JP2013038760A - Communication system and communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system and a communication device, capable of reliably performing transmission and reception of a signal between an output circuit and an input circuit, even when a communication circuit other than a control pilot communication circuit is connected to a control pilot line.SOLUTION: An output circuit 20 transmits a control pilot signal generated at a voltage generation source 21 to an input circuit 60. Between a control pilot line 4 on an output side of the output circuit 20 and a ground line 3, a series circuit of a series resonant circuit 31 which does not increase a rounding of the control pilot communication signal and a communication part 30 is connected. Between a control pilot line 4 on an input side of the input circuit 60 and the ground line 3, a series circuit of a series resonant circuit 71 and a communication part 70 is connected.

Description

  The present invention relates to a communication system that performs communication between a vehicle such as an electric vehicle or a hybrid vehicle and a power supply device that supplies power to the vehicle, and a communication device that constitutes the communication system.

  In recent years, attention has been focused on environmental technology as a technology to cope with global warming. As such an environmental technology, for example, an electric vehicle equipped with a secondary battery and employing a motor as a driving device instead of a conventional gasoline consuming engine, a hybrid vehicle, etc. have been put into practical use. Yes.

  A vehicle such as an electric vehicle or a hybrid vehicle can charge a secondary battery from the outside of the vehicle by connecting a charging plug connected to an external power feeding device to a connector of a power feeding port provided in the vehicle. It can be configured.

  The interface between the vehicle and the power supply device (charging station) when supplying power to the vehicle has already been standardized. For example, a signal line called a control pilot line is provided between an output circuit provided on the power supply device side and an input circuit provided on the vehicle side, and a rectangular with a predetermined frequency is provided from the output circuit to the input circuit. By outputting a wave signal (control pilot signal), information such as a charging state of the vehicle can be confirmed between the power feeding device and the vehicle (see Non-Patent Document 1).

  On the other hand, a communication system that can transmit and receive various kinds of information between the power supply apparatus and the vehicle by superimposing a communication signal on the control pilot line is also being studied.

SAE International (Society of Automotive Engineers International), SURFACE VEHICLE RECOMMENDED PRACTICE, 2010-01 (Society of Automotive Engineers International, Surface Vehicle Recommended Practice, January 2010)

  However, when a communication circuit other than the control pilot communication circuit is connected to the control pilot line, depending on the value of the element that determines the frequency band, the distortion of the control pilot signal increases, and the control pilot between the output circuit and the input circuit There is a problem that signals cannot be transmitted and received.

  The present invention has been made in view of such circumstances. Even when a communication circuit other than the control pilot communication circuit is connected to the control pilot line, signal transmission / reception between the output circuit and the input circuit is reliably performed. It is an object of the present invention to provide a communication system that can perform communication and a communication device that constitutes the communication system.

  A communication system according to a first aspect of the present invention is provided in a power feeding device that supplies power to a vehicle, and is provided with an output circuit that outputs a rectangular wave signal having a predetermined frequency, and is provided in the vehicle, and is connected to the output circuit through a plurality of signal lines. An input circuit to which a rectangular wave signal output from the output circuit is input, and a communication signal is superimposed on the signal line to perform communication between the vehicle and the power supply device. A first communication unit that is connected between the signal lines via a first series resonance circuit and transmits / receives a communication signal; and provided in the vehicle via a second series resonance circuit between the signal lines. And a second communication unit that transmits and receives a communication signal, and the first and second series resonance circuits are configured to block higher harmonics than the ninth harmonic having the predetermined frequency as a fundamental wave. Features.

  A communication system according to a second invention is characterized in that, in the first invention, the first and second series resonance circuits block higher harmonics of the fifteenth harmonic or higher with the predetermined frequency as a fundamental wave. .

  A communication system according to a third invention is characterized in that, in the first invention or the second invention, the first and second series resonant circuits have a pass band of 1.75 MHz to 1.8 MHz.

  A communication system according to a fourth invention is the communication system according to any one of the first to third inventions, wherein the vehicle further includes a low-pass filter that is interposed in the signal line and allows the rectangular wave signal to pass therethrough. The second communication unit is located between the connection position and the input circuit.

