Charging system and vehicle and charge controller for the charging system

[0001] The present invention relates to a charging system for a battery installed in a vehicle and a vehicle and a charge controller for the charging system.

[0002] The present invention relates to a charging system for a battery installed in a vehicle.

[0003] A charging system for a vehicle battery is known which uses a commercial power supply available in a general house. A charging system is disclosed in Japanese Patent Application Publication No. 2008-61432, according to which an electronic control unit (ECU) is installed in a vehicle for controlling the vehicle battery charging. When charging a vehicle battery, a charging connector of the vehicle is connected to an outdoor outlet of a house through a charging cable. An identification (ID) box is installed in the house for authentication through communication with the ECU when charging the vehicle battery. If the authentication is established between the ID box and the ECU, charging is allowed. This helps to prevent vehicle theft effectively.

[0004] Another charging system disclosed in Japanese Patent Application Publication No 8-111909 has a charging device for charging a battery for an electric vehicle and a control unit controlling the charging device in accordance with the charge condition of the vehicle battery. The control unit has a charge time calculator determining the battery charge time based on the charge condition of the vehicle battery, a charge start time calculator determining the charge start time based on the battery charge completion time and the charge time, and a battery charge actuator for starting battery charging at the calculated charge start time.

[0005] According to the charging system disclosed in the above Publication No. 2008-61432, the charging cable is connected before the start of charging. Thus, battery charging cannot be started while the user of the vehicle is absent. In other words, the battery charging may not be performed at the user's desired time.

[0006] According to the charging system disclosed in the above Publication No. 8-111909, the above-described step of charging is performed by the control unit installed in the vehicle. If various settings for charging could be done in the house, user-friendliness may be improved. However, it is not preferable to add devices for communication between the house and the vehicle.

[0007] The present invention is directed to providing a charging system using a commercial power supply of a general house and making possible battery charging at any time desired by the user of the vehicle.

[0008] In accordance with the present invention, a charging system for charging a vehicle battery using a commercial power supply available in a construction on the ground includes a charge device, a power line, a time setting unit, and a control unit. The charge device mounted on a vehicle charges the vehicle battery. The power line connects between the construction on the ground and the vehicle. The time setting unit sets a charge start time for starting battery charging. The control unit is used for starting battery charging at the charge start time.

[0009] Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

[0018] FIG. 1 is an illustrative view showing a configuration of a charging system according to a preferred embodiment of the present invention. Referring to FIG. 1, there is shown a charging system 1 for charging a battery mounted on a vehicle 20 using a power supply available in a construction on the ground, such as house 1. The house 10 corresponds to a construction on the ground.

[0019] A charge controller 11 is provided in the house 10. The charge controller 11 has a clock 12, an input-output device (time setting unit as time setting means) 13, an ECU (control unit as control means or first control unit as first control means) 14, and a power line communication device (communication device as communication means) 15.

[0020] The clock 12 outputs real time digital data. The input-output device 13 has an input section for receiving input data from a user and an output section for providing output data that is necessary for battery charging. The input section is not limited to any specific device, but may be a touch panel device or an input device having buttons to input numbers and the like. The output section is provided by, for example, a display device. The user may set data of charge start conditions including a charge start time using the input-output device 13.

[0021] The ECU 14 receives real time digital data from the clock 12 and, if necessary, controls the charging operation in conjunction with a charge management controller 23 installed in the vehicle 20. The power line communication device 15 controls communication between the house 10 and the vehicle 20 through a power line 40. The power line communication device 15 is connected to an outlet 31 in the house 10.

[0022] A switchboard 30 having a plurality of terminals (T1, T2, . . . ) is provided in the house 10 for distributing electric power. to a plurality of outlets (31, 32 . . . ) of the house 10. The switchboard 30 is connected to a commercial power line network through a watt-hour meter 33.

[0023] The outlet 31 is disposed inside the house 10 and connected to the terminal T1 of the switchboard 30 The outlet 32 is disposed outside the house 10, and connected to the terminal T2 of the switchboard 30. The terminals T1, T2 are connected to each other within the switchboard 30, or may be connected to each other through a switch 34. It may be so arranged that the switch 34 selectively connects between the terminals of the switchboard 30 in accordance with the control of the ECU 14.

[0024] The vehicle 20 has a clock 21, an input-output device (time setting unit or as time setting means) 22, a charge management controller (control unit as control means or second control unit as second control means) 23, a power line communication device (communication device as communication means) 24, a main battery 25, and a charge and discharge device (charge device and discharge device) 26. The clock 21, the input-output device 22, and the power line communication device 24 in the vehicle 20 are substantially the same as counterparts 12, 13, 15 in the house 10, respectively.

