil 140 and electromagnetic induction coil 130. Starts sweeping (step S80). During the adjustment of the resonance frequency of the resonance coil 140, the coil interval is minimized, and the coil interval sweep is performed in the direction in which the coil interval increases. At this time, communication is performed between the

communication devices

170 and 330, and also in the vehicle 200, the coil interval between the resonance coil 210 and the electromagnetic induction coil 230 is swept. As an example, the

electromagnetic induction coils

130 and 230 are the same, and are swept so that the coil interval in the power supply facility 100 and the coil interval in the vehicle 200 are the same.

The adjustment of the coil interval is also performed based on the power reception status of the vehicle 200 (here, the power reception voltage as an example). If no adjustment point at which the received voltage is maximum within the adjustable range of the coil interval is found (NO in step S90), a stop sequence is executed (step S100).

If an adjustment point at which the received voltage is maximum within the adjustable range of the coil interval is found (YES in step S90), ECU 190 stops sweeping the coil interval (step S110). Thereby, the adjustment of the impedance of the resonance system by changing the coil interval is completed.

When the adjustment of the coil interval, that is, the adjustment of the impedance of the resonance system is completed, the ECU 190 controls the high-frequency power supply device 110 to stop the output of the adjustment power (step S120). In vehicle 200, when resistive load 310 is electrically disconnected from rectifier 260 and converter 280 is connected to rectifier 260, ECU 190 performs full-scale power supply for charging power storage device 290 of vehicle 200. The high frequency power supply device 110 is controlled so as to start (step S130).

On the other hand, in the vehicle 200, when the adjustment of the resonance frequency of the resonance coil 210 is completed, the ECU 350 starts sweeping the coil interval between the resonance coil 210 and the electromagnetic induction coil 230 by controlling the coil interval variable device 240. (Step S290). During the adjustment of the resonance frequency of the resonance coil 210, the coil interval is minimized, and the coil interval sweep is performed in the direction in which the coil interval increases. As described above, at this time, also in the power supply facility 100, the coil interval between the resonance coil 140 and the electromagnetic induction coil 130 is swept.

During the execution of the coil interval sweep, the ECU 350 determines whether or not the voltage V (power reception voltage) detected by the detection unit 320 is the maximum (step S300). As an example, when ECU 350 detects the maximum point of voltage V that changes with the sweep of the coil interval, ECU 350 determines that voltage V is maximum.

If no adjustment point at which the received voltage is maximum within the adjustable range of the variable capacitor 220 is found (NO in step S310), a stop sequence is executed (step S320).

When an adjustment point at which the received voltage is maximum within the adjustable range of the coil interval is found (YES in step S300), ECU 350 stops sweeping the coil interval (step S330). Thereby, the adjustment of the coil interval, that is, the adjustment of the impedance of the resonance system is completed. When an adjustment point that maximizes the power reception voltage is found, the communication device 330 notifies the power supply facility 100 of the adjustment point, and the power supply facility 100 also stops the sweep of the coil interval in step S110.

When the adjustment of the coil interval, that is, the adjustment of the impedance of the resonance system is completed, the ECU 350 controls the switching device 270 to electrically disconnect the resistance load 310 from the rectifier 260 and connect the converter 280 to the rectifier 260 (step). S340). Then, with the start of full-scale power supply from the power supply facility 100, power reception is started in the vehicle 200 (step S350).

FIG. 8 is a flowchart for explaining the processing procedure of the stop sequence shown in FIGS. Referring to FIG. 8, in power supply facility 100, ECU 190 outputs a stop command to high frequency power supply device 110 to stop power transmission to vehicle 200 (step S410). Next, the ECU 190 outputs a warning about power transmission being stopped by the stop sequence (step S420).

On the other hand, in the vehicle 200, the ECU 350 monitors the voltage V (power reception voltage) detected by the detection unit 320, and determines whether or not the power reception voltage is lower than a threshold value (step S510). This threshold value is a threshold value for determining whether or not power transmission from the power supply facility 100 is stopped, and is set to a sufficiently small value.

When it is determined that the received voltage has become lower than the threshold (YES in step S510), ECU 350 controls switching device 270 to electrically disconnect converter 280 from rectifier 260 (step S520). Then, ECU 350 outputs an alarm that power transmission has been stopped by the stop sequence (step S530).

As described above, in this embodiment, the resonance frequency of the resonance coils 140 and 210 is first adjusted, and after adjustment of the resonance frequency, the coil interval between the resonance coil 140 (210) and the electromagnetic induction coil (130, 210). Is adjusted. Here, the adjustment of the resonance frequency is performed in a state where the coil interval is the narrowest in the adjustable range of the coil interval. As a result, as shown in FIGS. 3 and 4, the resonance frequency is adjusted with one peak of the frequency spectrum. Therefore, according to the present invention, the resonance frequency of the resonance coils 140 and 210 can be easily adjusted.

In this embodiment, the resonance frequency of the resonance coils 140 and 210 is first adjusted, and after the resonance frequency is adjusted, the impedance is adjusted by changing the coil interval. Therefore, according to this embodiment, adjustment for realizing the maximum efficiency can be easily performed.