  According to a fifth aspect of the present invention, there is provided a communication apparatus comprising: an output circuit that outputs a rectangular wave signal having a predetermined frequency via a plurality of signal lines; the signal lines are connected via a series resonance circuit; A communication unit for transmitting and receiving communication signals by superimposing communication signals on a line, wherein the series resonance circuit cuts off a higher harmonic than a ninth harmonic having the predetermined frequency as a fundamental wave; .

  According to a sixth aspect of the present invention, there is provided a communication apparatus comprising: an output circuit that outputs a rectangular wave signal having a predetermined frequency through a plurality of signal lines; the signal lines are connected via a series resonance circuit; A communication unit that transmits and receives a communication signal by superimposing a communication signal on a line, wherein the series resonance circuit cuts off a higher harmonic than the 15th harmonic having the predetermined frequency as a fundamental wave. .

  According to a seventh aspect of the present invention, there is provided a communication apparatus according to a seventh aspect of the present invention, comprising: an input circuit to which a rectangular wave signal having a predetermined frequency is input via a plurality of signal lines; and a signal connected between the signal lines via a series resonance circuit. A communication unit for transmitting and receiving communication signals by superimposing communication signals on a line, wherein the series resonance circuit cuts off a higher harmonic than a ninth harmonic having the predetermined frequency as a fundamental wave; .

  According to an eighth aspect of the present invention, there is provided a communication apparatus including: an input circuit to which a rectangular wave signal having a predetermined frequency is input via a plurality of signal lines; the signal line is connected between the signal lines via a series resonance circuit; A communication unit that transmits and receives a communication signal by superimposing a communication signal on a line, wherein the series resonance circuit cuts off a higher harmonic than the 15th harmonic having the predetermined frequency as a fundamental wave. .

  In the first invention, the fifth invention, and the seventh invention, the first communication unit is provided in the power feeding device, and includes a plurality of signal lines (for example, a control pilot line and a ground line) between the output circuit and the input circuit. ) Are connected via a first series resonant circuit, and the communication signal is transmitted and received by superimposing the communication signal on the signal line. In addition, the second communication unit is provided in the vehicle, connected to the plurality of signal lines between the output circuit and the input circuit via the second series resonance circuit, and the communication signal is superimposed on the signal line to communicate the signal. Send and receive. The series resonant circuit is, for example, a series circuit of an inductor, a capacitor, and a resistor. That is, a series circuit of the first communication unit and the first series resonance circuit is connected between the signal lines, and a series circuit of the second communication unit and the second series resonance circuit is connected between the signal lines. The first and second communication units perform communication by superimposing a communication signal of a desired frequency band on a signal line via a series resonance circuit. The desired frequency band is, for example, 1.75 MHz to 1.8 MHz (FSK: frequency shift keying).

  The first and second series resonant circuits block higher harmonics that are higher than the ninth harmonic with the frequency of a predetermined rectangular wave generated by the output circuit as a fundamental wave. The frequency of the predetermined rectangular wave is, for example, 1 kHz. Thereby, the harmonic component of the rectangular wave signal (control pilot signal) having a predetermined frequency generated by the output circuit propagates to the first communication unit and the second communication unit, thereby increasing the distortion of the rectangular wave signal. Even when a communication circuit other than the control pilot communication circuit is connected to the control pilot line, it is possible to reliably transmit and receive the control pilot signal between the output circuit and the input circuit.

  In the second invention, the sixth invention, and the eighth invention, the first and second series resonant circuits are higher than the 15th harmonic with the frequency of the predetermined rectangular wave generated by the output circuit as a fundamental wave. Shut off. As a result, the higher-order harmonic component of the rectangular wave signal (control pilot signal) having a predetermined frequency generated by the output circuit is blocked from propagating to the first communication unit and the second communication unit, thereby generating a rectangular wave. Signal distortion can be prevented from increasing, and even when a communication circuit other than the control pilot communication circuit is connected to the control pilot line, signal transmission and reception between the output circuit and the input circuit can be performed more reliably. Can do.

