BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The invention relates to a power supply device, a vehicle, and a charging system. More specifically, the invention relates to a technology for preventing electric power stealing in a charging system for a vehicle, in which electric power is supplied to the vehicle using an external power source.

2. Description of the Related Art

[0002] Recently, attention has been focused on electrically-driven vehicles, as environmentally-friendly vehicles. The electrically-driven vehicles are provided with power storage devices (for example, a secondary battery and a capacitor), and the electrically-driven vehicles travel using driving power generated from electric . power stored in the power storage devices. The electrically-driven vehicles include, for example, an electric vehicle, a hybrid vehicle, and a fuel cell vehicle. Thus, a technology, in which the power storage device provided in the electrically-driven vehicle is charged using a commercial power source with high power generation efficiency, has been proposed.

[0003] The hybrid vehicle, in which an in- vehicle power storage device is charged with electric power from a power source outside the vehicle (hereinafter, simply referred to as "external power source") as in the electric vehicle, is known. For example, "the plug-in hybrid vehicle" is known. The power storage device in the plug-in hybrid vehicle is charged with electric power from a power source in an ordinary house by connecting the outlet of the power source provided in the house to a charging port provided in the vehicle using a charging cable. Thus, it is expected that fuel efficiency of the hybrid vehicle will be increased. [0004] Japanese Patent Application Publication No. 2008-061432 (JP-A-2008-061432) describes a charging system in which a vehicle is connected to a power source in a house using a power line, and a power storage device provided in the vehicle is charged. In the charging system, authentication is performed between an ID box (authentication management device) installed in the house and the vehicle through power line communication. The supply of electric power to the power storage device is permitted on the condition that the vehicle is authenticated.

[0005] In the technology described in the publication No. 2008-061432, if the vehicle to be supplied with electric power is not compatible with the authentication management device in the house, electric power cannot be supplied to the vehicle. This discourages a thief from stealing the vehicle that needs to be supplied with electric power. Thus, it is possible to increase the anti-theft property of the vehicle.

[0006] Even when the vehicle is authenticated in the charging system in which authentication is performed between the vehicle to be supplied with electric power and the authentication management device, for example, if a power source path from a power output end (for example, an outlet) in the house to the vehicle is divided using dividing means or the like, it becomes possible to supply electric power to a vehicle that is different from the authenticated vehicle. Thus, there is a possibility that electric power is stolen.

[0007] Also, if electric leakage occurs in the power source path or a power line inside the vehicle, electric power may be lost during a period in which electric power is supplied to the vehicle.

SUMMARY OF THE INVENTION

[0008] The invention prevents electric power stealing in a charging system for a vehicle, in which the vehicle is supplied with electric power from a power source outside the vehicle.

[0009] A first aspect of the invention relates to a power supply device that supplies electric power from an external power source to a vehicle. The power supply device includes a control device that determines whether to permit supply of electric power to the vehicle, based on a difference between a value of electric power supplied to the vehicle and a value of received electric power, the value of the received electric power being included in a signal received from the vehicle through communication.

[0010] The power supply device may further include a switch that allows and interrupts supply of electric power from the external power source to the vehicle. If supply of electric power from the power supply device is permitted, the control device may electrically connect the power supply device to the external power source using the switch, and if the supply of electric power from the power supply device is prohibited, the control device may electrically disconnect the power supply device from the external power source using the switch.

[0011] If an absolute value of the difference is larger than a predetermined threshold value, the control device may prohibit the supply of electric power to the vehicle, and if the absolute value of the difference is equal to or smaller than the predetermined threshold value, the control device may permit the supply of electric power to the vehicle.

[0012] The signal may be communicated between the vehicle and the power supply device through wired communication. Electric power may be supplied to the vehicle using a charging cable. The charging cable may include a communication line used to perform communication. The signal may be communicated between the vehicle and the power supply device using the communication line.

[0013] Electric power may be supplied to the vehicle using a charging cable. The charging cable may include a power line used to transmit electric power. The signal may be communicated between the vehicle and the power supply device through power line communication using the power line.

[0014] The signal may be communicated between the vehicle and the power supply device through wireless communication.

[0015] The power supply device may further include an operating portion through which information regarding a charging fee is input. The control device may set an amount of electric energy that is allowed to be supplied to the vehicle according to the information regarding the charging fee input through the operating portion. If supply of the set amount of electric energy has been completed, the control device may prohibit the supply of electric power to the vehicle, regardless of the difference.

[0016] The vehicle may include an operating portion through which information regarding a charging fee is input, and a control portion confiugred to set an amount of electric energy that is allowed to be supplied from the power supply device according to the information regarding the charging fee. If supply of the amount of electric energy, which is set by the control portion, has been completed, the control device may prohibit the supply of electric power to the vehicle, regardless of the difference.

[0017] A second aspect of the invention relates to a charging system including the vehicle; and the power supply device according to the above-described aspect.

[0018] A third aspect of the invention relates to a vehicle including a power storage device, a charging device, and a control device. The power storage device is charged with electric power supplied from a power supply device outside the vehicle. The charging device charges the power storage device with electric power received from the power supply device. The control device determines whether to permit supply of electric power from the power supply device, based on a difference between a value of electric power received from the power supply device and a value of supplied electric power, the value of the supplied electric power being included in a signal received from the power supply device through communication.

[0019] If an absolute value of the difference is larger than a predetermined threshold value, the control device may prohibit the supply of electric power from the power supply device, and if the absolute value of the difference is equal to or smaller than the predetermined threshold value, the control device may permit the supply of electric power from the power supply device.

[0020] The power supply device may include a switch that allows and interrupts supply of electric power from the external power source to the vehicle. If supply of electric power from the power supply device is permitted, the switch may electrically connect the power supply device to the external power source, and if the supply of electric power from the power supply device is prohibited, the switch may electrically disconnect the power supply device from the external power source.

[0021] The vehicle may further include an operating portion through which information regarding a charging fee is input. The control device may set an amount of electric energy that is allowed to be supplied from the power supply device according to the information regarding the charging fee input through the operating portion. If supply of the set amount of electric energy has been completed, the control device may prohibit the supply of electric power from the power supply device, regardless of the difference.

