JP2014017752A - Coupling circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extract a communication signal from supply power independently of the supply power and superimpose a communication signal independently of the supply power, in a contactless feeding system for supplying power from a feeding apparatus to a charging apparatus mounted on a vehicle in a contactless manner.SOLUTION: A coupling circuit 10 includes: a filter circuit 31 in which a coil 34 and a capacitor 35 connected in parallel with a communication section 9 and with a contactless feeding coil 12 have an inductance and a capacitance set such that a resonance frequency set by the coil 34 and the capacitor 35 matches the frequency of supply power; and filter circuits 32, 33 in each of which a coil 36 and a capacitor 37 connected in series with the communication section 9 and with the contactless feeding coil 12 have an inductance and a capacitance set such that a resonance frequency set by the coil 36 and the capacitor 37 matches the frequency of a communication signal.

Description

  The present invention relates to a coupling circuit for superimposing a communication signal on electric power supplied in a non-contact manner to a vehicle or taking out a communication signal from the supplied electric power.

In order to charge a battery mounted on a vehicle such as a hybrid vehicle or an electric vehicle, there is a non-contact power feeding system that supplies power from a power feeding device to a charging device mounted on the vehicle in a contactless manner.
In such a non-contact power feeding system, information exchange between the power feeding device and the charging device is also performed in a non-contact manner. For example, there is one that exchanges information between a power supply apparatus and a charging apparatus by superimposing a communication signal on power supplied from the power supply apparatus to the charging apparatus. In this case, it is necessary to provide the power feeding device and the charging device with a coupling circuit for superimposing the communication signal on the supplied power or extracting the communication signal from the supplied power. The coupling circuit includes, for example, a bandpass filter circuit or a notch filter circuit that can pass a signal corresponding to the frequency of the communication signal while blocking a signal corresponding to the frequency of the supplied power (for example, a patent) References 1 and 2).

JP 2005-236815 A JP 2003-134003 A

Incidentally, the power (for example, several kW) supplied from the power supply apparatus to the charging apparatus is usually larger than the power (for example, several W) of the communication signal.
In addition, in order to exchange the communication signal on the supply power and exchange it between the power supply apparatus and the charging apparatus, the frequency of the communication signal needs to be as close as possible to the frequency of the supply power.

  Therefore, for example, in the case where the coupling circuit is configured by a band-pass filter circuit that passes a signal with respect to the frequency of the communication signal, there is a possibility that the supplied power cannot be sufficiently attenuated. May be included.

  For example, when the coupling circuit is configured by a notch filter circuit that does not pass a signal for the frequency of the supplied power, the supplied power can be sufficiently attenuated when viewed from the transmission / reception side of the communication signal. When viewed from the side, the supplied power may be attenuated below a required level.

  In view of this, the present invention provides a contactless power supply system that supplies power in a contactless manner from a power supply device to a charging device mounted on a vehicle, and extracts a communication signal from the supplied power so as not to be affected by the supplied power. The purpose is to superimpose communication signals without affecting them.

  The coupling circuit according to the present invention includes a first contactless power supply coil of a power supply device and a second contactless power supply coil of a charging device mounted on a vehicle. In the non-contact power supply system that supplies power, the communication signal output from the communication unit is superimposed on the power supplied from the power supply device to the charging device in a non-contact manner, or the communication signal is extracted from the supplied power.

The coupling circuit of the present invention includes a first filter circuit and a second filter circuit.
The first filter circuit includes a first coil and a first capacitor that are connected in series to each other and connected in parallel to the communication unit and the first or second contactless power supply coil, respectively. The inductance of the first coil and the capacitance of the first capacitor are set so that the frequency matches the frequency of the supplied power.

  The second filter circuit includes a second coil and a second capacitor connected in series to each other and connected in series to the communication unit and the first or second contactless power supply coil. The inductance of the second coil and the capacitance of the second capacitor are set so that the resonance frequency matches the frequency of the communication signal.

  Accordingly, in the first filter circuit, the passage loss with respect to the frequency of the supplied power can be increased, and the passage loss with respect to the frequency of the communication signal can be reduced. In the second filter circuit, the passage loss with respect to the frequency of the communication signal can be reduced. Can be reduced. Thereby, since only supply power can be sufficiently attenuated when viewed from the communication unit side, a communication signal can be extracted from the supply power without being affected by the supply power. In the second filter circuit, the impedance with respect to the frequency of the supplied power can be made higher than the impedance with respect to the frequency of the communication signal. As a result, it is possible to prevent the supplied power from being attenuated by the first filter circuit or the like when viewed from the first or second contactless power supply coil side, so that the communication signal is superimposed without affecting the supplied power. be able to.