  In the third invention, the first and second series resonant circuits have a passband of 1.75 MHz to 1.8 MHz. In order to set the resonance frequency of the series resonance circuit, the values of the capacitor and the inductor can be arbitrarily set according to the pass band. However, when a communication circuit is connected to the control pilot line, distortion of the control pilot signal occurs when the capacitor and the inductor are set to arbitrary values. Therefore, by fixing the value of the capacitor of the series resonance circuit to a predetermined value (for example, 1 nF) or less, and setting the value of the inductor of the series resonance circuit so as to obtain a required resonance frequency (passband), By shifting the resonance frequency, a required pass band of 1.75 MHz to 1.8 MHz can be realized.

  In the fourth invention, the low-pass filter that allows the rectangular wave signal to pass is provided between the connection position of the second communication unit and the input circuit. Thereby, in the input circuit, the reading error of the rectangular wave signal can be prevented, and the waveform dullness can be improved.

  According to the present invention, even when a communication circuit other than the control pilot communication circuit is connected to the control pilot line, it is possible to reliably transmit and receive the control pilot signal between the output circuit and the input circuit.

1 is a block diagram illustrating an example of a configuration of a communication system according to a first embodiment. It is explanatory drawing which shows an example of the waveform of the control pilot signal received with an input circuit. It is explanatory drawing which shows an example of the waveform of the control pilot signal received with an input circuit. It is explanatory drawing which shows an example of the waveform of the control pilot signal received with an input circuit. It is explanatory drawing which shows an example of the waveform of the control pilot signal received with an input circuit. It is explanatory drawing which shows an example of the transmission characteristic of a control pilot signal. It is explanatory drawing which shows an example of the transmission characteristic of a control pilot signal. It is explanatory drawing which shows an example of the transmission characteristic between communication parts. It is explanatory drawing which shows an example of the transmission characteristic between communication parts. 6 is a block diagram illustrating an example of a configuration of a communication system according to a second embodiment. FIG. FIG. 10 is a block diagram illustrating an example of a configuration of a communication system according to a third embodiment. It is a circuit diagram which shows an example of a structure of a low-pass filter. It is explanatory drawing which shows an example of the waveform of the control pilot signal received with an input circuit. It is explanatory drawing which shows an example of the transmission characteristic of a control pilot signal.

(Embodiment 1)
DESCRIPTION OF EMBODIMENTS Hereinafter, a communication system according to an embodiment of the present invention will be described based on the drawings. FIG. 1 is a block diagram showing an example of the configuration of the communication system according to the first embodiment. As shown in FIG. 1, a vehicle such as an electric vehicle or a hybrid vehicle and a power feeding device are electrically connected via an inlet 5 (also referred to as “power feeding port” or “connector”). The power supply apparatus includes an AC power source 6. The AC power supply 6 is electrically connected to the vehicle charger 7 through the power supply line 1 (ACL) and the power supply line 2 (ACN). A battery (secondary battery) 8 is connected to the charger 7.

  Thus, AC power can be supplied to the vehicle by connecting a plug (not shown) connected to the charging cable from the power supply device to the inlet 5, and the battery 8 mounted on the vehicle can be charged. it can.

  The communication system according to the present embodiment includes a communication device 10 provided in a power supply device, a communication device 50 provided in a vehicle, and the like.

  The communication device 10 includes an output circuit 20 that outputs a rectangular wave signal (also referred to as a “control pilot signal”) having a predetermined frequency, a communication unit 30 that performs communication other than control pilot communication as a first communication unit, and a series resonance circuit. 31 and the like.

  The communication device 50 includes an input circuit 60 to which a control pilot signal is input, a communication unit 70 for performing communication other than control pilot communication, a series resonance circuit 71, and the like as a second communication unit.