[0022] The power supply device may include an operating portion through which information regarding a charging fee is input, and a control portion confiugred to set an amount of electric energy that is allowed to be supplied from the power supply device according to the information regarding the charging fee input through the operating portion. If supply of the amount of electric energy, which is set by the control portion, has been completed, the control device may prohibit the supply of electric power from the power supply device, regardless of the difference.

[0023] A fourth aspect of the invention relates to a charging system including the power supply device; and the vehicle according to the above-described aspect.

[0024] According to the above-described aspects, it is possible to prevent electric power stealing in the charging system in which the vehicle is supplied with electric power from the external power source outside the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The foregoing and further objects, features and advantages of the invention will become apparent from the following description of example embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein:

FIG. 1 is a schematic diagram showing a charging system according to an embodiment of the invention;

FIG. 2 is a block diagram showing the entire charging system shown in FIG. 1;

FIG. 3 is a diagram used to explain an example in which electric power stealing is occurring in the charging system;

FIG. 4 is a diagram used to explain the outline of a power supply determination control in the embodiment of the invention;

FIG 5 is a functional block diagram used to explain the power supply determination control executed by a vehicle ECU and an electric power transmission ECU in a first embodiment of the invention;

FIG 6 is a flowchart used to explain in detail the power supply determination control executed by the electric power transmission ECU in the first embodiment;

FIG 7 is a block diagram showing the entire charging system in the case where wireless communication is employed as communication means;

FIG. 8 is a block diagram showing the entire charging system in the case where power line communication using a power line included in a charging cable is employed as the communication means;

FIG 9 is a block diagram showing the entire charging system in the case where an operating portion is provided in a vehicle;

FIG 10 is a functional block diagram used to explain the power supply determination control executed by the vehicle ECU and the electric power transmission ECU in the case where the operating portion is provided in the vehicle;

FIG 11 is a functional block diagram used to explain the power supply determination control executed by the vehicle ECU and the electric power transmission ECU in the charging system according to a second embodiment of the invention;

FIG. 12 is a flowchart used to explain in detail the power supply determination control executed by the vehicle ECU in the second embodiment of the invention; and

FIG. 13 is a functional block diagram used to explain the power supply determination control executed by the vehicle ECU and the electric power transmission ECU in the charging system according to a modified example of the second embodiment. DETAILED DESCRIPTION OF EMBODIMENTS

[0026] Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. In the drawings, the same and corresponding portions are denoted by the same reference numerals, and the description thereof will not be repeated.

First embodiment

[0027] As shown in FIG. 1, the charging system 10 includes a vehicle 100, a power supply device 300, and a charging cable 400.

[0028] The power supply device 300 supplies electric power from an external power source 500 to the vehicle 100 through the charging cable 400. An example of the external power source 500 is a commercial power source. The vehicle 100 receives alternating-current (AC) power from the power supply device 300. In the vehicle 100, the received AC power is converted to direct-current (DC) power with which a power storage device 110 can be charged. The received AC power is converted to the DC power using a charging device 200. Thus, the power storage device 110 is charged with the DC power.

[0029] FIG. 2 is a block diagram showing the entire charging system 10 shown in FIG. 1, which includes the vehicle 100, the power supply device 300, and the charging cable 400.

[0030] The vehicle 100 includes the power storage device 110, a System Main Relay SMRl, a Power Control Unit (PCU) 120 that is a drive device, a motor-generator 130, a power transmission gear 140, drive wheels 150, and a vehicle Electronic Control Unit (ECU) 160.

[0031] The power storage device 110 is an electric power storage element that is configured so that the electric power storage element is charged with electric power, and electric power is discharged from the electric power storage element. For example, the power storage device 110 is configured to include a secondary battery such as a lithium ion battery, a nickel hydride battery, or a lead battery, and/or a power storage element such as an electrical double layer capacitor.

[0032] The power storage device 110 is connected to the PCU 120 that drives the motor-generator 130 through the system main relay SMRl. The power storage device 110 supplies electric power to the PCU 120 to generate drive power for the vehicle 100. In the power storage device 110, electric power generated by the motor-generator 130 is stored. The output of the power storage device 110 is^ for example, 200 V.

[0033] In the power storage device 110, the value of a voltage VB of the power storage device 110 and the value of an electric current IB of the power storage device 110 are detected by sensors (not shown), and the detected value of the voltage VB and the detected value of the electric current IB are output to the vehicle ECU 160.

[0034] Relays included in the system main relay SMRl are inserted in a power line PL1 and an earth conductor NL1, respectively. The power line PL1 and the earth conductor NL1 connect the power storage device 110 to the PCU 120. The system main relay SMRl allows and interrupts the supply of electric power between the power storage device 110 and the PCU 120, based on a control signal SEl transmitted from the vehicle ECU 160.

[0035] The PCU 120 is configured to include electric power conversion devices such as a converter and an inverter, although the electric power conversion devices are not shown in the drawing. The converter and the inverter are controlled by control signals PWC and PWI, respectively. The control signals PWC and PWI are transmitted from the vehicle ECU 160. Thus, the DC power supplied from the power storage device 110 is converted to the AC power used to drive the motor-generator 130.

[0036] The motor-generator 130 is an AC rotating electrical machine. For example, the motor-generator 130 is a permanent magnet type synchronous motor that includes a rotor in which a permanent magnet is embedded.

[0037] Torque output from the motor-generator 130 is transmitted to the drive wheels 150 via the power transmission gear 140 constituted by a speed reducer and/or a power split mechanism. Thus, the vehicle 100 travels. When regenerative braking is performed in the vehicle 100, the motor-generator 130 generates electric power using the a

rotational force of the drive wheels 150. The PCU 120 converts the generated electric power to the electric power for charging, with which the power storage device 110 can be charged.

[0038] In a hybrid vehicle in which an engine (not shown) is provided in addition to the motor-generator 130, necessary vehicle driving power is generated by operating the engine and the motor-generator 130 in a coordinated manner. In this case, the power storage device 110 may be charged with electric power generated using the rotation of the engine.