The first and second filter circuits may be connected in multiple stages.
As a result, the Q value of the entire first filter circuit and the Q value of the entire second filter circuit are increased, so that only the supplied power can be further attenuated as viewed from the communication unit side.

  Further, the coupling circuit of the present invention is provided between the first and second filter circuits, between the first or second contactless power supply coil and the second filter circuit, or between the first and second filter circuits. A transformer provided between the filter circuit and the communication unit may be provided.

  Thereby, the 1st non-contact electric power feeding coil (or 2nd non-contact electric power feeding coil) of a high voltage | pressure side and the communication part of a low voltage | pressure side can be insulated more reliably.

  According to the present invention, in a contactless power supply system that supplies power from a power supply device to a charging device mounted on a vehicle in a contactless manner, a communication signal is extracted from the supplied power so as not to be affected by the supplied power, and It is possible to superimpose communication signals without affecting them.

It is a figure which shows the non-contact electric power feeding system of embodiment of this invention. It is a figure which shows an example of a superimposition communication apparatus. It is a figure which shows an example of a coupling circuit. It is a figure which shows the other example of a coupling circuit. It is a figure which shows the further another example of a coupling circuit.

FIG. 1 is a diagram illustrating a contactless power feeding system according to an embodiment of the present invention.
The non-contact power feeding system 1 shown in FIG. 1 supplies the power obtained from the system power source 2 from the power feeding device 3 to the charging device 5 mounted on the vehicle 4 in a non-contact manner. The power supplied from the power supply device 3 to the charging device 5 in a non-contact manner is hereinafter referred to as supply power.

The power feeding device 3 includes a power feeding unit 6, a superimposed communication device 7, and a resonance circuit 8.
The power feeding unit 6 increases the frequency and voltage of power obtained from the system power supply 2 to a desired frequency and voltage.

The superimposing communication device 7 includes a communication unit 9 and a coupling circuit 10.
The communication unit 9 generates a communication signal indicating information to be transmitted to the charging device 5 and outputs the communication signal to the coupling circuit 10 or receives a communication signal output from the coupling circuit 10.

  The coupling circuit 10 superimposes the communication signal output from the communication unit 9 on the supply power transmitted to the power supply cable 11 that connects the power supply unit 6 and the resonance circuit 8 or feeds the communication signal transmitted from the charging device 5. The supply power transmitted to the cable 11 is taken out and output to the communication unit 9.

  The resonance circuit 8 includes a non-contact power supply coil 12 (first non-contact power supply coil) connected in parallel with the superimposing communication device 7. The resonance circuit 8 may further include a capacitor connected in parallel to the contactless power feeding coil 12. The supplied power output from the power feeding unit 6 is transmitted to the resonance circuit 8 via the superimposed communication device 7 and is transmitted from the resonance circuit 8 to the charging device 5 in a non-contact manner. Note that the non-contact power transmission method of the present embodiment is not limited to the magnetic field resonance method, and may be, for example, an electromagnetic induction method or a radio wave method. A matching circuit may be provided between the superimposing communication device 7 and the resonance circuit 8. This matching circuit is a circuit for matching the impedance on the superimposed communication device 7 side and the impedance on the resonance circuit 8 side, and is constituted by, for example, a coil or a capacitor.

The charging device 5 includes a resonance circuit 13, a superimposed communication device 14, and a rectifier circuit 15.
The resonance circuit 13 includes a non-contact power supply coil 16 (second non-contact power supply coil) connected in parallel with the superimposing communication device 14. The resonance circuit 13 may further include a capacitor connected in parallel to the non-contact power supply coil 16. Further, a matching circuit may be provided between the resonance circuit 13 and the superimposed communication device 14. This matching circuit is a circuit for making the impedance on the resonance circuit 13 side and the impedance on the superimposed communication device 14 side coincide with each other, and is constituted by, for example, a coil or a capacitor.

The superimposing communication device 14 includes a communication unit 17 and a coupling circuit 18.
The communication unit 17 generates a communication signal indicating information to be transmitted to the power supply device 3 and outputs the communication signal to the coupling circuit 18 or receives a communication signal output from the coupling circuit 18.

  The coupling circuit 18 superimposes the communication signal output from the communication unit 17 on the supply power transmitted to the power supply cable 19 that connects the resonance circuit 13 and the rectifier circuit 15, or supplies the communication signal transmitted from the power supply device 3. The supply power transmitted to the cable 19 is taken out and output to the communication unit 17.

