WO2011154815A2

WO2011154815A2 - Vehicle charging system and electric vehicle

Info

Publication number: WO2011154815A2
Application number: PCT/IB2011/001290
Authority: WO
Inventors: Wanleng Ang
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2010-06-11
Filing date: 2011-06-09
Publication date: 2011-12-15
Also published as: JP2011259658A; WO2011154815A3

Abstract

An adaptor (40) changes the frequency of a pilot signal (CPLT) sent to a charging ECU (18) of a vehicle (10), according to the type of an external electric power source (50) connected to the adaptor (40) (a solar battery (50A), an electric power supply system (50B), etc.). The charging ECU (18) of the vehicle (10) identifies the type of the external electric power source (50) on the basis of the frequency of the pilot signal (CPLT) from the adaptor (40). Then, the charging ECU (18) controls a charger (16) according to the identified type of The external electric power source (50). The charger (16), on the basis of a signal PWC from the charging ECU (18), converts the voltage of electric power supplied from the external electric power source (50), and charges an electricity storage device (12) with the voltage-converted electric power.

Description

VEHICLE CHARGING SYSTEM AND ELECTRIC VEHICLE

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The invention relates to a vehicle charging system and to an electric vehicle. In particular, the invention relates to a vehicle charging system for charging an electricity storage device mounted in a vehicle from an external electric power source, and to an electric vehicle equipped with the charging system.

2. Description of the Related Art

[0002] Japanese Patent Application Publication No. 8-19193 (JP-A-8-19193) discloses a simplified solar photovoltaic power generation system for home use. This solar photovoltaic power generation system includes a household power conditioner, and a battery charger. The power conditioner converts the direct-current electric power generated by a solar battery module into alternating-current electric power, and supplies the alternating-current electric power to household loads. The battery charger re-converts the alternating-current electric power from the power conditioner into direct-current electric power, and supplies the direct-current electric power to a battery of a gasoline motor vehicle or an electric vehicle, or converts power stored in the battery into alternating-current electric power, and supplies it to the household loads.

[0003] According to this solar photovoltaic power generation system, electric power generated by the solar battery module can be stored in the battery of a gasoline motor vehicle or an electric motor vehicle, and the electric power stored therein can be converted into alternating-current power, and therefore can be supplied to household loads, by using the battery charger.

[0004] In recent years, electric vehicles, such as electric motor vehicles, hybrid motor vehicles, etc., are drawing attention as vehicles friendly to the environment. These vehicles are equipped with an electric motor that generates vehicle-driving force, and an electricity storage device that stores electric power that is to be supplied to the electric motor. The hybrid motor vehicles are generally equipped with an electric motor and an internal combustion engine as motive power sources.

[0005] Among the foregoing vehicles, there is a known vehicle whose electricity storage device for driving the vehicle is able to be charged from a common household electric power supply. For example, by interconnecting an electrical receptacle provided in a house and a charging jack provided in a vehicle via a charging cable, electric power is supplied from an ordinary household electric power supply to the electricity storage device of the vehicle. The vehicle whose electricity storage device is chargeable from an external electric power source is also referred to as "plug-in vehicle". Incidentally, standards of the plug-in vehicle have been established in "SAE Electric Vehicle Conductive Charge Coupler" and the like (see SAE Electric Vehicle Conductive Charge Coupler (United States), SAE standards, SAE International, November, 2001).

[0006] A promising external electric power source that can be used to charge the plug-in vehicles is the solar battery, which emits no greenhouse effect gas. The solar photovoltaic power generation system described in Japanese Patent Application Publication No. 8-19193 (JP-A-8-19193) mentioned above uses a solar battery module as an external electric power source, and is a useful system.

[0007] However, since the electric power generated by the solar battery module is dependent on weather, the use of only the solar battery module as an external electric power source has a possibility of failing to sufficiently charge the electricity storage device mounted in a vehicle. Therefore, it is important to make the electricity storage device mounted in a vehicle chargeable from various types of external electric power sources, including a commercial electric power supply system.

SUMMARY OF THE INVENTION

[0008] The invention provides a vehicle charging system and an electric vehicle that supports various types of external electric power sources.