[0039] That is, the vehicle 100 in the embodiment represents a vehicle provided with a motor that generates vehicle driving power. Thus, examples of the vehicle 100 include the hybrid vehicle in which the vehicle driving power is generated using the engine and the motor, and an electric vehicle and a fuel cell vehicle in which the engine is not provided. In FIG 2, the vehicle 100 is configured to include one motor-generator 130. However, the vehicle 100 may be configured to include a plurality of motor-generators 130. .

[0040] The vehicle ECU 160 includes a Central Processing Unit (CPU), a memory device, and an input/output buffer, although none of them are shown in FIG. 2. Signals from the sensors and the like are input to the vehicle ECU 160, and the vehicle ECU 160 outputs control signals to devices. In addition, the vehicle ECU 160 executes controls for the vehicle 100 and the devices. The controls are not limited to controls executed by software. The vehicle ECU 160 may be configured using hardware (an electronic circuit) for exclusive use, to perform the controls.

[0041] The vehicle ECU 160 outputs the control signals to control the PCU 120, the system main relay SMR1, and the like. Also, the vehicle ECU 160 receives, from the power storage device 110, the value of the voltage VB and the value of the electric current IB of the power storage device 110. The vehicle ECU 160 computes the State of Charge (SOC) of the power storage device 110 based on the received information.

[0042] The vehicle 100 further includes a communication portion 170, the charging device 200, a voltage sensor 210, an electric current sensor 220, an inlet 230, and a relay RYl so that the power storage device 110 is charged with the electric power supplied from the power supply device 300.

[0043] A charging connector 410 in the charging cable 400 is connected to the inlet 230. Thus, the electric power supplied from the power supply device 300 is transmitted to the vehicle 100 through the charging cable 400.

[0044] Relays included in the relay RYl are inserted in a power line PL2 and an earth conductor NL2, respectively. The power line PL2 and the earth conductor NL2 connect the power storage device 110 to the charging device 200. The relay RYl allows and interrupts the supply of electric power between the power storage device 110 and the charging device 200, based on a control signal SE2 transmitted from the vehicle ECU 160.

[0045] The charging device 200 is connected to the inlet 230 through power lines ACL1 and ACL2. The charging device 200 is connected to the power storage device 110 through the power line PL2 and the earth conductor NL2. The charging device 200 is controlled by a control signal PWD transmitted from the vehicle ECU 160. The charging device 200 converts the AC power supplied from the power supply device 300 to the DC power with which the power storage device 110 can be charged.

[0046] The voltage sensor 210 is provided between the power lines ACL1 and ACL2 and connected to the power lines ACL1 and ACL2. The voltage sensor 210 detects the value of an AC voltage VR supplied to the power lines ACL1 and ACL2, and outputs the detected value of the AC voltage VR to the vehicle ECU 160. The electric current sensor 220 detects the value of an electric current IR that flows through the power line ACL1, and outputs the detected value of the electric current IR to the vehicle ECU 160. The electric current sensor 220 may detect the value of an electric current that flows through the power line ACL2.

[0047] The vehicle ECU 160 computes the value of received electric power that is electric power received from the power supply device 300, based on the received information, that is, the value of the voltage VR detected and output from the voltage sensor 210 and the value of the electric current IR detected and output from the electric current sensor 220. Instead of providing the voltage sensor 210 and the electric current sensor 220, an electric power sensor may be connected to the power lines ACL1 and ACL2 so that the electric power sensor directly detects the value of the received electric power and outputs the detected value of the received electric power to the vehicle ECU 160.

[0048] The communication portion 170 is a communication interface between the vehicle ECU 160 and an electric power transmission ECU 350 in the power supply device 300. The communication portion 170 is configured to transmit and receive signals to and from a communication portion 320 included in the power supply device 300 through wired communication, that is, through a communication line 440 included in the charging cable 400. In FIG 2, the communication portion 170 is shown as an element separate from the vehicle ECU 160. However, the configuration may be such that the vehicle ECU 160 includes the function of the communication portion 170.

[0049] The charging cable 400 includes the charging connector 410, a plug 420, a power line 430, and the communication line 440.

[0050] The charging connector 410 can be connected to the inlet 230 of the vehicle 100. The plug 420 can be connected to a connection portion 360 that is an electric power output end of the power supply device 300.

[0051] The power line 430 is connected to power lines ACL10 and ACL20 in the power supply device 300 through the plug 420, and connected to the power lines ACL1 and ACL2 in the vehicle 100 through the charging connector 410. Thus, the electric power supplied from the power supply device 300 is transmitted to the vehicle 100 through the power line 430.

[0052] The communication line 440 is connected to the power supply device 300 through the plug 420, and connected to the vehicle 100 through the charging connector 410. Signals are transmitted between the communication portion 170 in the vehicle 100 and the communication portion 320 in the power supply device 300 through the communication line 440.

[0053] A relay (not shown) that interrupts electric power when electric leakage or the like is detected may be inserted in the power line 430 in the charging cable 400.

[0054] The power supply device 300 includes an operating portion 310, the communication portion 320, a voltage sensor 330, an electric current sensor 340, the electric power transmission ECU 350, the connection portion 360, and a relay RY10.

[0055] Relays included in the relay RY10 are inserted in the power lines ACL10 and ACL20, _. respectively. The power lines ACL10 and ACL20 connect the external power source 500 to the connection portion 360. The relay RYIO allows and interrupts the supply of electric power from the external power source 500 to the charging cable 400 based on a control signal SE10 transmitted from the electric power transmission ECU 350.

[0056] The voltage sensor 330 is connected to the power lines ACL10 and ACL20. The voltage sensor 330 detects the value of an AC voltage VS supplied from the external power source 500, and outputs the detected value of the AC voltage VS to the electric power transmission ECU 350. The electric current sensor 340 is detects the value of an electric current IS that flows through the power line ACL10, and outputs the detected value of the electric current IS to the electric power transmission ECU 350. The electric current sensor 340 may detect the value of an electric current that flows through the power line ACL20.