  The output circuit 20 includes a voltage generation source 21 that generates a rectangular wave signal (control pilot signal), a resistor 22, a capacitor 23, a microcomputer 24, a buffer 25, and the like. For example, the voltage source 21 generates a rectangular wave signal (control pilot signal) having a frequency of 1 kHz and a peak value of ± 12V. The duty ratio of the control pilot signal is 20%, for example, but is not limited to this. The rectangular wave signal is a signal whose duty ratio can be changed from 0 to 100%, and includes a constant voltage of ± 12 V, for example. The output circuit 20 sends a control pilot signal to the input circuit 60 provided in the vehicle via the resistor 22.

  The capacitor 23 is provided in order to reduce noise generated in the output circuit 20, for example. The value of the resistor 22 is, for example, 1.0 kΩ, and the capacitance of the capacitor 23 is, for example, 2.2 nF, but the numerical value is not limited thereto.

  The buffer 25 has a function as a voltage detector that detects the output voltage of the output circuit 20, detects the voltage across the capacitor 23, and outputs the detection result to the microcomputer 24.

  The microcomputer 24 has a function as an adjustment unit that adjusts the rectangular wave signal generated by the voltage generation source 21. As a result, the output circuit 20 can output a rectangular wave signal (control pilot signal) having a constant voltage of ± 12 V and an arbitrary duty ratio (greater than 0 and smaller than 100) and a peak value of ± 12 V. it can.

  The input circuit 60 includes a capacitor 61, a diode 62, a buffer 63, a microcomputer 64, a resistance unit 65, and the like. The buffer 63 detects the voltage Vout across the resistance unit 65 and outputs it to the microcomputer 64. Note that the voltage across the capacitor 61 may be detected instead of the voltage across the resistor 65.

  The resistance unit 65 includes a plurality of resistors and an open / close switch, and can change (adjust) the resistance value by opening / closing the open / close switch by a signal from the microcomputer 64.

  The microcomputer 64 has a function as an adjustment unit that adjusts the resistance value of the resistance unit 65 in order to change the voltage Vout of the resistance unit 65. That is, the microcomputer 64 changes the resistance value of the resistance unit 65 in order to change the voltage Vout according to the state of the vehicle (for example, a state related to charging). Depending on the value of the voltage Vout, the power supply device and the vehicle can detect a state related to charging.

  For example, when the voltage Vout is 12 V, the vehicle charging plug is not connected. Further, when the voltage Vout is 9V, the resistance value of the resistance portion 65 is set to 2.74 kΩ, and the charging plug of the vehicle is connected to indicate a state of waiting for charging. Further, when the voltage Vout is 6V, the resistance value of the resistance unit 65 is set to 882Ω, indicating a state during charging. Further, when the voltage Vout is 3V, the resistance value of the resistance unit 65 is set to 246Ω, indicating that charging is in progress and the charging place needs to be ventilated.

  The capacitor 61 is provided, for example, to reduce noise that enters the input circuit 60. The resistance value of the resistor unit 65 is, for example, about 2.74 kΩ, 882Ω, and 246Ω, and the capacitance of the capacitor 61 is, for example, 1.8 nF, but the numerical value is not limited to these.

  The output circuit 20 and the input circuit 60 are electrically connected via a plurality of signal lines (control pilot line 4 and ground line 3). The ground wire 3 can also be regarded as a control pilot line.

  The communication unit 30 and the communication unit 70 superimpose communication signals of a required communication band on a plurality of signal lines (control pilot line 4 and ground line 3) provided between the output circuit 20 and the input circuit 60. Communicate. Information transmitted / received between the communication unit 30 and the communication unit 70 includes, for example, information related to a vehicle ID, information related to charge control (start or end of charge, etc.), charge amount management (rapid charge, charge amount notification, etc.) Related to the control pilot signal, such as information related to charging, management of charging, information related to updating of navigation, and the like.

  The communication unit 30 and the communication unit 70 include, for example, a modulation circuit and a demodulation circuit using an FSK (Frequency Shift Keying) method. The communication band of communication performed by the communication unit 30 and the communication unit 70 is, for example, 1.75 MHz to 1.8 MHz.