Further, in this embodiment, when adjustment is not possible within the adjustable range of the

variable capacitors

150 and 220 and the coil interval

variable devices

160 and 240, there is a possibility of displacement between the resonance coils 140 and 210. When it stops, an alarm is output. Therefore, according to this embodiment, in the case of a positional deviation between the resonance coils 140 and 210, the user can be notified of the possibility of the positional deviation after power transmission is stopped.

In the above embodiment, the resonance frequency and coil interval of the resonance coil are adjusted based on the received voltage, but based on the reflected power detected by the power sensor 115 provided in the power supply facility 100, The resonance frequency and the coil interval may be adjusted.

FIG. 9 is a diagram showing changes in the frequency characteristics of the reflected power when the

variable capacitors

150 and 220 are changed. Referring to FIG. 9, the vertical axis indicates the magnitude of the reflected power detected by power sensor 115 (FIG. 1), and the horizontal axis indicates the frequency. The frequency f0 is a frequency of high-frequency power output from the high-frequency power supply device 110, that is, a frequency (resonance frequency) of transmitted power from the power supply facility 100 to the vehicle 200.

Curve k31 shows the frequency characteristics when the resonance frequency of the resonance coils 140 and 210 matches the frequency f0. A curve k32 shows frequency characteristics when the capacitance of the

variable capacitors

150 and 220 is smaller than that of the curve k31. The resonance frequency of the resonance coils 140 and 210 (frequency corresponding to the minimum value of the reflected power) is higher than the frequency f0. Is also expensive. A curve k33 shows frequency characteristics when the capacitance of the

variable capacitors

150 and 220 is larger than that of the curve k31, and the resonance frequency of the resonance coils 140 and 210 is lower than the frequency f0.

When the resonance frequency of the resonance coils 140 and 210 deviates from the frequency f0, the reflected power increases at the frequency f0 of the transmission power, and the power reception efficiency decreases. Therefore, the resonance frequency of the resonance coils 140 and 210 is adjusted by adjusting the

variable capacitors

150 and 220 so that the reflected power is minimized while the constant power of the frequency f0 is output from the high frequency power supply device 110. Can do.

Although not particularly illustrated, the coil interval between the resonance coil 140 (210) and the electromagnetic induction coil 130 (230) may also be adjusted based on the reflected power detected by the power sensor 115. Good.

In the above embodiment, as an example, the resonance frequency of the resonance coils 140 and 210 is adjusted by making the coil interval the narrowest so that the peak of the frequency spectrum of the power reception state is surely one. However, when the resonance frequency is adjusted, it is only necessary to have one peak of the frequency spectrum, and it is not essential to make the coil interval the narrowest. If the coil interval is somewhat narrow, even if the coil interval is not the narrowest state, the peak of the frequency spectrum can be one.

In the above embodiment, the ECU 190 of the power supply facility 100 and the ECU 350 of the vehicle 200 share functions as shown in FIGS. 6 to 8, but all of the functions of one of the

ECUs

190 and 350 or A part may be provided to the other ECU.

In the above description, the resonance coil 140 corresponds to one embodiment of the “power transmission coil” in the present invention, and the resonance coil 210 corresponds to one embodiment of the “power reception coil” in the present invention. The electromagnetic induction coil 230 corresponds to one embodiment of the “electromagnetic induction coil for taking out the electric power received by the power receiving coil by electromagnetic induction” in the present invention. This corresponds to an example of the “first changing device for changing the resonance frequency of the power receiving coil”. Further, the coil interval varying device 240 corresponds to an embodiment of “a second changing device for changing the coil interval between the power receiving coil and the electromagnetic induction coil” in the present invention. This corresponds to an example of the “control device” in the invention of the present invention.

Furthermore, the high frequency power supply device 110 corresponds to an embodiment of the “power supply device” in the present invention, and the electromagnetic induction coil 130 corresponds to “the power transmission coil by receiving electric power from the power supply device and performing electromagnetic induction” This corresponds to an embodiment of "electromagnetic induction coil for supplying to". Furthermore, the variable capacitor 150 corresponds to an embodiment of “a first changing device for changing the resonance frequency of the power transmission coil” according to the present invention. This corresponds to an example of the “second changing device for changing the coil interval between the power transmission coil and the electromagnetic induction coil”. Further, ECU 190 corresponds to an embodiment of “control device” in the invention of the power supply facility.

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, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

100 power supply equipment, 110 high frequency power supply device, 115 power sensor, 120, 250 coaxial cable, 130, 230 electromagnetic induction coil, 140, 210 resonance coil, 150, 220 variable capacitor, 160, 240 coil interval variable device, 170, 330 communication Device, 190, 350 ECU, 200 vehicle, 260 rectifier, 270 switching device, 280 converter, 290 power storage device, 300 power output device, 310 resistance load, 320 detection unit, 350 load.