[0009] A first aspect of the invention relates to a vehicle charging system for charging an electricity storage device mounted in a vehicle from an external electric power source, the vehicle charging system including: a charger that converts voltage of electric power supplied from the external electric power source and charges the electricity storage device with the electric power converted in voltage; a control portion for controlling voltage conversion performed by the charger; and an identification portion for identifying a type of the external electric power source. The control portion controls the voltage conversion of the charger according to the type of the external electric power source identified by the identification portion.

[0010] In the foregoing aspect of the invention, the control portion controls the voltage conversion of the charger based on an ampacity, a voltage and a current of the external electric power source that correspond to the type of the external electric power source identified by the identification portion.

[0011] In the foregoing aspect, the vehicle charging system may further include a signal generation circuit which generates a control signal (pilot signal CPLT) that is modulated in pulse width according to magnitude of the current that is suppliable from the external electric power source to the vehicle, and which sends the control signal to the vehicle. The signal generation circuit may change frequency of the control signal according to the type of the external electric power source. The identification portion may identify the type of the external electric power source based on the frequency of the control signal from the signal generation circuit.

[0012] In the foregoing aspect, the external electric power source may include a plurality of electric power sources. The signal generation circuit may generate the frequency of the control signal according to the type of the electric power connected to the charger. When more than one of the plurality of electric power sources are connected to the charger, the signal generation circuit may generate the control signal in which frequencies commensurate with the types of the electric power sources sequence at a predetermined interval.

[0013] In the foregoing aspect, the signal generation circuit may change a duty ratio of the frequency of the control signal according to a limit of charging current commensurate with the type of the external electric power source.

[0014] In the foregoing aspect, the external electric power source may include a plurality of electric power sources. The vehicle charging system may further include a switching portion provided between the charger and the plurality of electric power sources, and a selection portion that selects an electric power source amoung the plurality of electric power sources. The switching portion may electrically connect the electric power source selected by the selection portion to the charger, and may electrically disconnect the electric power source that is not selected by the selection portion from the charger.

[0015] In the foregoing aspect, the plurality of electric power sources may include an electric power supply system, and an electricity generation apparatus that is provided outside the vehicle. The selection portion may select the electricity generation apparatus when the voltage of the electricity generation apparatus is higher than a predetermined voltage, and may select the electric power supply system when the voltage of the electricity generation apparatus is lower than or equal to the predetermined voltage and the voltage of the electric power supply system is within a predetermined range.

[0016] In the foregoing aspect, the control portion may stop charging of the electricity storage device when the voltage of the electricity generation apparatus is lower than or equal to the predetermined voltage and the voltage of the electric power supply system is outside the predetermined range.

[0017] In the foregoing aspect, the electricity generation apparatus may include a solar cell.

[0018] In the foregoing aspect, the external electric power source may include a plurality of electric power sources, and the plurality of electric power sources may include an electric power supply system and an electricity generation apparatus that is provided outside the vehicle.

[0019] A second aspect of the invention relates to an electric vehicle that includes: an electricity storage device, an electric motor that receives electric power from the electricity storage device and that generates vehicle driving force, a charger that converts voltage of the electric power supplied from an external electric power source that charges the electricity storage device with the electric power converted in voltage, and a control device for controlling the charger. The control device includes: an identification portion for identifying a type of the external electric power source; and a charging control portion that controls the charger according to the type of the external electric power source identified by the identification portion, when the electricity storage device is charged from the external electric power source.

[0020] In this aspect, the control device may control voltage conversion of the charger based on an ampacity, a voltage and a current of the external electric power source that correspond to the type of the external electric power source identified by the identification portion.

[0021] Furthermore, in the foregoing aspect, a signal generation circuit which generates a control signal (pilot signal CPLT) that is modulated in pulse width according to magnitude of the current that is suppliable from the external electric power source to the electric vehicle, and which sends the control signal to the electric vehicle is provided outside the electric vehicle. The signal generation circuit may change frequency of the control signal according to the type of the external electric power source. The identification portion may identify the type of the external electric power source based on the frequency of the control signal from the signal generation circuit.