  A series circuit of a series resonance circuit 31 and a communication unit 30 is connected between the control pilot line 4 and the ground line 3 on the output side of the output circuit 20, and the communication unit 30 is connected via the series resonance circuit 31. A communication signal is superimposed on the control pilot line 4 and a communication signal on the control pilot line 4 is received.

  A series circuit of a series resonance circuit 71 and a communication unit 70 is connected between the control pilot line 4 on the input side of the input circuit 60 and the ground line 3, and the communication unit 70 is connected via the series resonance circuit 71. A communication signal is superimposed on the control pilot line 4 and a communication signal on the control pilot line 4 is received.

  That is, the communication unit 30 and the communication unit 70 are directly connected between the signal lines via the series resonance circuits 31 and 71, and perform communication by superimposing a communication signal on the signal line. Such a system that does not use a transformer can be referred to as a direct system or a capacitive system.

  The series resonant circuit 31 is a series circuit of a resistor 311, a capacitor 312 and an inductor 313. Similarly, the series resonance circuit 71 is a series circuit of a resistor 711, a capacitor 712, and an inductor 713. The values of the capacitors 312, 712 and the inductors 313, 713 can be set so that the resonance frequency of the series resonance circuit matches the communication band of the communication unit 30 and the communication unit 70. A method for setting each value of capacitors 312, 712 and inductors 313, 713 will be described later.

  The series resonant circuits 31 and 71 block higher harmonics than the ninth harmonic whose fundamental wave is the frequency of a predetermined rectangular wave generated by the output circuit 20. The frequency of the predetermined rectangular wave is, for example, 1 kHz. This prevents the harmonic component of the rectangular wave signal (control pilot signal) having a predetermined frequency generated by the output circuit 20 from propagating to the communication units 30 and 70, thereby preventing the rectangular wave signal from being distorted. Even when a communication circuit other than the control pilot communication circuit is connected to the control pilot line, signal transmission / reception between the output circuit 20 and the input circuit 60 can be reliably performed.

  Furthermore, the harmonics of the 15th harmonic or higher with the frequency of a predetermined rectangular wave generated by the output circuit 20 generated by the series resonant circuits 31 and 71 as a fundamental wave may be blocked. As a result, the rectangular wave signal is distorted by blocking the propagation of higher-order harmonic components of the rectangular wave signal (control pilot signal) of the predetermined frequency generated by the output circuit 20 to the communication units 30 and 70. Even when a communication circuit other than the control pilot communication circuit is connected to the control pilot line, signal transmission / reception between the output circuit 20 and the input circuit 60 can be performed more reliably.

  2 to 5 are explanatory diagrams showing examples of waveforms of control pilot signals received by the input circuit 60. FIG. In the figure, the horizontal axis indicates time, and the vertical axis indicates voltage. The voltage is the voltage Vout illustrated in FIG.

  The example of FIG. 2 shows a case where the capacitances Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 are 8.2 nF, and the rise time Tr (voltage from 10% to 90%) of the control pilot signal received by the input circuit 60. % Time) is 40 μs. In this case, since the control pilot signal received by the input circuit 60 is distorted, the probability that signals cannot be transmitted / received between the output circuit 20 and the input circuit 60 increases.

  The example of FIG. 3 shows a case where the capacitances Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 are 1.0 nF, and the rise time Tr of the control pilot signal received by the input circuit 60 is 14 μs. In this case, distortion is reduced in the control pilot signal received by the input circuit 60, and signal transmission / reception between the output circuit 20 and the input circuit 60 can be reliably performed.

  The example of FIG. 4 shows a case where the capacitances Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 are 0.1 nF, and the rise time Tr of the control pilot signal received by the input circuit 60 is 10 μs. Also in this case, distortion is reduced in the control pilot signal received by the input circuit 60, and signal transmission / reception between the output circuit 20 and the input circuit 60 can be performed reliably.

  The example of FIG. 5 shows a case where the series resonance circuits 31 and 71 and the communication units 30 and 70 are not provided, and the rise time Tr of the control pilot signal received by the input circuit 60 is 10 μs. Although the series resonant circuits 31 and 71 and the communication units 30 and 70 are not provided, the rise time Tr is 10 μs because of the stray capacitance existing between the output circuit 20, the signal lines 3 and 4, and the input circuit 60. However, there is no practical problem.

