JP2015027181A - Non-contact charging system and battery-mounted vehicle used in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact charging system capable of charging control equivalent to a CPLT function in contact charging.SOLUTION: A non-contact charging system 100 is composed of a power supply station 10 and an electric vehicle 20. The power supply station 10 and the electric vehicle 20 comprise: control means 11, 21 for inputting and outputting a control signal (wired signal) representing a current system state on control lines 17, 29, and on top of that, radio communication means 12, 22 that convert the control signal output on the control lines 17, 29 from the control means 11, 21 into a radio signal to transmit it, and inverse-convert a received radio signal into a control signal to output it on the control lines 17, 29. Operation of the control means 11, 21 is the same as the one in conventional contact charging, and by placing the radio communication means 12, 22 between the control means 11 and 21, the control signals exchanged between the control means 11 and 21 are converted into radio signals.

Description

  The present invention relates to a contactless charging system for a battery-equipped vehicle.

  The popularization of electric vehicles (EV vehicles) driven by electric motors and plug-in hybrid vehicles (PHV vehicles) driven by the combined use of electric motors and gasoline engines has begun. These EV cars and PHV cars are equipped with a battery, and the vehicle is driven by driving a motor with electric energy stored in the battery.

  Currently, as a charging system for EV cars and PHV cars, there is generally used a system in which a power supply stand is installed in each of a plurality of parking spaces provided in a parking area and charging is performed while the vehicle is parked in the parking space. Is. As a method of supplying power from the power supply stand to the vehicle, contact charging in which the power supply stand and the vehicle are connected by a dedicated charging cable, and the principle of electromagnetic induction are used while the power supply stand and the vehicle are kept in a non-contact state. And contactless charging to supply power.

  When charging the vehicle from the power supply stand, it is necessary to exchange various control signals for charge control between the power supply stand and the vehicle. For example, “SAE J1772 standard (Non-Patent Document 1)”, which is a standard related to contact charging, defines a CPLT function for exchanging control signals between a power supply stand and a vehicle.

  In the CPLT function, a control line (control pilot line) included in a charging cable connecting the power supply stand and the vehicle is wired to connect the power supply stand and each control means of the vehicle, and a control signal (control pilot signal) is transmitted between the two. By exchanging, charge control such as confirmation of the connection state of the cable, determination of whether or not charging is possible, and abnormality detection is performed. More specifically, CPLT defines six types of states shown in FIG. 6 as states of the charging system, and a unique control signal is assigned to each state. Each control means of the power supply stand and the vehicle can detect the current system state by reading the control signal on the control line, and can transition the system state by outputting the control signal on the control line. .

“SAE Electric Vehicle and Plug in Hybrid Electric Vehicle Conductive Charge Coupler”, SAEJ1772, SAE International, October 2012

  In contact charging where the power supply stand and the vehicle are connected by a charging cable as described above, control signals can be exchanged by wired communication by including a control line in the charging cable, but contactless charging without using a charging cable In this case, it is necessary to exchange control signals between the power supply stand and the vehicle by wireless communication. Therefore, in non-contact charging, the CPLT function defined on the premise of wired communication cannot be used.

  This invention was made in order to solve such a subject, and it aims at providing the non-contact charge system which can perform charge control equivalent to the CPLT function in contact charge.

  In order to solve the above-described problems, a non-contact charging system according to the present invention is a non-contact charging system that charges a battery-equipped vehicle from a power feeding stand, and each of the power feeding stand and the battery-equipped vehicle has a charge control. Control means for inputting / outputting a wired signal (control signal) for transmission, and a wired signal output from the control means is converted to a wireless signal and transmitted, and a received wireless signal is converted back to a wired signal and controlled. Wireless communication means for outputting to the means.

  The wireless communication unit may include a holding unit that holds a wired signal obtained by inversely converting the received wireless signal, and may output the wired signal held in the holding unit to the control unit.

  The wireless communication means measures the received signal strength of the received wireless signal, and when the received signal strength is less than a predetermined threshold value, the wireless communication means discards the received wireless signal and is already held in the holding means. A signal may be output to the control means.

  The wireless communication means may output a wired signal indicating the occurrence of an abnormality to the control means when the received signal strength of the received wireless signal is less than a predetermined threshold value continuously for a predetermined number of times.

  The wired signal may be a control signal defined in the CPLT function.

  The battery-equipped vehicle according to the present invention is a battery-equipped vehicle that performs non-contact charging with a power supply stand, and is output from a control unit that inputs and outputs a wired signal for charge control, and the control unit. Wireless communication means for converting a wired signal into a wireless signal and transmitting it, and inversely converting the received wireless signal into a wired signal and outputting it to the control means.