[0022] In the foregoing aspect, the external electric power source may include a plurality of electric power sources. The signal generation circuit may generate the frequency of the control signal according to the type of the electric power source connected to the charger. When more than one of the plurality of electric power sources are connected to the charger, the signal generation circuit may generate the control signal in which frequencies commensurate with the types of the electric power sources sequence at a predetermined interval.

[0023] In the foregoing aspect, the signal generation circuit may change a duty ratio of the frequency of the control signal according to a limit of charging current commensurate with the type of the external electric power source.

[0024] In the foregoing aspect, the external electric power source may include a plurality of electric power sources. A switching portion provided between the charger and the plurality of electric power sources may be provided outside the electric vehicle. The control device may further include a selection portion that selects an electric power source moung the plurality of electric power sources. The switching portion may electrically connect the electric power source selected by the selection portion to the charger, and may electrically disconnect the electric power source that is not selected by the selection portion from the charger.

[0025] In the foregoing aspect, the plurality of electric power sources may include an electric power supply system, and an electricity generation apparatus that is provided outside the electric vehicle. The selection portion may select the electricity generation apparatus when the voltage of the electricity generation apparatus is higher than a predetermined voltage, and may select the electric power supply system when the voltage of the electricity generation apparatus is lower than or equal to the predetermined voltage and the voltage of the electric power supply system is within a predetermined range.

[0026] In the foregoing aspect, the control portion may stop charging of the electricity storage device when the voltage of the electricity generation apparatus is lower than or equal to the predetermined voltage and the voltage of the electric power supply system is outside the predetermined range.

[0027] In the foregoing aspect, the electricity generation apparatus may include a solar cell. [0028] In the foregoing aspect, the external electric power source may include a plurality of electric power sources, and the plurality of electric power sources may include an electric power supply system and an electricity generation apparatus that is provided outside the electric vehicle.

[0029] According to the foregoing aspects, the identification portion identifies the type of the external electric power source, and the charger is controlled according to the identified type of the external electric power source. Therefore, there is no need to construct charging circuits separately for each type of external electric power source or to provide a plurality of chargers. Therefore, according to this invention, a vehicle charging system that supports various types of external electric power sources can be realized in a small size at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The foregoing and further 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 block diagram that shows the overall structure of a vehicle charging system according to a first embodiment of the invention;

FIG. 2 shows a vehicle charging system in which the external electric power source is a solar battery;

FIG. 3 shows a vehicle charging system in which the external electric power source is an electric power supply system;

FIG. 4 is a more detailed diagram of the charging mechanism in a vehicle charging system;

FIG. 5 shows the waveform of a pilot signal;

FIG. 6 shows an example of the relation among the type of external electric power source and the frequency of the pilot signal;

FIG. 7 shows the relation between the duty ratio of the pilot signal and the maximum current that a charging cable is able to conduct;

FIG. 8 is a timing chart of the pilot signal and switches;

FIG. 9 is a function block diagram of a CPU shown in FIG. 4;

FIG. 10 is a circuit diagram of an example charger;

FIG. 11 is a flowchart illustrating the processes executed by a charging ECU when switching a charging control in accordance with the type of external electric power source;

FIG. 12 is a block diagram schematically showing an overall construction of a vehicle charging system according to a second embodiment of the invention;

FIG. 13 is a diagram showing a construction in the case where a solar battery and an electric power supply system, as external electric power sources, are connected to an adaptor;

FIG. 14 is a diagram showing a construction of the adaptor shown in FIG. 13;

FIG. 15 is a diagram showing an example of a relation between the states of connection of external electric power sources and the frequency of the pilot signal;

FIG. 16 is a function block diagram of a CPU that is included in a charging ECU in the second embodiment; and

FIG. 17 is a flowchart illustrating a processing procedure of the charging ECU regarding selection of an external electric power source.

DETAILED DESCRIPTION OF EMBODIMENTS

[0031] Hereinafter, embodiments of the invention will be described in detail hereinafter with reference to the drawings. The same or comparable portions are denoted by the same reference characters in the drawings, and will not be redundantly described below.

[0032] FIG. 1 is a schematic block diagram that shows the overall structure of a vehicle charging system according to a first embodiment of the invention. Referring to FIG. 1, a vehicle charging system 100 includes a vehicle 10, a charging cable 30, an adaptor 40, and an external electric power source 50. The vehicle 10 includes an electric storage device 12, a motive power output device 14, a charger 16, a charging ECU (electronic control unit) 18, and an inlet 20.