[0057] The electric power transmission ECU 350 computes the value of supplied electric power that is electric power transmitted to the vehicle 100, based on the received information, that is, the value of the voltage VS detected and transmitted from the voltage sensor 330 and the value of the electric current IS detected and transmitted from the electric current sensor 340. Instead of providing the voltage sensor 330 and the electric current sensor 340, an electric power sensor may be connected to the power lines ACL10 and ACL20 so that the electric power sensor directly detects the value of the supplied electric power, and outputs the detected value of the supplied electric power to the electric power transmission ECU 350.

[0058] The communication portion 320 is a communication interface between the electric power transmission ECU 350 and the vehicle ECU 160 in the vehicle 100. The communication portion 320 is configured to transmit and receive signals to and from the communication portion 170 in the vehicle 100 through wired communication, that is, through the communication line 440 included in the charging cable 400. The configuration may be such that the electric power transmission ECU 350 includes the function of the communication portion 320.

[0059] The operating portion 310 is an operating interface through which a charging operator inputs a fee for charging (hereinafter, referred to as "charging fee") and the like , when the charging operator performs an operation for charging, and which displays an unused portion of the charging fee and a charged state. The operating portion 310 is configured to include a switch for operation, a display unit, and a card reader that reads a prepaid card, a credit card, and the like, although none of them are shown in the drawing. The operating portion 310 outputs information INP regarding the charging fee input by the operator, to the electric power transmission ECU 350.

[0060] The electric power transmission ECU 350 includes a CPU, a memory device, and an input/output buffer, although none of them are shown in FIG 2. Signals from the sensors and the like are input to the electric power transmission ECU 350, and the electric power transmission ECU. 350 outputs control signals to the devices. In addition, the electric power transmission ECU 350 executes controls for the power supply device 300. The controls are not limited to controls executed by software. The electric power transmission ECU 350 may be configured using hardware (an electronic circuit) for exclusive use, to perform the controls.

[0061] The electric power transmission ECU 350 receives the information INP regarding the charging fee input through the operating portion 310. Then, the power transmission 350 determines whether there is an unused portion of the charging fee, based on the value of the electric power supplied to the vehicle 100. In other words, the electric power transmission ECU 350 sets the amount of electric energy that is allowed to be supplied to the vehicle 100, according to the information INP regarding the charging fee input through the operating portion 310, and determines whether the supply of the set amount of electric energy has been completed. Also, the electric power transmission ECU 350 determines whether to permit charging, based on the result of the determination as to whether there is an unused portion of the charging fee and the result of a determination in a power supply determination control described later. The electric power transmission ECU 350 controls the relay RY10, and outputs a charging start command to the vehicle 100, according to the result of the determination as to whether to permit charging. Further, if charging is prohibited by the power supply determination control, the electric power transmission ECU 350 outputs an alarm signal ALM to the operating portion 310 to provide a visual or audible warning to the operator.

[0062] In the charging system, authentication may be performed between a vehicle and the power supply device so that electric power is not supplied from the power supply device to a vehicle other than a target vehicle to which electric power should be supplied from the power supply device.

[0063] However, even in the case where the authentication is performed between a vehicle and the power supply device, for example, if the connection portion 360 (e.g., an outlet) that is the output end of the power supply device 300 is modified and another connection portion 360A is connected in parallel to the connection portion 360 as shown in FIG 3, there is a possibility that electric power is supplied to a vehicle 100A that is not the target vehicle, and that is connected to the power supply device 300 through a charging cable 400A when electric power is supplied to the vehicle 100 that is the target vehicle. As a result, a driver of the vehicle 100 may pay the cost of electric power supplied to the vehicle 100A, that is, electric power stealing may occur.

[0064] Even in the case where electric power stealing is not occurring, for example, if electric leakage is occurring in a power supply path from the power supply device 300 to the power storage device 110 in the vehicle 100, there is a possibility that the driver of the vehicle 100 pays the cost of electric power lost due to the electric leakage.

[0065] Thus, in the embodiment, the power supply determination control is executed to determine whether no electric power stealing is occurring and no electric leakage is occurring, that is, whether electric power can be appropriately supplied to the vehicle, by comparing the value of the electric power supplied from the power supply device 300 and the value of the electric power received by the vehicle 100. Thus, it is possible to prevent electric power stealing when the vehicle is supplied with electric power from outside. In addition, it is possible to detect electric leakage in the power supply path.

[0066] FIG 4 is a diagram used to explain the outline of the power supply determination control according to the embodiment. The upper portion of FIG. 4 shows examples of the supplied electric power and the received electric power in the case where the vehicle is normally supplied with electric power from outside. The lower portion of FIG. 4 shows examples of the supplied electric power and the received electric power in an abnormal situation where electric power stealing or electric leakage is occurring.

[0067] As shown in FIG. 4, even in the case where the vehicle is normally supplied with electric power from outside, there is a possibility that the electric power received by the vehicle becomes lower than the electric power supplied from the power supply device to some degree due to loss in the power supply path, or the like. Therefore, if a difference between the value of the supplied electric power and the value of the received electric power is equal to or smaller than a threshold value a set in advance taken into account the loss or the like (refer to a difference ΔΡ1 in FIG. 4), it is possible to determine that no electric power stealing is occurring and no electric leakage is occurring, and thus, the vehicle can be normally supplied with electric power from outside.

[0068] In contrast, if the difference between the value of the supplied electric power and the value of the received electric power is larger than the threshold value a (refer to a difference ΔΡ2 in FIG 4), it is possible to determine that there is a possibility that electric power stealing or electric leakage is occurring in the power supply path.

[0069] FIG 5 is a functional block diagram used to explain the power supply determination control executed by the vehicle ECU 160 and the electric power transmission ECU 350. Each functional block in FIG 5 and functional block diagrams in FIG. 10, FIG 11, and FIG. 13 described later is implemented when the vehicle ECU 160 or the electric power transmission ECU 350 executes a process in a hardware or software manner.