  According to the non-contact charging system according to the present invention, charge control equivalent to the CPLT function in contact charging can be performed.

It is a figure which shows the structure of the non-contact charge system which concerns on embodiment of this invention. It is a figure which shows the structure of the electric power feeding stand and electric vehicle in the non-contact charging system which concerns on embodiment of this invention. It is a figure which shows the definition of the system state in the non-contact charge system which concerns on embodiment of this invention. It is a figure which shows the charge process in the non-contact charge system which concerns on embodiment of this invention. It is a figure which shows the charge process in the non-contact charge system which concerns on embodiment of this invention. It is a figure which shows the structure of the control message in the non-contact charge system which concerns on embodiment of this invention. It is a figure which shows the definition of the system state of the CPLT function in the contact charge which concerns on a prior art.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment.
A configuration of a non-contact charging system 100 according to an embodiment of the present invention is shown in FIG.
A power supply stand 10 is installed near the parking space S in the parking area, and a power supply coil 14 of the power supply stand 10 is installed on the ground of the parking space S. When the electric vehicle 20 is parked in the parking space S, high-frequency power is supplied to the power supply coil 14 of the power supply stand 10 after the wireless communication connection is established between the power supply stand 10 and the electric vehicle 20. Is transmitted to the power receiving coil 23 of the electric vehicle 20 to charge an in-vehicle battery (not shown). In this embodiment, only one power supply stand 10 and one electric vehicle 20 are shown, but the present invention more generally relates to a case where there are a plurality of power supply stands and a plurality of electric vehicles. Can also be applied.

  Hereinafter, the configuration of the power supply stand 10 and the electric vehicle 20 in the non-contact charging system 100 according to this embodiment will be described with reference to FIG.

(Configuration of the power supply stand 10)
First, the configuration of the power supply stand 10 will be described. The power supply stand 10 includes a control unit 11, a wireless communication unit 12, a power supply unit 13, a power supply coil 14, a vehicle detection sensor 15, and an antenna 16. Further, the control means 11 and the wireless communication means 12 are wired by a control line 17.

  The control means 11 is constituted by a microcomputer, and has been developed for performing charge control by the CPLT function in conventional contact charging. The control means 11 controls the power supply from the power supply stand 10 to the electric vehicle 20 by controlling the power supply means 13 while inputting / outputting a control signal on the control line 17.

  The wireless communication unit 12 holds a control signal (wired signal) output on the control line 17 by the control unit 11 in the buffer 18, converts the held control signal into a radio signal, and transmits the radio signal from the antenna 16. Further, the wireless communication unit 12 reversely converts the wireless signal received by the antenna 16 into a control signal (wired signal), holds the signal in the buffer 18, and outputs the held control signal onto the control line 17.

  The power supply means 13 converts AC power supplied from the power system into high frequency power having a higher frequency.

  High frequency power is supplied from the power supply means 13 to the power supply coil 14.

  The vehicle detection sensor 15 is installed on the ground of the parking space S, detects that the electric vehicle 20 is parked in the parking space S, and notifies the wireless communication means 12.

(Configuration of electric vehicle 20)
Next, the configuration of the electric vehicle 20 will be described. The electric vehicle 20 includes a control unit 21, a wireless communication unit 22, a power receiving coil 23, a charging unit 24, a battery 25, a car navigation system 26, a vehicle speed detection sensor 27, and an antenna 28. In addition, the control unit 21 and the wireless communication unit 22 are wired by a control line 29.

  The control means 21 is constituted by a microcomputer, and has been developed for performing charge control by the CPLT function in conventional contact charging. The control unit 21 controls the charging of the battery 25 by controlling the charging unit 24 while inputting / outputting a control signal on the control line 29.

  The wireless communication unit 22 holds a control signal (wired signal) output on the control line 29 by the control unit 21 in the buffer 30, converts the held control signal into a radio signal, and transmits it from the antenna 28. Further, the wireless communication means 22 converts a radio signal received by the antenna 28 into a control signal (wired signal), holds it in the buffer 30, and outputs the held control signal onto the control line 29.

  High frequency power is transmitted to the power receiving coil 23 from the power supply coil 14 of the power supply stand 10 by the principle of electromagnetic induction.

  The charging unit 24 converts the high frequency power transmitted to the power receiving coil 23 into DC power.

  The battery 25 stores the DC power output from the charging unit 24.

  The car navigation system 26 is installed in the driver's seat of the electric vehicle 20, performs information notification to the driver, receives an instruction from the driver, and notifies the control means 21.