[0033] The electricity storage device 12 is a rechargeable direct-current electric power supply, and is made up of a secondary battery, for example, a lithium ion battery, a nickel metal hydride battery, etc. The electricity storage device 12 stores not only electric power supplied from the charger 16 but also regenerative electric power generated by the motive power output device 14. The electricity storage device 12 supplies stored electric power to the motive power output device 14. Alternatively, the electricity storage device 12 may also be a high-capacity capacitor. Moreover, the electricity storage device 12 may be any device as long as it is an electric power buffer capable of temporarily storing electric power supplied from the external electric power source 50 and also storing regenerative electric power from the motive power output device 14, and of supplying stored electric power to the motive power output device 14.

[0034] The motive power output device 14 propels the vehicle 10 using the electric power stored in the electricity storage device 12. Although not particularly shown in the drawings, the motive power output device 14 includes, for example, an inverter that receives electricity from the electricity storage device 12, an electric motor that is driven by the inverter, driving wheels that receive drive force from the motor, etc. In addition, the motive power output device 14 may include an electric generator for charging the electricity storage device 12, and an engine capable of driving the electricity generator.

[0035] The charger 16 is provided between the inlet 20 and the electricity storage device 12. In accordance with a signal PWC from the charging ECU 18, the charger 16 converts the electric power supplied from the external electric power source 50to a voltage level that is appropriate for the electric storage device 12. The charger 16 then outputs the voltage-converted electric power to the electric storage device 12.

[0036] If the electric storage device 12 is to be charged by the external electric power source 50, the charging ECU 18 generates the signal PWC for driving the charger 16, and outputs the generated signal PWC to the charger 16. The charging ECU 18 identifies the type of the external electric power source 50 on the basis of a pilot signal (described below) that the charging ECU 18 receives from the adaptor 40 via the charging cable 30 and a signal line SL, and controls the charger 16 according to the identified type of the external electric power source 50.

[0037] The inlet 20 is an interface for connecting the charging cable 30 to the vehicle 10. When the charging cable 30 is connected to the inlet 20, the inlet 20 notifies the connection thereto to the charging ECU 18. While the charging cable 30 is connected, the inlet 20 gives electricity received via the charging cable 30, to the charger 16. Besides, the inlet 20 transmits signals between the charging cable 30 and the signal line SL connected to the charging ECU 18. The charging cable 30 is an electric power line for supplying electric power from the external electric power source 50 to the vehicle 10. Besides, the charging cable 30 is also used as a communication medium between the vehicle 10 and the adaptor 40 that is provided on the charging cable 30.

[0038] The adaptor 40 is provided on the charging cable 30, and is connected to the external electric power source 50. The adaptor 40 generates the pilot signal (described below) for exchanging predetermined information with the vehicle 10 via the charging cable 30. Concretely, using the pilot signal, the adaptor 40 is able to transmit to the vehicle 10 information regarding the rated electric current value of the charging cable 30, the type of the external electric power source 50 that is connected to the adaptor 40, the state of the vehicle 10, etc. Besides, the adaptor 40 includes a relay capable of disconnecting an electrical path provided in the charging cable 30, and switches on and off the relay according to the command received from the vehicle 10 side through the use of the pilot signal.

[0039] Incidentally, the external electric power source 50 and the adaptor 40 may be separable from each other, and may also be constructed in an integrated fashion. Likewise, the adaptor 40 and the charging cable 30 may be separable from each other, and may also be constructed in an integrated fashion. The construction of the adaptor 40 will be later described in detail. The external electric power source 50 is a source that supplies electric power to the vehicle 10, and may be any one of various electric power sources, including a commercial electric power supply system, a solar battery, an aerogeneration apparatus, etc.

[0040] In the vehicle charging system 100, the adaptor 40 generates a signal (pilot signal) with which it is possible to distinguish the type of the external electric power source 50 that is connected to the adaptor 40, and outputs the generated signal to the charging ECU 18 of the vehicle 10 via the charging cable 30, the inlet 20 and the signal line SL. Then, the charging ECU 18 identifies the type of the external electric power source 50 on the basis of the signal from the adaptor 40, and controls the charger 16 according to the identified type of the external electric power source 50.