  As described above, distortion of the control pilot signal received by the input circuit 60 is at a level that causes no practical problem by setting the capacitance Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 to a predetermined value (for example, 1 nF) or less. Can be made as small as possible.

  When the capacitances Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 are increased (for example, 8.2 nF), the impedance to a high frequency (for example, a harmonic component of the frequency of the rectangular wave signal) decreases, and the output circuit 20 Propagates to the communication units 30 and 70, so that the rectangular wave signal is distorted. By reducing the capacitance Cp of the capacitors 312 and 712 (for example, 1 nF or less), the rectangular wave signal is prevented from propagating to the communication units 30 and 70, and the distortion of the rectangular wave signal is prevented from increasing. it can.

  The series resonant circuits 31 and 71 have a pass band of 1.75 MHz to 1.8 MHz so as to match the communication band of the communication units 30 and 70. In order to set the resonance frequency of the series resonance circuits 31, 71, the values of the capacitor and the inductor can be arbitrarily set in accordance with the pass band. However, when a communication circuit is connected to the control pilot line, distortion of the control pilot signal occurs when the capacitor and the inductor are set to arbitrary values. That is, in the conventional technique, even if the combination of the capacitor and inductor values for obtaining the desired resonance frequency can be selected, the distortion of the control pilot signal increases after obtaining the desired resonance frequency. In order to prevent this, it was unclear what value should be adopted.

  Therefore, the series resonant circuits 31, 71 are arranged so that a required resonant frequency (pass band) is obtained after fixing the capacitance Cp of the capacitors 312 and 712 of the series resonant circuits 31, 71 to a predetermined value (for example, 1 nF) or less. By setting the inductance Lp of the inductors 313 and 713, the resonance frequency can be shifted while preventing the distortion of the control pilot signal, and the required pass band of 1.75 MHz to 1.8 MHz can be realized. Note that the predetermined value of the capacitance Cp of the capacitors 312 and 712 is not limited to 1 nF.

  6 and 7 are explanatory diagrams illustrating an example of transmission characteristics of the control pilot signal. 6 and 7, the horizontal axis indicates the frequency, and the vertical axis indicates the voltage. The voltage is the voltage Vout illustrated in FIG.

  In the example of FIG. 6, the capacitances Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 are 8.2 nF, and the inductance Lp of the inductors 313 and 713 is 1.0 μH, which corresponds to the example of FIG. is there. As shown in FIG. 6, the frequency at which the voltage Vout decreases by 3 dB is about 9 kHz.

  In the example of FIG. 7, the capacitances Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 are 1.0 nF, and the inductance Lp of the inductors 313 and 713 is 8.2 μH, which corresponds to the example of FIG. is there. As shown in FIG. 7, the frequency at which the voltage Vout decreases by 3 dB is about 30 kHz.

  As can be seen from FIGS. 6 and 7, by reducing the capacitance Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71, the impedance at low frequency is increased, and the harmonic component of the control pilot signal is changed to the communication unit 30. , 70 (including ECU and the like), and as a result, distortion of the control pilot signal or dull rise and dull fall can be prevented.

  8 and 9 are explanatory diagrams illustrating an example of transmission characteristics between the communication units 30 and 70. FIG. 8 and 9, the horizontal axis indicates the frequency, and the vertical axis indicates the attenuation factor in the control pilot line 4 between the communication units 30 and 70, that is, the transmission path attenuation (voltage drop). 8 and 9 show transmission characteristics when the resonance frequency of the series resonance circuits 31 and 71 is 1.8 MHz.

  In the example of FIG. 8, the capacitances Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 are 8.2 nF, and the inductance Lp of the inductors 313 and 713 is 1.0 μH, which corresponds to the examples of FIGS. To do. As can be seen from FIG. 8, the transmission characteristic of −8 dB is shown in the vicinity of the 1.8 MHz band.

