JP2013059176A - Communication system, vehicle, and charging stand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a communication line in a charging cable to perform excellent communication between a vehicle and a charging stand.SOLUTION: A vehicle 1 or a charging stand 3 transmits an in-band signal superposed on a communication line 32 in a charging cable 8 to transmit and receive a CPLT signal, during only either a high-level period or a low-level period of the CPLT signal whose level changes according to the state of charging control of a battery 2 mounted on the vehicle 1.

Description

  The present invention relates to a communication system between a vehicle and a charging station.

  In recent years, vehicles such as plug-in hybrid vehicles and electric vehicles are rapidly developing, and a charging stand for charging a battery mounted on the vehicle is expected to spread. In such an environment, the vehicle and the charging station can communicate with each other such as transmitting the battery charge amount or vehicle identification information from the vehicle to the charging station, or transmitting charging information from the charging station to the vehicle. Communication needs are expected to increase.

  As a communication system between a vehicle and a charging station, for example, a control pilot signal (CPLT (Control Pilot) signal) indicating whether or not a charging cable is connected or ready for charging is transmitted via a communication line in the charging cable. CPLT communication transmitted and received between a vehicle and a charging station is known.

Japanese Patent Application Laid-Open No. 2009-100569 Japanese Patent Laid-Open No. 07-038474

  An object of this invention is to perform favorable communication between a vehicle and a charging stand using the communication line in a charging cable.

  The communication system of the present invention is a communication system between a vehicle and a charging station, and the vehicle or the charging station has a CPLT signal whose level changes according to a state of charge control of a battery mounted on the vehicle. Only in the high level period or only in the low level period, the Inband signal superimposed on the communication line in the charging cable for transmitting and receiving the CPLT signal is transmitted.

  As a result, even if the impedance of the active element that varies the amplitude of the Inband signal due to a change in the level of the CPLT signal varies, the Inband signal is less likely to be affected by the impedance variation of the active element. Variations in amplitude can be suppressed. Further, the Inband signal can be transmitted while avoiding the influence of noise generated in the CPLT signal at the timing when the CPLT signal changes from the low level to the high level or when the CPLT signal changes from the high level to the low level. Therefore, good communication can be performed between the vehicle and the charging station using the communication line in the charging cable.

  ADVANTAGE OF THE INVENTION According to this invention, a vehicle and a charging stand can perform favorable communication using the communication line in a charging cable.

It is a figure which shows the communication system of embodiment of this invention. It is a flowchart which shows an example of operation | movement of a control circuit. It is a figure which shows an example of the packet structure after dividing | segmenting an Inband signal. It is a figure which shows an example of the transmission timing of an Inband signal. It is a figure which shows an example of the CPLT signal at the time of charge.

FIG. 1 is a diagram showing a communication system according to an embodiment of the present invention.
The communication system shown in FIG. 1 includes a charging stand 3 that supplies power to the vehicle 1 in order to charge a battery 2 mounted on the vehicle 1 (for example, a plug-in hybrid vehicle or an electric vehicle).

  The charging stand 3 includes an AC power supply 4, a charging circuit 5, a CPLT communication device 6, an Inband communication device 7, and a charging cable 8. Note that one end of the charging cable 8 is connected to the charging circuit 5, and a connector 9 is provided at the other end of the charging cable 8.

The CPLT communication device 6 includes a level detection circuit 10, a CPLT signal output circuit 11, and a control circuit 12 (for example, a microcomputer).
The inband communication device 7 includes a modem 13 and a control circuit 14 (for example, a microcomputer).

The modem 13 includes a communication circuit 15, a transformer 16, and capacitors 17 and 18.
The vehicle 1 includes a battery 2, a charger 19, a CPLT communication device 20, and an Inband communication device 21.

  The CPLT communication apparatus 20 includes a level detection circuit 22, resistors 23 to 25, switches 26 and 27, a rectifying diode 28, and a control circuit 29 (for example, a microcomputer).

The inband communication device 21 includes a modem 13 and a control circuit 14 in the same manner as the inband communication device 7.
For example, when the user connects the connector 9 to the charging inlet on the vehicle 1 side, the charging circuit 5 on the charging stand 3 side and the charger 19 on the vehicle 1 side are connected to each other via the power line 31 in the charging cable 8. Is done. In addition, the CPLT communication device 6 on the charging station 3 side and the CPLT communication device 20 on the vehicle 1 side are connected to each other via the communication line 32 in the charging cable 8, and on the charging station 3 side via the communication line 32. The inband communication device 7 and the inband communication device 21 on the vehicle 1 side are connected to each other.