[0025] The charge management controller 23 receives real time digital data from the clock 21 of the vehicle 20 and monitors the conditions of the main battery 25, such as an output voltage and a charge level. The charge management controller 23 controls the charging operation by itself, or in conjunction with the ECU 14 of the house 10.

[0026] The charge and discharge device 26 charges the main battery 25 using electric power supplied through the power line 40. In this case, the charge and discharge device 26 operates as an AC-DC converter. The charge and discharge device 26 may supply electric power charged in the main battery 25 to the house 10 through the power line 40. In this case, the charge and discharge device 26 operates as a DC-AC inverter. A switch 27 is disposed between the power line 40 and the charge and discharge device 26, and its operation is controlled by the charge management controller 23. The switch 27 may be incorporated in the charge and discharge device 26.

[0027] A power plug 41 is provided at the end of the power line 40. Before charging the main battery 25, or supplying electric power charged in the main battery 25 to the house 10, the power plug 41 is inserted into the outlet 32.

[0028] When charging the main battery 25 in the above-described charging system 1, the user inputs data of charge start conditions including the data of charge start time through the input-output device 13 or 22. Then, the ECU 14 and the charge management controller 23 transmit and receive control data through the power line communication devices 15, 24. When the charge start conditions are satisfied, the charge management controller 23 turns the switch 27 ON, thereby causing the charge and discharge device 26 to start charging the main battery 25. Power line communication using the power line communication devices 15, 24 is not limited to the use of a specific protocol, but may use any known protocol.

[0029] In the charging system 1 constructed as described above, the charging data including the data of the charge start conditions may be set either in the house 10, or in the vehicle 20. The following describes the structure and the operation in the case of setting the charging data in the house 10.

[0030] FIG. 2 is an illustrative view showing the configuration of charging system in the case of setting charging data in the house 10 In this configuration of the charging system, the vehicle 20 needs no input-output device 22, and the rest of the configuration of the charging system is substantially the same as that described above with reference to FIG. 1.

[0031] FIG. 3 is a sequence diagram showing the steps of operation in the charging system according to the preferred embodiment of the present invention in the case of setting charging data in the house 10. In FIG. 3, it is supposed that the vehicle 20 is ready for charging, or the charge management controller 23 and the power line communication device 24 are ready for operation, and also the power plug 41 of the power line 40 is inserted into the outlet 32.

[0032] The user inputs data of the charging operation through the input-output device 13 which is provided in the charge controller 11. The data of the charging operation according to the preferred embodiment of the present invention includes:

(1) charge start time, and

(2) condition for charge completion.

[0033] The condition for charge completion may be, for example, a charge level of the main battery 25, such as full charge or 90 percent charge. Thus, the main battery 25 may be charged to any desired level. The condition for charge completion may be the charge completion time. In this case, the condition may be set such that the charging is performed in the midnight when the electric rate is relatively low.

[0034] Subsequently, the step of transmitting the setting data is performed as follows. When the ECU 14 of the charge controller 11 transmits an enquiry signal (ENQ) to the charge management controller 23 of the vehicle 20, the charge management controller 23 returns an acknowledgement signal (ACK), accordingly. The ECU 14 receiving the ACK transmits charge control data. Referring to FIG. 4, the charge control data includes a charge/discharge flag, charge start condition, selection of charge completion condition, and charge completion condition. The charge/discharge flag identifies which of the charging or discharging operation is selected. The following description will be made in the case when the charging operation is selected. The charge start condition specifies the start time for charging. The selection of condition for charge completion determines which of the charge level and the charge completion time is selected as the condition for charge completion.

[0035] The charge management controller 23 stores the received charge control data in its memory and returns an acknowledgement signal (ACK). The ECU 14 of the house 10 receiving the ACK transmits an end of transmission signal (EOT). This completes the step of transmitting the setting data.

[0036] After completing the above-described step of transmitting the setting data, the charge management controller 23 monitors the clock 21 of the vehicle 20. When the charge start time specified by the start condition is reached, the step of confirming the connection is performed as follows before starting the charging operation. That is, the charge management controller 23 transmits an enquiry signal (ENQ), and the ECU 14 returns an acknowledgement signal (ACK). The charge management controller 23 receiving the ACK starts the charging operation. Specifically, the charge management controller 23 turns on the switch 27, thereby starting the charge and discharge device 26.