  In the example of FIG. 9, the capacitances Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 are 1.0 nF, the inductance Lp of the inductors 313 and 713 is 8.2 μH, and the examples of FIGS. It corresponds to. As can be seen from FIG. 9, the transmission characteristic of −5 dB is shown in the vicinity of the 1.8 MHz band.

  As can be seen from FIGS. 8 and 9, even if the capacitances Cp of the capacitors 312 and 712 of the series resonant circuits 31 and 71 are changed, the transmission characteristics are almost the same.

(Embodiment 2)
In the first embodiment described above, the example using the series resonance circuit has been described, but the present invention is not limited to this.

  FIG. 10 is a block diagram showing an example of the configuration of the communication system according to the second embodiment. A difference from the first embodiment is that coupling capacitors 32 and 72 and transformers 33 and 73 are provided in place of the series resonant circuits 31 and 71.

  That is, a series circuit of coupling capacitors 32 and 32 and a transformer 33 is connected between the control pilot line 4 on the output side of the output circuit 20 and the ground line 3, and the communication unit 30 connects the transformer 33. The communication signal is superimposed on the control pilot line 4 via the control pilot line 4 and the communication signal on the control pilot line 4 is received.

  In addition, a series circuit of coupling capacitors 72 and 72 and a transformer 73 is connected between the control pilot line 4 on the input side of the input circuit 60 and the ground line 3, and the communication unit 70 connects the transformer 73. The communication signal is superimposed on the control pilot line 4 via the control pilot line 4 and the communication signal on the control pilot line 4 is received.

  That is, the communication unit 30 and the communication unit 70 perform communication by connecting the transformers 33 and 73 between the signal lines and superimposing a voltage on the signal lines. Such a method can be referred to as a line-to-line communication method. Note that parts similar to those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  Also in the second embodiment, by making the capacitances of the coupling capacitors 32 and 72 equal to or less than a predetermined value, it is possible to prevent distortion of the control pilot signal or dull rise of the control as in the first embodiment.

(Embodiment 3)
The third embodiment has a configuration in which a low-pass filter is interposed in the control pilot line in the first embodiment. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the first embodiment is referred to and detailed description thereof is omitted.

  FIG. 11 is a block diagram illustrating an example of a configuration of a communication system according to the third embodiment. In the third embodiment, a low-pass filter 90 is interposed in the control pilot line 4 connected to the input circuit 50. The low-pass filter 90 is located between the connection position of the communication unit 70 and the input circuit 50, and passes a signal having a frequency lower than a predetermined frequency, that is, a rectangular wave signal having a predetermined frequency such as a control pilot signal. Moreover, since it becomes a high impedance with respect to a communication signal of a band of 1.75 MHz to 1.8 MHz, etc., it also functions as a blocking means for blocking the communication signal.

  FIG. 12 is a circuit diagram showing an example of the configuration of the low-pass filter. As shown in FIG. 12, the low-pass filter 90 is configured as a circuit in which, for example, a coil having an inductance of 1.5 mH and a 1.0 kΩ resistor are arranged in parallel.

  FIG. 13 is an explanatory diagram showing an example of the waveform of the control pilot signal received by the input circuit 60. In the figure, the horizontal axis indicates time, and the vertical axis indicates voltage. The voltage is the voltage Vout illustrated in FIG. 1 according to the first embodiment.

  In FIG. 13, the solid line indicates the waveform when the low-pass filter 90 is provided, and the broken line indicates the waveform when the low-pass filter 90 is not provided for comparison. As shown in FIG. 13, it is clear that the low-pass filter 90 is provided to improve the dullness of the control pilot signal, which can be expected to reduce the reading error.

  FIG. 14 is an explanatory diagram showing an example of transmission characteristics of the control pilot signal. In FIG. 14, the horizontal axis indicates the frequency, and the vertical axis indicates the voltage. The voltage is the voltage Vout illustrated in the first embodiment.