  During charging, the charging circuit 5 of the charging stand 3 supplies power obtained from the AC power supply 4 to the charger 19 of the vehicle 1 via the power line 31. The charger 19 charges the battery 2 with electric power supplied from the charging stand 3.

When the connector 9 is connected to the charging inlet on the vehicle 1 side, the CPLT communication devices 6 and 20 transmit and receive a CPLT signal to each other via the communication line 32.
The CPLT signal at the time of charging the battery 2 mounted on the vehicle 1 is, for example, as shown in FIG.

  First, when the connector 9 is connected to the charging inlet on the vehicle 1 side (time t1), the level of the CPLT signal on the communication line 32 (vehicle side) (the voltage of the communication line 32 in the charging cable 8) is 0 [V. ] To V1 (for example, +12 [V]). Then, the charger 19 of the vehicle 1 is activated.

Next, when activation of the charger 19 of the vehicle 1 is completed (time t2), the vehicle 1 changes the level of the CPLT signal from V1 to V2 (for example, +9 [V]).
Next, when the level of the CPLT signal changes from V1 to V2, the charging stand 3 has a duty that indicates the rated current of the AC power supply 4 with an amplitude of −V1 (for example, −12 [V]) to V2. The CPLT signal is oscillated so as to be a rectangular wave. The vehicle 1 prepares for charging based on the duty of the CPLT signal at this time.

  Next, when the preparation for charging on the vehicle 1 side is completed (time t3), the vehicle 1 changes the magnitude of the amplitude of the CPLT signal to −V1 to V3 (for example, +6 [V]). Then, electric power is supplied from the charging stand 3 to the vehicle 1 through the electric power line 31 in the charging cable 8, and charging of the battery 2 is started.

When charging of the battery 2 is completed (time t4), the charging station 3 stops the oscillation of the CPLT signal. Moreover, the vehicle 1 returns the level of the CPLT signal to V1.
That is, the control circuit 12 of the CPLT communication device 6 of the charging station 3 is based on the voltage of the communication line 32 (the level of the CPLT signal) detected by the level detection circuit 10 or the charge end notification sent from the charging circuit 5. Thus, the operation of the CPLT signal output circuit 11 and the charging circuit 5 is controlled. The CPLT signal output circuit 11 oscillates the voltage of the communication line 32 according to an instruction from the control circuit 12.

  For example, as shown in FIG. 5, when the control circuit 12 receives a detection result indicating that the voltage of the communication line 32 has changed from V1 to V2 from the level detection circuit 10 (time t2), the amplitude is −V1. An instruction to oscillate the voltage of the communication line 32 is sent to the CPLT signal output circuit 11 so as to obtain a duty rectangular wave indicating the rated current of the AC power supply 4 at ˜V2. When receiving an instruction to oscillate the voltage of the communication line 32, the CPLT signal output circuit 11 oscillates the voltage of the communication line 32. Further, when the control circuit 12 receives from the level detection circuit 10 a detection result indicating that the amplitude of the voltage of the communication line 32 has changed from −V1 to V2 to −V1 to V3, the charging circuit 5 Send to. When the power supply permission is sent, the charging circuit 5 supplies the power obtained from the AC power source 4 to the charger 19 via the power line 31. In addition, when no current is drawn from the charger 19 and a charging end notification is sent from the charging circuit 5 (time t4), the control circuit 12 issues an instruction to stop the oscillation of the voltage of the communication line 32 to the CPLT signal. This is sent to the output circuit 11. When receiving an instruction to stop the oscillation of the voltage of the communication line 32, the CPLT signal output circuit 11 stops the oscillation of the voltage of the communication line 32.

  Further, the control circuit 29 of the CPLT communication device 20 of the vehicle 1 switches the switches 26 and 27 based on the voltage of the communication line 32 detected by the level detection circuit 22 and the charge preparation completion notification sent from the charger 19. Is turned on and off, and the operation of the charger 19 is controlled.