  The rectifier circuit 15 rectifies the supply power transmitted from the power supply unit 6 of the power supply device 3 via the superimposed communication device 7, the resonance circuits 8 and 13, and the superimposed communication device 14, and the vehicle 4 uses the rectified supply power. The battery 20 mounted on the battery is charged.

FIG. 2 is a diagram illustrating an example of the communication unit 9 of the power feeding device 3. The communication unit 17 of the charging device 5 is the same as the communication unit 9.
The communication unit 9 illustrated in FIG. 2 includes a transmission circuit 21 and a reception circuit 22.

The transmission circuit 21 includes an encoder 23, a modulation unit 24, an amplifier 25, and a filter 26.
The encoder 23 outputs information (for example, a charge start instruction, a charge end instruction, or an upper limit value of the charge current) sent from a control circuit (not shown) such as a microcomputer as a pulse signal. For example, the encoder 23 sets the “1” portion of the code character string consisting of “1” and “0” as information sent from a control circuit (not shown) to the high level, and sets the “0” portion to the low level. Output a pulse signal.

  The modulation unit 24 generates and outputs a communication signal by digitally modulating a sine wave having a frequency different from the supplied power with the pulse signal output from the encoder 23. Note that the modulation method in the modulation unit 24 is ASK (Amplitude Shift Keying), FM (Frequency Modulation), FSK (Frequency Shift Keying), PSK (Phase Shift Keying), OFDM (Orthogonal Frequency Division Multiplexing), or SS (Spread Spectrum). ) And the like.

The amplifier 25 amplifies the communication signal output from the modulation unit 24.
The filter 26 removes a signal corresponding to noise from the communication signal output from the amplifier 25.

  The communication signal output from the filter 26 is superimposed on the supplied power by the coupling circuit 10. In addition, the coupling circuit 10 extracts a communication signal transmitted from the charging device 5 from the supplied power and transmits the communication signal to the receiving circuit 22.

The reception circuit 22 includes a filter 27, a low noise amplifier 28, a demodulation unit 29, and a decoder 30.
The filter 27 removes a signal corresponding to noise from the communication signal extracted by the coupling circuit 10.

The low noise amplifier 28 amplifies the communication signal output from the filter 27.
The demodulator 29 outputs a pulse signal by digitally demodulating the communication signal output from the low noise amplifier 28.

The decoder 30 acquires information (for example, a charge start instruction, a charge end instruction, or an upper limit value of the charge current) by decoding the pulse signal output from the demodulator 29.
FIG. 3A is a diagram illustrating an example of the coupling circuit 10 (or the coupling circuit 18).

  The coupling circuit 10 (or coupling circuit 18) shown in FIG. 3A includes a filter circuit 31 (first filter circuit), a filter circuit 32 (second filter circuit), and a filter circuit 33 (second filter circuit). Filter circuit).

  The filter circuit 31 includes a coil 34 (first coil) and a capacitor 35 (first capacitor). The coil 34 and the capacitor 35 are connected in series to each other, and are connected in parallel to the communication unit 9 and the non-contact power supply coil 12 (or the non-contact power supply coil 16). Further, the inductance of the coil 34 and the capacitance of the capacitor 35 are set so that the resonance frequency of the filter circuit 31 matches the frequency of the supplied power. Thereby, for example, as shown in FIG. 3B, the filter circuit 31 functions as a notch filter circuit capable of increasing the passage loss with respect to the frequency of the supplied power and reducing the passage loss with respect to the frequency of the communication signal. Can be made.

  Each of the filter circuits 32 and 33 includes a coil 36 (second coil) and a capacitor 37 (second capacitor). The coil 36 and the capacitor 37 are connected in series to each other, and are also connected in series to the communication unit 9 and the non-contact power supply coil 12 (or the non-contact power supply coil 16). Further, the inductance of the coil 36 and the capacitance of the capacitor 37 are set so that the resonance frequency of the filter circuits 32 and 33 matches the frequency of the communication signal. Thereby, the filter circuits 32 and 33 can be made to function as a band pass filter circuit which can make the passage loss with respect to the frequency of a communication signal small, for example as shown in FIG.3 (c). Moreover, the filter circuits 32 and 33 can make the impedance with respect to the frequency of supply power higher than the impedance with respect to the frequency of a communication signal.

  For example, when the frequency of the supplied power is 150 [kH] and the frequency of the communication signal is 170 [kH], the inductance of the coil 34 is 0.47 [mH] and the capacitance of the capacitor 35 is 2400 [pF]. It is desirable to set the inductance of the coil 36 to 1.5 [mH] and the capacitance of the capacitor 37 to 580 [pF].