[0070] First, the functional blocks of the electric power transmission ECU 350 in the power supply device 300 will be described. As shown in FIG. 2 and FIG. 5, the electric power transmission ECU 350 includes a charging fee determination portion 351, an electric power computation portion 352, a power supply determination portion 353, and a relay control portion 354.

[0071] The electric power computation portion 352 receives the detected value of the voltage VS and the detected value of the electric current IS from the voltage sensor 330 and the electric current sensor 340, respectively. The electric power computation portion 352 computes the value of supplied electric power PS based on the received information. Then, the electric power computation portion 352 outputs the computed value of the supplied electric power PS to the charging fee determination portion 351 and the power supply determination portion 353.

[0072] The charging fee determination portion 351 receives, from the operating portion 310, the information INP regarding the charging fee input by the operator. Then, the charging fee determination portion 351 calculates an electric power cost (i.e., the cost of used electric power) corresponding to the value of the supplied electric power PS received from the electric power computation portion 352, and computes an unused portion of the charging fee based on the information INP regarding the charging fee input by the operator and the electric power cost. Then, the charging fee determination portion 351 determines whether there is an unused portion of the charging fee, and outputs a determination flag FLG to the power supply determination portion 353. More specifically, if there is an unused portion of the charging fee, the charging fee determination portion 351 sets the determination flag FLG to ON. If there is no unused portion of the charging fee, the charging fee determination portion 351 sets the determination flag FLG to OFF. In other words, the charging fee determination portion 351 sets the amount of electric energy that is allowed to be supplied to the vehicle 100, according to the information INP regarding the charging fee input through the operating portion 310, and determines whether the supply of the set amount of electric energy has been completed.

[0073] The power supply determination portion 353 receives the determination flag FLG from the charging fee determination portion 351, and receives the value of the supplied electric power PS from the electric power computation portion 352. Also, the power supply determination portion 353 further receives the value of the received electric power PR that has been computed by the vehicle ECU 160, and received by the communication portion 320. Then, the power supply determination portion 353 determines whether to permit the supply of electric power to the vehicle 100, based on the received information.

[0074] More specifically, if the determination flag FLG is OFF (that is, if the there is no unused portion of the charging fee), the power supply determination portion 353 prohibits the supply of electric power. If the determination flag FLG is ON (that is, if there is an unused portion of the charging fee), the power supply determination portion 353 determines whether electric power stealing or electric leakage is occurring by determining whether the difference between the value of the supplied electric power PS and the value of the received electric power PR is larger than the predetermined threshold value a. If the difference between the value of the supplied electric power PS and the value of the received electric power PR is equal to or smaller than the predetermined threshold value a, the power supply determination portion 353 permits the supply of electric power to the vehicle 100. If the difference between the value of the supplied electric power PS and the value of the received electric power PR is larger than the predetermined threshold value a, the power supply determination portion 353 prohibits the supply of electric power to the vehicle 100. The power supply determination portion 353 generates a power supply signal CHG based on the result of the determination. Then, the power supply determination portion 353 outputs the generated power supply signal CHG to the relay control portion 354, and transmits the generated power supply signal CHG to the vehicle ECU 160 through the communication portion 320.

[0075] If the supply of electric power is prohibited based on the result of the above-described determination, the power supply determination portion 353 outputs the alarm signal ALM to the operating portion 310 to notify the operator that the supply of electric power is prohibited. In response to the alarm signal ALM, the operating portion 310 outputs a visual warning using a lamp or the display unit, or outputs an audible warning using a buzzer or a chime.

[0076] The relay control portion 354 receives the power supply signal CHG from the power supply determination portion 353. Then, the relay control portion 354 sets the control signal SE10 for the relay RY10 in accordance with the power supply signal CHG, thereby controlling the relay RY10. More specifically, if the supply of electric power is permitted, the relay control portion 354 closes the relay RY10 to allow the supply of electric power. If the supply of electric power is prohibited, the relay control portion 354 opens the relay RY10 to interrupt the supply of electric power.

[0077] Next, the functional blocks of the vehicle ECU 160 in the vehicle 100 will be described. The vehicle ECU 160 includes an electric power computation portion 161 and a charging control portion 162.

[0078] The electric power computation portion 161 receives the detected value of the voltage VR and the detected value of the electric current IR from the voltage sensor 210 and the electric current sensor 220, respectively. The electric power computation portion 161 computes the value of the received electric power PR based on the received information. Then, the electric power computation portion 161 transmits the computed value of the received electric power PR to the electric power transmission ECU 350 through the communication portion 170.

[0079] The charging control portion 162 receives the power supply signal CHG from the electric power transmission ECU 350 through the communication portion 170. Then, the charging control portion 162 generates the control signal PWD and the control signal SE2 based on the power supply signal CHG, thereby controlling the charging device 200 and the relay RY10. Thus, the power storage device 110 is .charged.

[0080] When the electric power computation portions 352 and 161 compute the value of the supplied electric power PS and the value of the received electric power PR, respectively, it is necessary to detect the value of the voltage and the value of the electric current. Therefore, the power supply device 300 needs to actually supply electric power to the vehicle 100. Accordingly, although not shown in FIG 5, the relays RY1 and RY10 and the charging device 200 are controlled so that electric power is supplied for testing for a short time period, before the power supply determination portion 353 determines whether to permit the supply of electric power.

[0081] FIG. 6 is a flowchart used to explain in detail the power supply determination control executed by the electric power transmission ECU 350. Each step in the flowchart in FIG. 6 is implemented when a program stored in advance in the electric power transmission ECU 350 is invoked by a main program and executed at predetermined time intervals or when a predetermined condition is satisfied. Alternatively, some steps may be implemented by hardware (an electronic circuit) for exclusive use.

[0082] As shown in FIG. 6, when the electric power transmission ECU 350 recognizes that the charging cable 400 is connected to the vehicle 100 and the power supply device 300, the electric power transmission ECU 350 determines whether there is an unused portion of the charging fee input by the operator in step (hereinafter, , abbreviated to S) 100.