  For example, as shown in FIG. 5, when the voltage of the communication line 32 changes from 0 [V] to V1 (time t1), the control circuit 29 sends an activation instruction to the charger 19. When the charger 19 receives the activation instruction, the charger 19 performs self activation. In addition, when the activation of the charger 19 is completed (time t2), the control circuit 29 turns the switch 26 from on to change the voltage applied to the communication line 32 from V1 to V2. When the control circuit 29 receives a notification from the charger 19 that the preparation for charging based on the duty of the oscillation voltage of the communication line 32 is completed (time t3), the control circuit 29 turns the switch 27 from off to on to oscillate the communication line 32. The amplitude of the voltage is changed from -V1 to V2 to -V1 to V3. Further, when the control circuit 29 receives from the charger 19 that the charging is completed (time t4), the control circuit 29 controls the switches 26 and 27 from on to off, respectively, and returns the voltage of the communication line 32 to V1.

  When the connector 9 is connected to the charging inlet on the vehicle 1 side, the Inband communication devices 7 and 21 transmit and receive Inband signals to each other via the communication line 32. As the Inband signal, for example, information indicating the charge amount of the battery 2 (for example, SOC (State Of Charge), identification information of the vehicle 1, or billing information according to the amount of power supplied to the vehicle 1) is considered. The frequency of the Inband signal is higher than the frequency (1 kHz) of the CPLT signal at the time of oscillation, for example, about several to several tens of MHz.

  That is, the modem 13 modulates the Inband signal transmitted from the control circuit 14 from digital to analog in the communication circuit 15 and then superimposes the Inband signal on the communication line 32 via the transformer 16 and the capacitors 17 and 18. The modem 13 extracts the Inband signal from the signal obtained from the communication line 32 via the transformer 16 and the capacitors 17 and 18 in the communication circuit 15, and then demodulates the Inband signal from analog to digital to the control circuit 14. send.

Thereby, an Inband signal can be transmitted and received between the Inband communication device 7 of the charging station 3 and the Inband communication device 21 of the vehicle 1.
By the way, when the diode 28 as an active element connected to the communication line 32 in the charging cable 8 is turned on and off due to a change in the level of the CPLT signal and the impedance of the diode 28 varies, the impedance of the diode 28 varies. Thus, the magnitude of the amplitude of the Inband signal varies. For example, the diode 28 is turned on when the CPLT signal is at a high level (for example, V1, V2, or V3 shown in FIG. 5), and is turned off when the CPLT signal is at a low level (for example, -V1 shown in FIG. 5). In this case, when the diode 28 is turned on and the impedance of the diode 28 is lowered, the current flowing to the Inband communication devices 7 and 21 side is reduced and the amplitude of the Inband signal is reduced. When the diode 28 is turned off and the impedance of the diode 28 is increased, the current flowing to the Inband communication devices 7 and 21 side is increased, and the amplitude of the Inband signal is increased. Thus, if the magnitude of the amplitude of the Inband signal fluctuates with the change in the level of the CPLT signal, it becomes impossible to obtain an Inband signal of a desired level between the vehicle 1 and the charging station 3. There is a risk of hindering good Inband communication.

  Therefore, a feature of the communication system of the present embodiment is that the Inband communication devices 7 and 21 transmit the Inband signal only in the high level period or the low level period of the CPLT signal. In the communication system of the present embodiment, the diode 28 is provided on the vehicle 1 side as an active element whose impedance varies with a change in the level of the CPLT signal. The active element (such as a diode or a transistor) is a charging stand. It may be provided on the third side. The communication circuit 15 in the modem 13 is connected to the communication line 32 in a configuration using the transformer 16 and the capacitors 17 and 18, but this may be a configuration using only a capacitor, a configuration using only a transformer, Other elements may be used in combination.

  FIG. 2 is a flowchart showing the operation of the control circuit 14 of the Inband communication device 7 at the time of Inband signal transmission. The operation of the control circuit 14 of the Inband communication device 21 at the time of Inband signal transmission is the same as the flowchart shown in FIG.

  First, the control circuit 14 obtains the duty of the CPLT signal based on the level of the CPLT signal detected by the level detection circuit 10 of the CPLT communication device 6 (or the level detection circuit 22 of the CPLT communication device 20) (S1). It is determined whether or not the duty of the CPLT signal is larger than 50 [%] (S2). For example, when the cycle of the CPLT signal is 1 [ms] and the high level period of the CPLT signal is 0.5 [ms], the control circuit 14 sets (0.5 / 1) × 100 = 50 as the duty of the CPLT signal. Calculate [%]. Further, the control circuit 14 of the Inband communication device 7 may directly acquire the duty of the CPLT signal from the control circuit 12 of the CPLT communication device 6.