  The vehicle speed sensor 27 detects the vehicle speed of the electric vehicle 20 and notifies the wireless communication means 22 of it.

(System state of the non-contact charging system 100)
Next, the system state in the non-contact charging system 100 according to this embodiment will be described.

  In the non-contact charging system 100, six types of system states shown in FIG. 3 are defined, and a unique control signal is assigned to each system state. The six types of system states shown in FIG. 3 are obtained by arranging the system states of the CPLT function in the conventional contact charging shown in FIG. 6 for non-contact charging, and each control signal is a CPLT shown in FIG. This is the same as the function control signal.

  The control means 11 and 21 of the power supply station 10 and the electric vehicle 20 can detect the current system state by reading the control signals on the control lines 17 and 29, and control signals on the control lines 17 and 29. Can output the system state.

(Charging process of the non-contact charging system 100)
Next, the charging process in the non-contact charging system 100 according to this embodiment will be described with reference to FIGS. 4A and 4B.

  First, in an initial state before the electric vehicle 20 is parked in the parking space S, the charging system 100 is in the State A state. At this time, the State A control signal (12 V DC signal) is held in the buffers 18 and 30 of the wireless communication means 12 and 22 of the power supply station 10 and the electric vehicle 20, and is supplied to the control lines 17 and 29. State A control signal is output.

  As shown in FIG. 4A, when the vehicle speed sensor 27 detects that the vehicle is parked in the parking space S (S101), the wireless communication means 22 of the electric vehicle 20 holds the buffer 30 in its own buffer 30. The control signal of StateA is changed to the control signal of StateB0 (DC signal of 9V), and the control signal of StateB0 is output on the control line 29, whereby the system state is changed from StateA to StateB0 (S102). The control means 21 of the electric vehicle 20 detects that the system state has changed from State A to State B0 by detecting a change in the control signal on the control line 29 (S103).

  On the other hand, when the vehicle detection sensor 15 detects that the electric vehicle 20 is parked in the parking space S (S104), the wireless communication unit 12 of the power supply station 10 controls the StateA control signal held in its own buffer 18. Is changed to a control signal of StateB0, and the control signal of StateB0 is output on the control line 17, thereby transitioning the system state from StateA to StateB (S105). The control means 11 of the power supply station 10 detects that the system state has transitioned from State A to State B0 by detecting a change in the control signal on the control line 17 (S106). Thereafter, the wireless communication means 22 of the electric vehicle 20 and the wireless communication means 12 of the power supply station 10 establish a wireless communication connection between them by exchanging a communication connection request message and a communication connection response message (S107, S108). ).

  Next, the control unit 11 of the power supply station 10 changes the system state from StateB0 to StateB1 by outputting a control signal (9V PWM signal) of StateB1 on the control line 17 (S109). Note that the duty ratio of the PWM signal at this time represents the maximum current value that can be supplied by the power supply station 10. The wireless communication means 12 of the power supply station 10 holds the control signal of StateB1 output on the control line 17 in its own buffer 18, and the control signal (packet) shown in FIG. And the message is continuously transmitted to the electric vehicle 20 at a predetermined time interval (S110).

  The control message in FIG. 5 notifies the system state transition destination and the duty ratio (%) of the PWM signal representing the current value. In the case of step S110, the bit 2 corresponding to StateB1 in the state field. 1 is set to 1 and the other bits are set to 0, and the duty ratio (%) of the PWM signal representing the maximum current value that can be supplied by the power supply station 10 is set in the current field. This message is continuously transmitted unilaterally at a predetermined time interval without waiting for a reception response from the electric vehicle 20.

  The wireless communication means 22 of the electric vehicle 20 that has received the control message reversely converts this message into a control signal for StateB1, holds the reversely converted StateB1 control signal in its own buffer 30, and then on the control line 29. (S111). The control means 21 of the electric vehicle 20 detects that the system state has transitioned from StateB0 to StateB1 by detecting a change in the control signal on the control line 29 (S112), and is represented by the duty ratio of the PWM signal. The charging condition is determined in consideration of the maximum current value (S113), and the driver is notified by the car navigation system 26 that the preparation for charging is completed (S114).

  When the driver operates the car navigation system 26 to instruct the start of charging, the control means 21 of the electric vehicle 20 outputs a StateC control signal (6V PWM signal) on the control line 29, thereby The state is changed from State B1 to State C (S115). The wireless communication means 22 of the electric vehicle 20 holds the StateC control signal output on the control line 29 in its own buffer 30, converts the held StateC control signal into a control message, and converts this message to the power supply station. Transmission is continued at predetermined time intervals toward S10 (S116). The control message at this time notifies that the system state has transitioned to State C, and designates a current value when charging the electric vehicle 20 from the power supply station 10.