[0037] During the charging operation, the charge management controller 23 constantly monitors whether or not the condition for charge completion is fulfilled. If the full charge is specified as the condition of charge completion, the charge management controller 23 monitors the output voltage of the main battery 25 and stops the battery charging when the output voltage is increased to a level corresponding to the condition of full charge. This is accomplished by turning OFF the switch 27 thereby to stop the charge and discharge device 26.

[0038] During the charging operation, the step of confirming the connection is performed as follows. The charge management controller 23 transmits an enquiry signal (ENQ), and the ECU 14 returns in response thereto an acknowledgement signal (ACK). Then, the charge management controller 23 periodically transmits charge-on data indicating that the charge and discharge device 26 is charging the main battery 25. Then, the ECU 14 returns an acknowledgement signal (ACK) every time when the charge-on data is received. By this step of confirming the connection, the charge management controller 23 can confirm whether or not the connection between the house 10 and the vehicle 20 is established correctly. If the power plug 41 of the power line 40 is removed from the outlet 32, or the power line 40 is disconnected, the charge management controller 23 fails to receive the ACK, thereby detecting a connection error. When the connection error is detected, the charge management controller 23 may output an alarm signal.

[0039] According to the charging system 1 of the preferred embodiment, the communication between the ECU 14 and the charge management controller 23 is performed through the power line 40 which transmits electric power for charging. Thus, if an error occurs in transmission of electric power through the power line 40, the charge management controller 23 can detect the error instantly and directly. The ECU 14 and/or the charge management controller 23 may store logs of the step of confirming the connection during the charging operation.

[0040] When the charging is completed, the charge management controller 23 transmits an enquiry signal (ENQ), and the ECU 14 returns an acknowledgement signal (ACK). Then, the charge management controller 23 transmits charge completion data indicative of the completion of charging. The ECU 14 receives the charge completion data, and returns an acknowledgement signal (ACK). The charge management controller 23 receiving the ACK transmits an end of transmission signal (EOT) This completes a series of steps of the charging operation.

[0041] According to the procedure shown by the sequence diagram in FIG. 3, the charge management controller 23 installed in the vehicle 20 monitors a charge start time, but the present invention is not limited to the step. It may be so arranged that, after the charge start time is input into the charge controller 11 of the house 10, the charge controller 11 monitors to determine whether or not the real time reaches the charge start time and transmits a signal to the vehicle 20 to start charging when the charge start time is reached.

[0042] The discharging step for supplying electric power from the main battery 25 to the house 10 is substantially the same as the step shown by the sequence diagram in FIG. 3. In the discharging step, the charge management controller 23 makes the charge and discharge device 26 to operate as DC-AC inverter. The charge controller 11 controls the operation of the switch 34 to change connections of the switchboard 30 so as to transmit electric power generated by the main battery 25 to the desired devices such as electric equipment and a battery in the house 10.

[0043] FIG. 5 is an illustrative view showing the configuration of the charging system in the case of setting charging data at the vehicle 20. In this case, the house 10 may dispense with the charge controller 11, and the vehicle 20 may dispense with the power line communication device 24. The rest of the configuration of the charging system in FIG. 5 is substantially the same as that described above with reference to FIG. 1.

[0044] FIG. 6 is a sequence diagram showing the steps of operation in the case of setting charging data in the vehicle 20 The operation of the charge management controller 23 is basically the same as that in the case of setting charging data in the house 10. The charge management controller 23 does not necessarily need to communicate with the ECU 14. In the case of setting charging data in the vehicle 20, the ECU 14 and the power line communication device 15 are installed in the house 10, and the power line communication device 24 is mounted on the vehicle 20. The step of confirming the connection may be performed during the charging operation.

[0045] According to the above-described preferred embodiment, data is transmitted between the house 10 and the vehicle 20 by power line communication, but the present invention is not limited to this structure. Alternatively, data may be transmitted by wireless as shown in FIG. 7. In this configuration, the charge controller 11 has a wireless communication device 51 instead of the power line communication device 15, and the vehicle 20 has a wireless communication device 52 instead of the power line communication device 24. Therefore, radio signals are transmitted between the wireless communication devices 51, 52 The wireless communication protocol is not limited, but it may use, for example, IEEE 802.11 standard or Worldwide Interoperability for Microwave Access (WiMax).

[0046] The start time does not necessarily be set for the charging or discharging, but the charging or discharging may be started immediately.