[0083] If there is an unused portion of the charging fee (YES in S100), the control proceeds to S110. In S110, the electric power transmission ECU 350 executes the control to supply electric power for testing as described above, and computes the value of the supplied electric power PS based on the values detected by the voltage sensor 330 and the electric current sensor 340. Then, in S120, the electric power transmission ECU 350 acquires the value of the received electric power PR from the vehicle ECU 160 through the communication portion 320.

[0084] Then, in S130, the electric power transmission ECU 350 determines whether the absolute value of the difference between the value of the supplied electric power PS and the value of the received electric power PR is larger than the predetermined threshold value a. [0085] If the absolute value of the difference between the value of the supplied electric power PS and the value of the received electric power PR is equal to or smaller than the predetermined threshold value a (NO in S130), the electric power transmission ECU 350 determines that no electric power stealing is occurring and no electric leakage is occurring. Then, the control proceeds to S140. In S140, the electric power transmission ECU 350 permits the supply of electric power and sets the power supply signal CHG to ON.

[0086] Then, in S150, the electric power transmission ECU 350 starts the process of supplying electric power to the vehicle 100. Also, the electric power transmission ECU 350 outputs the power supply signal CHG to the vehicle ECU 160 so that the charging of the power storage device 110 is started.

[0087] If the absolute value of the difference between the value of the supplied electric power PS and the value of the received electric power PR is larger than the threshold value a (YES in S130), the electric power transmission ECU 350 determines that there is a possibility that electric power stealing or electric leakage is occurring. Then, the control proceeds to S145. In S145, the electric power transmission ECU 350 sets the power supply signal CHG to OFF, to stop the supply of electric power.

[0088] Then, in S155, the electric power transmission ECU 350 outputs the control signal SE10 to open the relay RY10, and thus, stops the supply of electric power to the ehicle 100. Also, the electric power transmission ECU 350 outputs the power supply signal CHG to the vehicle ECU 160 so that the vehicle ECU 160 opens the relay RY1 and stops the charging device 200 to stop the charging of the power storage device 110.

[0089] Then, in S165, the electric power transmission ECU 350 outputs the alarm signal ALM to the operating portion 310 so that the operating portion 310 outputs an alarm, that is, the operating portion 310 provides a visual indication using a lamp or a liquid crystal display, or provides an audible warning using a buzzer or a chime, in order to notify the operator that electric power stealing or electric leakage is occurring. The process of outputting the alarm in SI 65 is not indispensable to the invention, and may be omitted.

[0090] If it is determined that there is no unused portion of the charging fee in S100 (NO in S100), the control proceeds to S145. In S145, it is determined that the supply of electric power should be stopped as described above. Thus, the charging process is stopped in S155. Then, in S165, the electric power transmission ECU 350 executes the process of outputting the alarm in SI 65 to notify the operator that there is no unused portion of the charging fee.

[0091] In the charging system in which the vehicle is supplied with electric power from the external power source, it is possible to determine whether electric power stealing or electric leakage is occurring based on the value of the supplied electric power and the value of the received electric power, and to stop the supply of electric power to the vehicle if there is a possibility that electric power stealing or electric leakage is occurring, by executing the above-described control. Thus, it is possible to prevent electric power stealing, and to detect electric leakage during the supply of electric power.

First modified example of the first embodiment

[0092] In the above-described first embodiment, the configuration is such that communication is performed between the vehicle 100 and the power supply device 300 using the communication line 440 for exclusive purpose included in the charging cable 400. However, the configuration for communication between the vehicle 100 and the power supply device 300 is not limited to this configuration. Other communication means may be employed. Hereinafter, modified examples of the communication method will be described.

[0093] FIG. 7 is a block diagram showing the entire charging system 10 in the case where wireless communication is employed as the communication means.

[0094] In FIG 7, the communication portion 170 in the vehicle 100 and the communication portion 320 included in the power supply device 300 in FIG. 2 are replaced with a communication portion 170A and a communication portion 320A, respectively. The communication portion 170A and the communication portion 320A can perform wireless communication. Accordingly, the communication line 440 in the charging cable 400 is unnecessary. The description of the elements shown in both of FIG. 2 and FIG. 7 will not be repeated.

[0095] In the method of wireless communication between the communication portion 170 A and the communication portion 320 A, a known technique using radio waves, light, infrared ray, or the like may be employed.

[0096] FIG. 8 is a block diagram showing the entire charging system 10 in the case where Power Line Communication (PLC) using the power line 430 included in the charging cable 400 is employed as the communication means.

[0097] In FIG. 8, power line communication modules 240 and 370 are added instead of the communication portion 170 in the vehicle 100 and the communication portion 320 in the power supply device 300 in FIG 2. The power line communication module 240 transmits and receives the control signals to and from the power lines ACL1 and ACL2. The power line communication module 370 transmits and receives the control signals to and from the power lines ACL10 and ACL20. Accordingly, the communication line 440 in the communication cable 400 is unnecessary. In FIG. 8, the description of the elements shown in both of FIG 2 and FIG. 8 will not be repeated.

[0098] The power line communication module 240 included in the vehicle 100 is connected to the power lines ACL1 and ACL2. The power line communication module 240 transmits the control signals output from the vehicle ECU 160, to the power lines ACL1 and ACL2, and to the power supply device 300 through the power line 430 in the charging cable 400. Also, the power line communication module 240 receives the control signals transmitted from the power supply device 300 through the power line 430, and outputs the control signals to the vehicle ECU 160.

[0099] The power line communication module 370 included in the power supply device 300 is connected to the power lines ACL10 and ACL20. The power line communication module 370 transmits the control signals output from the electric power transmission ECU 350, to the power lines ACL10 and ACL20, and to the vehicle 100 through the power line 430 in the charging cable 400. Also, the power line communication module 370 receives the control signals transmitted from the vehicle 100 through the power line 430, and outputs the control signals to the electric power transmission ECU 350.

[0100] As described above, in the case where the wireless communication or the power line communication is employed as the communication means, it is possible to prevent electric power stealing, and to detect electric leakage during the supply of electric power, by executing the control described in the first embodiment.