  The wireless communication means 12 of the power supply station 10 that has received the control message reversely converts the message into a StateC control signal, and holds the reversely converted StateC control signal in its own buffer 18. (S117). The control means 11 of the power supply station 10 detects a change in the system state from State B1 to State C by detecting a change in the control signal on the control line 17 (S118), and is represented by the duty ratio of the PWM signal. Charging of the electric vehicle 20 is started with the current value (S119).

  When charging the electric vehicle 20 from the power supply stand 10, high frequency power is supplied from the power supply means 13 of the power supply stand 10 to the power supply coil 14, and this high frequency power is supplied to the power receiving coil 23 of the electric vehicle 20 by the principle of electromagnetic induction. Then, the battery 25 is charged via the charging means 24 (see FIG. 2).

  During this time, as shown in S120a to d of FIG. 4B, the control means 21 of the electric vehicle 20 constantly monitors the charging operation of the own vehicle, and the control line 29 is charged while the battery 25 is normally charged. The upper control signal is maintained in StateC, and the wireless communication unit 22 continues to transmit a control message corresponding to StateC to the power supply station 10 at predetermined time intervals. Similarly, the control means 11 of the power supply station 10 constantly monitors the power supply operation of its own device, and keeps the control signal on the control line 17 at State C while the power supply to the electric vehicle 20 is normally performed. The wireless communication unit 12 continues to transmit a control message corresponding to StateC to the electric vehicle 20 at a predetermined time interval. The control units 11 and 21 of the power supply station 10 and the electric vehicle 20 continue to be charged as long as the control signal obtained by reversely converting the control message transmitted from the other party is StateC.

  Although not shown in FIG. 4B, for example, when an abnormality occurs in the electric vehicle 20 during charging, the control unit 21 of the electric vehicle 20 charges the battery 25 by controlling the charging unit 24. And a StateE control signal (0V DC signal) indicating the occurrence of an abnormality is output on the control line 29, and the wireless communication means 22 transmits a control message corresponding to StateE to the power supply station 10. To do. Upon receiving this, the wireless communication unit 12 of the power supply station 10 outputs a control signal of State E on the control line 17, and the control unit 11 controls the power supply unit 13 when detecting that the system state has transitioned to State E. As a result, the power supply to the electric vehicle 20 is stopped.

  Similarly, when an abnormality occurs in the power supply station 10 during charging, the control unit 11 of the power supply station 10 stops power supply to the electric vehicle 20 by controlling the power supply unit 13 and controls StateE. The signal is output on the control line 17, and the wireless communication unit 12 transmits a control message corresponding to State E to the electric vehicle 20. The wireless communication means 22 of the electric vehicle 20 that has received this outputs a control signal of State E to the control line 29, and the control means 21 controls the charging means 24 when detecting that the system state has transitioned to State E. As a result, the charging of the battery 25 is stopped.

  Returning to FIG. 4B, when the battery 25 of the electric vehicle 20 reaches a fully charged state, the control means 21 of the electric vehicle 20 notifies the driver by the car navigation system 26 (S121), and controls the StateB1. By outputting a signal on the control line 29, the system state is changed from State C to State B1 (S122). The wireless communication means 22 of the electric vehicle 20 holds the state B1 control signal output on the control line 29 in its own buffer 30, converts the held state B1 control signal into a control message, and converts this message to the power supply stand. The transmission is continued at predetermined time intervals toward S10 (S123).

  The wireless communication means 12 of the power supply station 10 that has received the control message reversely converts the message into a control signal of StateB1, holds the control signal of StateB1 that has been reversely converted in its own buffer 18, and then on the control line 17. (S124). The control means 11 of the power supply station 10 detects a change in the control signal on the control line 17 to detect that the system state has transitioned from StateC to StateB1 (S125), and stops charging the electric vehicle 20. (S126). Thereafter, the wireless communication units 22 and 12 of the electric vehicle 20 and the power supply station 10 exchange the communication disconnection request packet and the communication disconnection response packet, thereby disconnecting the wireless communication connection between them (S127 and S128).

  When the wireless communication connection between the electric vehicle 20 and the power supply station 10 is disconnected, the wireless communication means 22 of the electric vehicle 20 changes the control signal of StateB1 held in its buffer 30 to the control signal of StateA. Then, by outputting the control signal of State A on the control line 29, the system state is changed from State B1 to State A (S129). The control means 21 of the electric vehicle 20 detects that the system state has transitioned from State B1 to State A by detecting a change in the control signal on the control line 29 (S130).