  In FIG. 14, the solid line indicates the waveform when the low-pass filter 90 is provided, and the broken line indicates the waveform when the low-pass filter 90 is not provided for comparison. As shown in FIG. 14, it can be read that the low-pass filter 90 is provided so that the attenuation is large in the frequency band of 200 kHz or higher and the communication signal is prevented from being mixed. By preventing communication signals from being mixed, effects such as suppression of reading errors are expected.

  In the third embodiment, the configuration in which the control pilot line is provided with the low-pass filter is shown. However, the present invention is not limited to this, and the ground line may be provided with the low-pass filter. A low pass filter may be interposed in both the pilot line and the ground line.

  Further, not only the vehicle side but also a low-pass filter may be provided on the control pilot line or the ground line on the power feeding apparatus side, or both.

  The disclosed embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

3 Grounding wire (control pilot wire)
4 Control pilot line 10, 50 Communication device 20 Output circuit 21 Voltage generation source 22 Resistance 23 Capacitor 24 Microcomputer 25 Buffer 30, 70 Communication unit 31, 71 Series resonance circuit 311, 711 Resistance 312, 712 Capacitor 313, 713 Inductor 32, 72 Coupling capacitors 33, 73 Transformer 60 Input circuit 61 Capacitor 62 Diode 63 Buffer 64 Microcomputer 65 Resistor 90 Low pass filter

Claims (8)

An output circuit that is provided in a power supply device that supplies power to the vehicle and outputs a rectangular wave signal having a predetermined frequency; and a rectangular wave that is provided in the vehicle and connected to the output circuit by a plurality of signal lines and output from the output circuit. A communication system that communicates between the vehicle and the power feeding device by superimposing a communication signal on the signal line.
A first communication unit that is provided in the power supply device and is connected between the signal lines via a first series resonance circuit, and transmits and receives communication signals;
A second communication unit that is provided in the vehicle and is connected between the signal lines via a second series resonant circuit, and transmits and receives communication signals;
The first and second series resonant circuits are:
A communication system characterized by blocking a higher harmonic than a ninth higher harmonic having the predetermined frequency as a fundamental wave. The first and second series resonant circuits are:
2. The communication system according to claim 1, wherein higher harmonics of the 15th harmonic or higher having the predetermined frequency as a fundamental wave are cut off. The first and second series resonant circuits are:
The communication system according to claim 1, wherein the communication system has a passband of 1.75 MHz to 1.8 MHz. The vehicle is
A low-pass filter that is interposed in the signal line and passes the rectangular wave signal;
The low-pass filter is
The communication system according to any one of claims 1 to 3, wherein the communication system is located between a connection position of the second communication unit and an input circuit. In a communication device including an output circuit that outputs a rectangular wave signal of a predetermined frequency via a plurality of signal lines,
A communication unit that is connected between the signal lines via a series resonance circuit and that transmits and receives communication signals by superimposing communication signals on the signal lines;
The series resonant circuit is:
A communication apparatus that cuts off a harmonic higher than a ninth harmonic having the predetermined frequency as a fundamental wave. In a communication device including an output circuit that outputs a rectangular wave signal of a predetermined frequency via a plurality of signal lines,
A communication unit that is connected between the signal lines via a series resonance circuit and that transmits and receives communication signals by superimposing communication signals on the signal lines;
The series resonant circuit is:
A communication apparatus that cuts off harmonics of the fifteenth harmonic or higher having the predetermined frequency as a fundamental wave. In a vehicle including an input circuit to which a rectangular wave signal having a predetermined frequency is input via a plurality of signal lines,
A communication unit that is connected between the signal lines via a series resonance circuit and that transmits and receives communication signals by superimposing communication signals on the signal lines;
The series resonant circuit is:
A communication apparatus that cuts off a harmonic higher than a ninth harmonic having the predetermined frequency as a fundamental wave. In a vehicle including an input circuit to which a rectangular wave signal having a predetermined frequency is input via a plurality of signal lines,
A communication unit that is connected between the signal lines via a series resonance circuit and that transmits and receives communication signals by superimposing communication signals on the signal lines;
The series resonant circuit is:
A communication apparatus that cuts off harmonics of the fifteenth harmonic or higher having the predetermined frequency as a fundamental wave.

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