Second modified example of the first embodiment

[0101] In the above description, the operating portion, through which the charging fee and the like are input, is provided in the power supply device 300. However, the operating portion may be provided in the vehicle 100.

[0102] FIG. 9 is a block diagram showing the entire charging system 10 in the case where the operating portion is provided in the vehicle. In FIG. 9, an operating portion 180 is provided in the vehicle 100, instead of the operating portion 310 in the power supply device 300 in FIG 2. The description of the elements shown in both of FIG 2 and FIG. 9 will not .be repeated.

[0103] The operating portion 180 is an operating interface through which the charging operator inputs the charging fee and the like when the charging operator performs the operation for charging, and which displays an unused portion of the charging fee, and the charged state. For example, the operating portion 180 is configured to include a navigation system and/or an Electric Toll Collecting (ETC) device that is(are) included in the vehicle. The operating portion 180 outputs the information INP regarding the charging fee input based on the operation performed by the operator, to the vehicle ECU 160. Also the operating portion 180 outputs the charged state, and outputs an alarm when an abnormal situation occurs.

[0104] FIG 10 is a functional block diagram used to explain the power supply determination control executed by the vehicle ECU 160 and the electric power transmission ECU 350 in the case where the operating portion is provided in the vehicle. In FIG. 10, the functions of the operating portion 310 and the charging fee determination portion 351 in the power supply device 300 in the first embodiment in FIG. 5 are transferred to the operating portion 180 and a charging fee determination portion 163 in the vehicle 100, respectively.

[0105] The functions of the operating portion 180 and the charging fee determination portion 163 are basically the same as the functions of the operating portion 310 and the charging fee determination portion 351 in the power supply device 300, except that information (for example, the value of the supplied electric power PS, the determination flag FLG, and the alarm signal ALM) is communicated between the operating portion 180 and the charging fee determination portion 163, and the electric power transmission ECU 350 through the communication portions 170 and 320. Therefore, the description of these portions will not be repeated.

[0106] In FIG. 10, the charging fee determination portion 163 is provided in the vehicle 100. However, only the operating portion 180 may be provided in the vehicle 100, and the charging fee determination portion may be provided in the power supply device 300 as shown in FIG 2. Further, operating portions may be provided in both of the power supply device 300 and the vehicle 100, respectively, and it may be determined whether there is an unused portion of the charging fee based on information input from one or both of the operating portions.

Second embodiment

[0107] In the first embodiment and the modified examples of the first embodiment, the determination as to whether to permit the supply of electric power is made in the power supply device 300.

[0108] In a second embodiment, a configuration in which the vehicle ECU 160 in the vehicle 100 determines whether to permit the supply of electric power will be described.

[0109] FIG. 11 is a functional block diagram used to explain the power supply determination control executed by the vehicle ECU 160 and the electric power transmission ECU 350 in the charging system according to the second embodiment. In FIG. 11, the function of the power supply determination portion 353 in the functional block diagram in the second modified example of the first embodiment shown in FIG. 10 is transferred to a power supply determination portion 164 in the vehicle 100. The description of the functional blocks shown in both of FIG. 2 and FIG. 11, or in both of FIG. 10 and FIG. 11 will not be repeated.

[0110] The power supply determination portion 164 receives the value of the received electric power PR from the electric power computation portion 161, receives the determination flag FLG from the charging fee determination portion 163, and receives the value of the supplied electric power PS that has been computed by the electric power transmission ECU 350 and received by the communication portion 170: Then, the power supply determination portion 164 determines whether to permit the supply of electric power to the vehicle 100, based on the received information.

[0111] More specifically, if the determination flag FLG is OFF (that is, if there is no unused portion of the charging fee), the power supply determination portion 164 prohibits the supply of electric power. If the determination flag FLG is ON (that is, if there is an unused portion of the charging fee), the power supply determination portion 164 determines whether electric power stealing or electric leakage is occurring by determining whether the difference between the value of the supplied electric power PS and the value of the received electric power PR is larger than the predetermined threshold value a. Then, if the difference between the value of the supplied electric power PS and the value of the received electric power PR is equal to or smaller than the predetermined threshold value a, the power supply determination portion 164 permits the supply of electric power from the power supply device 300 to the vehicle 100. If the difference between the value of the supplied electric power PS and the value of the received electric power PR is larger than the predetermined threshold value a, the power supply determination portion 164 prohibits the supply of electric power to the vehicle 100. The power supply determination portion 164 generates the power supply signal CHG based on the result of the determination. Then, the power supply determination portion 164 outputs the power supply signal CHG to the charging control portion 162, and transmits the power supply signal CHG to the electric power transmission ECU 350 through the communication portion 170. [0112] If the supply of electric power is prohibited based on the result of the above-described determination, the power supply determination portion 164 outputs the alarm signal ALM to the operating portion 180, to notify the operator that the supply of electric power is prohibited. In response to the alarm signal ALM, the operating portion 180 outputs a visual warning using a lamp or a display unit, or outputs an audible warning using a buzzer or a chime.

[0113] In the power supply device 300, the electric power computation portion 352 receives the detected value of the voltage VS and the detected value of the electric current IS from the voltage sensor 330 and the electric current sensor 340, respectively. The electric power computation portion 352 computes the value of the supplied electric power PS based on the received information, and outputs the result of the computation to the vehicle ECU 160 through the communication portion 320. The relay control portion 354 generates the control signal SE10 based on the power supply signal CHG received by the communication portion 320, thereby controlling the relay RY10.

[0114] In the second embodiment, the relays RY1 and RY10 and the charging device 200 are controlled so that electric power is supplied for testing for a short time period, in order to compute the value of the supplied electric power PS and the value of the received electric power PR, before the power supply determination portion 164 determines whether to permit the supply of electric power, as in the first embodiment.

[0115] FIG 12 is a flowchart used to explain in detail the power supply determination control executed by the vehicle ECU 160 in the second embodiment. Each step in the flowchart in FIG. 12 is implemented when a program stored in advance in the vehicle ECU 160 is invoked by a main program and executed at predetermined time intervals or when a predetermined condition is satisfied. Alternatively, some steps may be implemented by hardware (an electronic circuit) for exclusive use.