Claims

A power receiving device for receiving power from a power supply facility (100) including a power transmission coil (140) in a non-contact manner,
A power receiving coil (210) for receiving power from the power transmitting coil in a non-contact manner by resonating with the power transmitting coil via an electromagnetic field;
An electromagnetic induction coil (230) for extracting the electric power received by the power receiving coil by electromagnetic induction;
A first changing device (220) for changing a resonance frequency of the power receiving coil;
A second changing device (240) for changing a coil interval between the power receiving coil and the electromagnetic induction coil;
A control device that first adjusts the resonance frequency to a predetermined frequency by controlling the first changing device, and adjusts the coil interval by controlling the second changing device after adjusting the resonance frequency ( 350),
The control device is a power reception device that adjusts the resonance frequency in a state where there is one peak of a frequency spectrum of a power reception state that changes depending on the coil interval.
2. The power receiving device according to claim 1, wherein the control device adjusts the resonance frequency in a state where the coil interval is the narrowest in an adjustable range of the coil interval.
The power receiving device according to claim 1 or 2, wherein the control device adjusts the coil interval by changing the coil interval in a direction in which the coil interval increases.
2. The power receiving device according to claim 1, wherein the control device stops output to an electric load connected to the power receiving device when the resonance frequency cannot be adjusted to the predetermined frequency within an adjustable range of the resonance frequency. .
The power receiving device according to claim 1, wherein the control device stops output to an electric load connected to the power receiving device when the adjustment of the coil interval is not completed within the adjustable range of the coil interval.
The power receiving device according to claim 4 or 5, wherein the control device outputs an alarm when the output to the electric load is stopped.
The power receiving device according to claim 1 or 2, wherein the first changing device includes a variable capacitor (220) connected to the power receiving coil.
A vehicle comprising the power receiving device according to claim 1 or 2.
A power supply facility for supplying power in a non-contact manner to a power receiving device (200) including a power receiving coil (210),
A power transmission coil (140) for non-contact power transmission to the power reception coil by resonating with the power reception coil via an electromagnetic field;
A power supply device (110) for generating power having a predetermined frequency;
An electromagnetic induction coil (130) for receiving electric power from the power supply device and supplying the electric power to the power transmission coil by electromagnetic induction;
A first changing device (150) for changing a resonance frequency of the power transmission coil;
A second changing device (160) for changing a coil interval between the power transmission coil and the electromagnetic induction coil;
A control device that first adjusts the resonance frequency to a predetermined frequency by controlling the first changing device, and adjusts the coil interval by controlling the second changing device after adjusting the resonance frequency ( 190)
The said control apparatus is electric power feeding equipment which adjusts the said resonant frequency in the state in which the peak of the frequency spectrum of the power receiving condition of the said power receiving apparatus which changes with the said coil space | interval becomes one.
The power supply equipment according to claim 9, wherein the control device adjusts the resonance frequency in a state in which the coil interval is narrowed within the adjustable range of the coil interval.
The power supply equipment according to claim 9 or 10, wherein the control device adjusts the coil interval by changing the coil interval in a direction in which the coil interval increases.
The power supply equipment according to claim 9, wherein the control device stops the power supply device when the resonance frequency cannot be adjusted to the predetermined frequency within an adjustable range of the resonance frequency.
The power supply equipment according to claim 9, wherein the control device stops the power supply device when the adjustment of the coil interval is not completed within the adjustable range of the coil interval.
The power supply facility according to claim 12 or 13, wherein the control device outputs an alarm when the power supply device is stopped.
The power supply equipment according to claim 9 or 10, wherein the first changing device includes a variable capacitor (150) connected to the power transmission coil.
A power supply device (110) for generating power having a predetermined frequency;
A first electromagnetic induction coil (130) for receiving power from the power supply and supplying power by electromagnetic induction;
A power transmission coil (140) that receives power from the first electromagnetic induction coil;
A power receiving coil (210) for receiving power from the power transmitting coil in a non-contact manner by resonating with the power transmitting coil via an electromagnetic field;
A second electromagnetic induction coil (230) for taking out the electric power received by the power reception coil by electromagnetic induction;
A first frequency changing device (150) for changing a first resonant frequency indicating a resonant frequency of the power transmission coil;
A second frequency changing device (220) for changing a second resonance frequency indicating the resonance frequency of the power receiving coil;
A first interval changing device (160) for changing a first coil interval indicating a coil interval between the power transmission coil and the first electromagnetic induction coil;
A second interval changing device (240) for changing a second coil interval indicating a coil interval between the power receiving coil and the second electromagnetic induction coil;
The first and second resonance frequencies are first adjusted to a predetermined frequency by controlling the first and second frequency changing devices, and after the adjustment of the first and second resonance frequencies, the first and second resonance frequencies are adjusted. A control device (190, 350) for adjusting the first and second coil intervals by controlling a second interval changing device;
The power supply system, wherein the control device adjusts the first and second resonance frequencies in a state where a peak of a frequency spectrum of a power reception state that changes depending on a distance between the first and second coils becomes one.
The control device is configured such that the first and second coil intervals are the narrowest in the adjustable range of the first coil interval and the adjustable range of the second coil interval, respectively. The power feeding system according to claim 16, wherein the resonance frequency is adjusted.