[0041] FIG. 2 is a diagram showing a construction in the case where the external electric power source 50 is a solar battery. Referring to FIG. 2, a solar battery 50A and an adaptor 40A are examples of the external electric power source 50 and the adaptor 40, respectively, that are shown in FIG. 1. The solar battery 50A is connected to the adaptor 40A. The solar battery 50A generates direct-current electric power from sunlight. Incidentally, the output of the solar battery 50A greatly depends on the amount of solar radiation.

[0042] Using the pilot signal (described later) that is output to the vehicle 10 (not shown in FIG. 2) via the charging cable 30, the adaptor 40A notifies the vehicle 10 that the external electric power source 50 is the solar battery 50A. A distal end of the charging cable 30 is provided with a connector 60 that is able to connect the charging cable 30 to the inlet 20 (not shown in FIG. 2) of the vehicle 10.

[0043] FIG. 3 is a diagram showing a construction in the case where the external electric power source 50 is an electric power supply system. Referring to FIG. 3, an electric power supply system 50B and an adaptor 40B are examples of the external electric power source 50 and the adaptor 40, respectively, which are shown in FIG. 1. The electric power supply system 50B is connected to the adaptor 40B by connecting a plug 62 of the adaptor 40B to a receptacle of the electric power supply system 50B. The electric power supply system 50B stably supplies commercial alternating-current electric power. The adaptor 40B notifies the vehicle 10 that the external electric power source 50 is the electric power supply system 50B using the pilot signal output to the vehicle 10 (not shown in FIG. 3).

[0044] FIG. 4 shows the charging mechanism of the vehicle charging system 100 in more detail. Referring to FIG. 4, the charging cable 30 is connected to the inlet 20 of the vehicle 10 by the connector 60. The connector 60 is provided with a limit switch 112. When the connector 60 is connected to the inlet 20, the limit switch 112 is activated. Then, a cable connection signal PISW whose signal level changes with activation of the limit switch 112 is input to the charging ECU 18 of the vehicle 10.

[0045] The adaptor 40 includes a charging circuit interrupt device (CCID) relay 120, a control pilot circuit 122, a power supply circuit 130. The CCID relay 120 is provided on a pair of power lines within the charging cable 30, and switched on and off by the control pilot circuit 122. The power supply circuit 130 converts the electric power supplied from the external electric power source 50 to the operating electric power of the control pilot circuit 122, and outputs the converted electric power to the control pilot circuit 122.

[0046] The control pilot circuit 122 generates a pilot signal CPLT. The generated pilot signal CPLT is transmitted to the charging ECU 18 of the vehicle 10 via the connector 60, the inlet 20 and a control pilot line SL1. Through the use of this pilot signal CPLT, the type of the external electric power source 50 and the ampacity of the charging cable 30 (i.e., rated current of the charging cable 30) is notified from the adaptor 40 to the vehicle 10, and the CCID relay 120 is remotely controlled from the vehicle 10. That is, the electric potential of the pilot signal CPLT is manipulated in the vehicle 10. Based on changes in the electric potential of the pilot signal CPLT, the control pilot circuit 122 controls the CCID relay 120.

[0047] The control pilot circuit 122 includes an oscillator 124, a resistance element Rl, and a voltage sensor 126. The oscillator 124 outputs a non-oscillating signal when the electric potential of the pilot signal CPLT that is detected by the voltage sensor 126 is in the vicinity of a prescribed potential VI (e.g., 12 V). Besides, if the potential of the pilot signal CPLT declines from the potential .VI, the oscillator 124 outputs an oscillating signal that has a frequency commensurate with the type of the external electric power source 50 and that has a prescribed duty ratio.

[0048] For example, when the external electric power source 50 is the solar battery 50A, the oscillator 124 provided in the adaptor 40A as an example of the adaptor 40 generates a signal of a frequency fl . When the external electric power source 50 is the electric power supply system 50B, the oscillator 124 provided in the adaptor 40B as an example of the adaptor 40 generates a signal of a frequency f2. Besides, the duty ratio of the pilot signal CPLT is set on the basis of the limit value of the electric current that the charging cable 30 is able to conduct.