[0116] As shown in FIG 12, when the vehicle ECU 160 recognizes that the charging cable 400 is connected to the vehicle 100 and the power supply device 300, the vehicle ECU 160 determines whether there is un unused portion of the charging fee input by the operator in S200. [0117] If there is an unused portion of the charging fee (YES in S200), the control proceeds to S210. In S210, the vehicle ECU 160 executes the control to supply electric power for testing as described above, and computes the value of the received electric power PR based on the values detected by the voltage sensor 210 and the electric current sensor 220. Then, in S220, the vehicle ECU 160 acquires the value of the supplied electric power PS from the electric power transmission ECU 350 through the communication portion 170.

[0118] Then, in S230, the vehicle ECU 160 determines whether the absolute value of the difference between the value of the supplied electric power PS and the value of the received electric power PR is larger than the predetermined threshold value a.

[0119] If the absolute value of the difference between the value of the supplied electric power PS and the value of the received electric power PR is equal to or smaller than the predetermined threshold value a (NO in S230), the vehicle ECU 160 determines that no electric power stealing is occurring and no electric leakage is occurring. Then, the control proceeds to S240. In S240, the vehicle ECU 160 permits the supply of electric power and sets the power supply signal CHG to ON.

[0120] Then, in S250, the vehicle ECU 160 starts the process of supplying electric power to the vehicle 100 by outputting the power supply signal CHG to the electric power transmission ECU 350. Also, the vehicle ECU 160 starts the charging of the power storage device 110 by outputting the control signal PWD to the charging device 200.

[0121] If the absolute value of the difference between the value of the supplied electric power PS and the value of the received electric power PR is larger than the predetermined threshold value a (YES in S230), the vehicle ECU 160 determines that there is a possibility that electric power stealing or electric leakage is occurring. Then, the control proceeds to S245. In S245, the vehicle ECU 160 sets the power supply signal CHG to OFF, to stop the supply of electric power.

[0122] Then, in S255, the vehicle ECU 160 outputs the power supply signal CHG to the electric power transmission ECU 350 so that the relay RY10 is opened, and thus, the supply of electric power to the vehicle 100 is stopped. Also, the vehicle ECU 160 outputs the control signal SE2 to open the relay RY1 and stops the charging device 200 so that the charging of the power storage device 110 is stopped.

[0123] Then, in S265, the vehicle ECU 160 outputs the alarm signal ALM to the operating portion 180 so that the operating portion 180 outputs an alarm, that is, the operating portion 180 provides a visual indication using a lamp or a liquid crystal display, or provides an audible warning using as a buzzer or a chime, in order to notify the operator that electric power stealing or electric leakage is occurring. The process of outputting the alarm in S265 is not indispensable to the invention, and may be omitted.

[0124] If there is no unused portion of the charging fee in S200 (NO in S200), the control proceeds to S245. In S245, it is determined that the supply of electric power should be stopped. Thus, the charging process is stopped in S255. Then, in S265, the vehicle ECU 160 executes the process of outputting the alarm to notify the operator that there is no unused portion of the charging fee.

[0125] In the configuration in which the determination as to whether to permit the supply of electric power is made in the vehicle 100, it is possible to determine whether electric power stealing or electric leakage is occurring based on the difference between the value of the supplied electric power and the value of the received electric power, and to stop the supply of electric power to the vehicle if there is a possibility that electric power stealing or electric leakage is occurring, by executing the above-described control. Thus, it is possible to prevent electric power stealing, and to detect electric leakage during the supply of electric power.

Modified example of the second embodiment

[0126] In the second embodiment as well, the power supply determination portion and the operating portion may be provided in different devices. That is, the power supply determination portion may be provided in the vehicle, and the operating portion may be provided in the power supply device.

[0127] FIG. 13 is a functional block diagram used to explain the power supply determination control executed by the vehicle ECU 160 and the electric power transmission ECU 350 in the charging system according to a modified example of the second embodiment. In FIG. 13, the functions of the operating portion 180 and the charging fee determination portion 163 in the second embodiment shown in FIG. 11 are transferred to the operating portion 310 and the charging fee determination portion 351 in the power supply device 300, respectively.

[0128] The modified example of the second embodiment is basically the same as the second embodiment, except that the determination flag FLG is output from the charging fee determination portion 351 to the vehicle ECU 160 through the communication portion 320, and the alarm signal ALM is output from the vehicle ECU 160 and received by the operating portion 310 through the communication portion 320. Therefore, the detailed description of the modified example of the second embodiment will not be repeated. '

[0129] Only the function of the operating portion 310 may be provided in the power supply device 300, and the function of the charging fee determination portion may be provided in the vehicle ECU 160.

[0130] Thus, in the configuration in which the operating portion 310 is provided in the power supply device 310, and the determination as to whether to permit the supply of electric power is made in the vehicle 100, it is possible to determine whether electric power stealing or electric leakage is occurring based on the value of the supplied electric power and the value of the received electric power, and to stop the supply of electric power to the vehicle if there is a possibility that electric power stealing or electric leakage is occurring. Thus, it is possible to prevent electric power stealing, and to detect electric leakage during the supply of electric power.

[0131] The configuration in which electric power is supplied from the power supply device 300 to the vehicle 100 using the charging cable 400 has been described. However, the configuration for the supply of electric power from the power supply device 300 to the vehicle 100 is not limited to this configuration. A configuration in which electric power is supplied in a non-contact manner may be employed. In this case, because the charging cable 400 is not provided, wireless communication may be employed as the communication between the power supply device 300 and the vehicle 100.

[0132] Each of the electric power transmission ECU 350 and the vehicle ECU 160 in the embodiments is one example of "the control device" according to the invention. The relay RY10 in the embodiments is one example of "the switch" according to the invention.

[0133] While the invention has been described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the exemplary embodiments or constructions. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the exemplary embodiments are shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the invention.