  Similarly, the wireless communication unit 12 of the power supply station 10 changes the control signal of State B1 held in its buffer 18 to the control signal of State A, and outputs the control signal of State A to the control line 17 The system state is changed from State B1 to State A (S131). The control means 11 of the power supply station 10 detects that the system state has transitioned from State B1 to State A by detecting a change in the control signal on the control line 17 (S132).

  As described above, in the non-contact charging system 100 according to this embodiment, the power supply station 10 and the electric vehicle 20 input / output control signals (wired signals) indicating the current system state on the control lines 17 and 29. In addition to the control means 11 and 21, the control signals output from the control means 11 and 21 onto the control lines 17 and 29 are converted into radio signals and transmitted, and the received radio signals are converted back into control signals. Thus, wireless communication means 12 and 22 for outputting on the control lines 17 and 29 are provided. Thereby, in non-contact charge, charge control equivalent to the CPLT function in contact charge can be performed.

  4A and 4B, the operations of the control units 11 and 21 of the power supply station 10 and the electric vehicle 20 are the same as those in the case where both of them are connected by a control line in conventional contact charging. Yes, the wireless communication means 12 and 22 are interposed between the control means 11 and 21, whereby a control signal (wired signal) exchanged between the control means 11 and 21 is converted into a wireless signal. Therefore, it is not necessary to change the hardware or software of the control means 11 and 21, and the control means 11 and 21 developed for contact charging can be used as they are to perform charging control for contactless charging.

  Each of the wireless communication means 12 and 22 of the power supply station 10 and the electric vehicle 20 includes buffers 18 and 30 that hold control signals obtained by inversely converting the received wireless signals. 30 is output to the control lines 17 and 29, so that even if a message loss or a reception error occurs temporarily due to deterioration of the radio wave environment or the like, the control signals are held in the buffers 18 and 30. Since the control signal can be continuously output on the control lines 17 and 29, each control means 11 and 21 can correctly detect the current system state.

Other embodiments.
In the above embodiment, the wireless communication means 12 and 22 of the power supply station 10 and the electric vehicle 20 measure the received signal strength (RSSI) when receiving a message, and if the RSSI is less than a predetermined threshold, the received message It may be determined that the reliability of the received message is low and the received message is discarded. At this time, the wireless communication units 12 and 22 continue to output the control signals already held in the buffers 18 and 30 on the control lines 17 and 29. Further, when message loss or reception error occurs continuously for a predetermined number of times due to remarkable deterioration of the radio wave environment, the wireless communication means 12 and 22 abnormally control signals held in their own buffers 18 and 30. It is also possible to change the system state to State E by changing to a control signal of State E, which means the occurrence of, and outputting it to the control lines 17 and 29.

  DESCRIPTION OF SYMBOLS 100 Non-contact charging system, 10 Power supply stand, 11 Control means, 12 Wireless communication means, 18 Buffer (holding means), 20 Electric vehicle (vehicle equipped with battery), 21 Control means, 22 Wireless communication means, 30 Buffer (holding means) .

Claims (6)

A non-contact charging system for charging a battery-equipped vehicle from a power supply stand,
Each of the power supply stand and the battery-equipped vehicle is
Control means for inputting and outputting wired signals for charge control;
A wireless communication unit that converts the wired signal output from the control unit into a wireless signal and transmits the wireless signal, and reversely converts the received wireless signal into the wired signal and outputs the signal to the control unit; Charging system.   The wireless communication means has holding means for holding the wired signal obtained by inversely converting the received wireless signal, and outputs the wired signal held in the holding means to the control means. The contactless charging system according to claim 1.   The wireless communication means measures the received signal strength of the received wireless signal, and when the received signal strength is less than a predetermined threshold, discards the received wireless signal and already holds it in the holding means. The non-contact charging system according to claim 2, wherein the wired signal is output to the control means.   The wireless communication means, when the received signal strength of the received wireless signal is less than the predetermined threshold continuously for a predetermined number of times, outputs the wired signal signifying occurrence of abnormality to the control means, The contactless charging system according to claim 3.   The contactless charging system according to claim 1, wherein the wired signal is a control signal defined in a CPLT function. A battery-equipped vehicle that performs contactless charging with a power supply stand,
Control means for inputting and outputting wired signals for charge control;
A battery-mounted device comprising: a wireless communication unit that converts the wired signal output from the control unit into a wireless signal and transmits the wireless signal, and reversely converts the received wireless signal into the wired signal and outputs the signal to the control unit. vehicle.

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