  When it is determined that the duty of the CPLT signal is larger than 50 [%] (Yes in S2), the control circuit 14 determines the high-level period of the CPLT signal as the transmission period of the Inband signal (S3), When it is determined that the duty is 50% or less (No in S2), the control circuit 14 determines the low level period of the CPLT signal as the transmission period of the Inband signal (S4).

  Next, the control circuit 14 transmits the Inband signal based on the data size (for example, the number of bits) of the Inband signal and the communication parameter (for example, the bit rate (the number of bits that can be transmitted per unit time)). (S5). For example, the control circuit 14 obtains the time required to transmit the Inband signal by dividing the number of bits of the Inband signal by the bit rate.

  Next, the control circuit 14 divides the Inband signal into a plurality of Inabnd signals when the time taken to transmit the Inband signal does not fit in the transmission period of the Inband signal determined in S3 or S4 (S6 is No). The Inband signal is divided into a plurality of Inabnd signals so that the transmission time of each subsequent Inabnd signal falls within the Inband signal transmission period determined in S3 or S4, respectively (S7). FIG. 3 is a diagram illustrating an example of a packet structure of an Inband signal before division or one Inabnd signal after division. The packet structure shown in FIG. 3 includes a preamble area 30, an address area 31, a division information area 32, a data area 33, and an FCS (Frame Check Sequence) area 34. The preamble area 30 includes a preamble signal indicating the beginning of a packet. The address area 31 includes a transmission destination address and a transmission source address. The division information area 32 includes a flag indicating whether the Inband signal is divided or information indicating the number of divisions of the Inband signal. The data area 33 includes data such as the above-described SOC, identification information, or billing information. When the Inband signal is divided, the information included in the data area 33 is divided. The FCS area 34 includes information for detecting a packet error.

  Next, when the CPLT signal high level period is determined to be the Inband signal transmission period in S3 (S8 is Yes), the control circuit 14 comes to a timing when the CPLT signal changes from the low level to the high level (S9 is Yes). And, S10 is Yes), the Inband signal (or one divided Inabnd signal) is transmitted from the modem 13 to the communication line 32 via the transformer 16 and the capacitors 17 and 18 (S11).

  When the Inband signal is divided into a plurality of Inabnd signals, the control circuit 14 repeatedly executes S9 to S11 until all the Inabnd signals are transmitted (S12 is Yes). For example, when the Inband signal is divided into a plurality of Inabnd signals, the control circuit 14 transmits each Inabnd signal only in the high level period of the CPLT signal, as shown in FIG. 4A.

  On the other hand, when the low-level period of the CPLT signal is determined as the transmission period of the Inband signal in S3 (S8 is No), the control circuit 14 becomes the timing when the CPLT signal changes from the high level to the low level (S13 is Yes, And, S14 is Yes), the Inband signal (or one divided Inabnd signal) is transmitted from the modem 13 to the communication line 32 via the transformer 16 and the capacitors 17 and 18 (S15).

  When the Inband signal is divided into a plurality of Inband signals, the control circuit 14 repeatedly executes S13 to S15 until all the Inabnds are transmitted (S16 is Yes). For example, when the Inband signal is divided into a plurality of Inabnd signals, the control circuit 14 transmits each Inabnd signal only in the low level period of the CPLT signal, as shown in FIG. 4B.

  Note that the control circuit 14 may, for example, inband signals (or divided Inabnd signals after division) only during the high-level period or the low-level period of the CPLT signal in the period from t2 to t3 and the period from t3 to t4 shown in FIG. Shall be sent.

  In addition, the control circuit 14 when receiving the Inband signal includes, for example, a flag indicating that the Inabnd signal is divided in the division information area 32 illustrated in FIG. 3, and is included in the division information area 32. Based on the number of divisions of the Inband signal, a plurality of Inabnd signals are received, and the received Inband signals are integrated to generate the original Inband signal.