  Thus, in the coupling circuit 10 of the present embodiment, the filter circuit 31 can increase the passage loss with respect to the frequency of the supplied power and can reduce the passage loss with respect to the frequency of the communication signal. Thus, it is possible to reduce the passage loss with respect to the frequency of the communication signal. Thereby, in order to superimpose the communication signal on the supply signal and transmit it from the power supply device 3 to the charging device 5 in a non-contact manner, even if the frequency of the communication signal is close to the frequency of the supply power, the supply power is the power of the communication signal. Even if the value is larger than that, only the supplied power can be sufficiently attenuated when viewed from the communication unit 9 side, and therefore a communication signal can be extracted from the supplied power so as not to be affected by the supplied power.

  Moreover, in the coupling circuit 10 of this embodiment, in the filter circuits 32 and 33, the impedance with respect to the frequency of supplied power can be made higher than the impedance with respect to the frequency of a communication signal. Accordingly, since it is possible to prevent the supplied power from being attenuated by the filter circuit 31 or the like when viewed from the contactless power supply coil 12 (or contactless power supply coil 16) side, the communication signal can be transmitted without affecting the supply power. Can be superimposed.

  In the above-described embodiment, the coupling circuit 10 is configured by the filter circuits 31 to 33. However, the coupling circuit 10 may be configured by connecting a plurality of stages of the filter circuits 31 to 33. For example, as illustrated in FIG. 4, the coupling circuit 10 may be configured by connecting two sets of filter circuits 31 to 33 in two stages. When configured in this way, the Q value of each filter circuit 31 as a whole and the Q values of each filter circuit 32 and 33 as a whole are higher than when the coupling circuit 10 is configured by one stage of filter circuits 31 to 33. Therefore, only the supplied power can be further attenuated when viewed from the communication unit 9 side.

  Further, the coupling circuit 10 of the above embodiment may further include a transformer. For example, as illustrated in FIG. 5, a transformer 50 may be provided between the filter circuit 31 and the filter circuits 32 and 33. The transformer 50 may be provided between the power supply cable 11 (or the power supply cable 19) and the filter circuits 32 and 33, or between the filter circuit 31 and the communication unit 9. When configured in this manner, the high-voltage side non-contact power supply coil 12 (or the non-contact power supply coil 16) and the low-voltage side communication unit 9 can be more reliably insulated.

DESCRIPTION OF SYMBOLS 1 Non-contact electric power feeding system 2 System power supply 3 Electric power feeder 4 Vehicle 5 Charging apparatus 6 Electric power feeding part 7 Superimposition communication machine 8 Resonance circuit 9 Communication part 10 Coupling circuit 11 Feeding cable 12 Non-contact electric power feeding coil 13 Resonance circuit 14 Superposition communication machine 15 Rectifier circuit 16 Non-contact power supply coil 17 Communication unit 18 Coupling circuit 19 Power supply cable 20 Battery 31-33 Filter circuit 34, 36 Coil 35, 37 Capacitor 50 Transformer

Claims (3)

In a non-contact power feeding system that supplies power from the power feeding device to the charging device in a non-contact manner via a first non-contact power feeding coil of the power feeding device and a second non-contact power feeding coil of a charging device mounted on a vehicle. A coupling circuit that superimposes a communication signal output from a communication unit on power supplied from the power supply device to the charging device in a contactless manner, or extracts the communication signal from the supplied power,
A first coil and a first capacitor connected in series to each other and connected in parallel to the communication unit and the first or second contactless power supply coil, respectively, the first coil and the first capacitor A first filter circuit in which an inductance of the first coil and a capacitance of the first capacitor are set such that a resonance frequency set by the capacitor of the first coil coincides with a frequency of the supplied power;
A second coil and a second capacitor connected in series to each other and connected in series to the communication unit and the first or second contactless power supply coil, respectively, the second coil and the second capacitor A second filter circuit in which an inductance of the second coil and a capacitance of the second capacitor are set such that a resonance frequency set by the capacitor of the second coil matches the frequency of the communication signal;
A coupling circuit comprising: The coupling circuit according to claim 1,
The coupling circuit, wherein the first and second filter circuits are connected in multiple stages. The coupling circuit according to claim 1 or 2, wherein
Between the first and second filter circuits, between the first or second contactless power supply coil and the second filter circuit, or between the first filter circuit and the communication unit. A coupling circuit comprising a transformer provided.

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