  As described above, the communication system according to the present embodiment is configured to transmit the Inband signal only in the high-level period or only the low-level period of the CPLT signal in the Inband communication apparatuses 7 and 21, so that the level of the CPLT signal changes. Even if the impedance of the diode 28 fluctuates, the Inband signal is hardly affected by the impedance fluctuation of the diode 28. Therefore, fluctuations in the amplitude of the Inband signal can be suppressed. Further, the Inband signal can be transmitted while avoiding the influence of noise generated in the CPLT signal at the timing when the CPLT signal changes from the low level to the high level or when the CPLT signal changes from the high level to the low level. Therefore, good communication can be performed between the vehicle 1 and the charging station 3 using the communication line 32 in the charging cable 8.

  Further, in the communication system of the present embodiment, when the duty of the CPLT signal is larger than 50 [%], the Inband signal or each divided Inabnd signal is transmitted only in the high level period of the CPLT signal, and the duty of the CPLT signal is When it is 50 [%] or less, the configuration is such that the Inband signal or each divided Inabnd signal is transmitted only in the low-level period of the CPLT signal, so that the bit rate can be increased and the transmission time can be shortened.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Battery 3 Charging stand 4 AC power supply 5 Charging circuit 6 CPLT communication apparatus 7 Inband communication apparatus 8 Charging cable 9 Connector 10 Level detection circuit 11 CPLT signal output circuit 12 Control circuit 13 Modem 14 Control circuit 15 Communication circuit 16 Transformer 17 DESCRIPTION OF SYMBOLS 18 Capacitor 19 Charger 20 CPLT communication apparatus 21 Inband communication apparatus 22 Level detection circuit 23-26 Resistance 26, 27 Switch 28 Diode 29 Control circuit 31 Power line 32 Communication line

Claims (9)

A communication system between a vehicle and a charging station,
The vehicle or the charging station is charged for transmitting and receiving the CPLT signal only in a high level period or a low level period of a CPLT signal whose level changes depending on a state of charge control of a battery mounted on the vehicle. A communication system characterized by transmitting an Inband signal superimposed on a communication line in a cable. The communication system according to claim 1,
The vehicle or the charging station transmits the Inbnd signal only during a high level period of the CPLT signal when the duty of the CPLT signal is greater than 50%, and when the duty of the CPLT signal is 50% or less, An inband signal is transmitted only in a low level period of the CPLT signal. The communication system according to claim 1 or 2,
The vehicle or the charging station divides the Inbnd signal into a plurality of Inabnd signals when the transmission time of the Inband signal does not fit in the high level period or the low level period of the CPLT signal, and each of the plurality of Inabnd signals A communication system, wherein the CPLT signal is transmitted only in a high level period or only in a low level period. The vehicle in a communication system between the vehicle and a charging station,
Superposed on the communication line in the charging cable for transmitting and receiving the CPLT signal only during the high level period or only the low level period of the CPLT signal whose level changes according to the state of charge control of the battery mounted on the vehicle. A vehicle characterized by transmitting an Inband signal. The vehicle according to claim 4,
When the duty of the CPLT signal is larger than 50%, the Inbnd signal is transmitted only in the high level period of the CPLT signal. When the duty of the CPLT signal is 50% or less, the Inband signal is transmitted as the low level of the CPLT signal. A vehicle characterized by transmitting only in the level period. The vehicle according to claim 4 or 5, wherein
When the transmission time of the Inband signal does not fit in the high level period or low level period of the CPLT signal, the Inbnd signal is divided into a plurality of Inabnd signals, and each of the plurality of Inabnd signals is only in the high level period of the CPLT signal. Or a vehicle characterized by transmitting only in the low level period. The charging station in a communication system between a vehicle and a charging station,
Superposed on the communication line in the charging cable for transmitting and receiving the CPLT signal only during the high level period or only the low level period of the CPLT signal whose level changes according to the state of charge control of the battery mounted on the vehicle. A charging station characterized by transmitting an Inband signal. The charging stand according to claim 7,
When the duty of the CPLT signal is larger than 50%, the Inbnd signal is transmitted only in the high level period of the CPLT signal. When the duty of the CPLT signal is 50% or less, the Inband signal is transmitted as the low level of the CPLT signal. A charging station that transmits only during the level period. The charging stand according to claim 7 or claim 8,
When the transmission time of the Inband signal does not fit in the high level period or low level period of the CPLT signal, the Inbnd signal is divided into a plurality of Inabnd signals, and each of the plurality of Inabnd signals is only in the high level period of the CPLT signal. Or a charging station that transmits only in the low level period.

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