[0049] FIG. 5 is a diagram showing a waveform of the pilot signal CPLT. Referring to FIG. 5, the pilot signal CPLT oscillates with a period T that is commensurate with the type of the external electric power source 50. Using the period T (frequency 1/T), the type of the external electric power source 50 is notified to the charging ECU 18 of the vehicle 10. Besides, the duty ratio of the pilot signal CPLT is set on the basis of the electric current (ampacity) that can be supplied by the charging cable 30 from the external electric power source 50 to the vehicle 10. Using the duty ratio, the electric current value of the charging cable 30 is notified to the charging ECU of the vehicle 10.

[0050] FIG. 6 is a diagram showing an example of a relation between the type of the external electric power source 50 and the frequency of the pilot signal CPLT. Referring to FIG. 6, in the case where the external electric power source 50 is the solar battery 50A, the adaptor 40A (shown in FIG. 2) that is connected to the solar battery 50A generates the pilot signal CPLT of the frequency fl (period Tl). Besides, in the case where the external electric power source 50 is the electric power supply system 50B, the adaptor 40B (shown in FIG. 3) that is connected to the electric power supply system 50B generates the pilot signal CPLT of the frequency f2 (period T2). Because the frequency (or period) of the pilot signal CPLT is detected on the vehicle 10 side, the type of the external electric power source 50 can be identified in the vehicle 10.

[0051] FIG. 7 is a diagram showing a relation between the duty ratio of the pilot signal CPLT and the limit of the electric current that the charging cable 30 is able to conduct. Referring to FIG. 7, the duty ratio of the pilot signal CPLT varies according to the ampacity of the charging cable 30. Because the duty ratio of the pilot signal CPLT is detected on the vehicle 10 side, the ampacity of the charging cable 30 can be detected in the vehicle 10.

[0052] Referring back to FIG. 4, if the electric potential of the pilot signal

CPLT declines to a vicinity of a prescribed electric potential V3 (e.g., 6 V), the control pilot circuit 122 turns on the CCID relay 120. The electric potential of the pilot signal CPLT is manipulated by switching the resistance value of a resistance circuit 180 (described later) in the charging ECU 18 of the vehicle 10.

[0053] On the vehicle 10 side, power lines PL between the inlet 20 and the charger 16 (FIG. 1) are provided with a DFR (dead front relay) 150 and an LC filter 160. The DFR 150 is a relay for bringing about electrical connection/disconnection between the inlet 20 and the charger 16. The DFR 150 is switched on and off by a control signal from the charging ECU 18. The LC filter 160 is provided between the DFR 150 and the inlet 20, and prevents the high-frequency noise that occurs according to the switching action of the charger 16 from being output to the charging cable 30.

[0054] A voltage sensor 170 detects the voltage V of the external electric power source 50, and outputs the detected value of the voltage V to the charging ECU 18. The electric current sensor 172 detects the current I supplied from the external electric power source 50, and outputs the detected value of the current I to the charging ^■ ECU 18.

[0055] The charging ECU 18 includes the resistance circuit 180, input buffers 182 and 184, and a CPU (central processing unit). The resistance circuit 180 includes pull-down resistors R2 and R3, and switches SW1 and SW2. The pull-down resistor R2 and the switch SWl are connected in series between a vehicle's earth 188 and the control pilot line SL1 through which the pilot signal CPLT is sent. The pull-down resistor R3 and the switch SW2 are also connected in series between the vehicle's earth 188 and the control pilot line SL1. The switches SWl and SW2 are switched on and off according to a control signal from the CPU 186.

[0056] The electric potential of the pilot signal CPLT is manipulated by the

. resistance circuit 180. Concretely, when the connector 60 is connected to the inlet 20, the CPU 186 turns on the switch SWl, so that the resistance circuit 180 lowers the electric potential of the pilot signal CPLT to a prescribed potential V2 (e.g., 9 V) by using the pull-down resistor R2. Then, when the preparation for the charging is completed on the vehicle 10 side, the CPU 186 turns on the switch SW2, so that the resistance circuit 180 lowers the electric potential of the pilot signal CPLT to a prescribed voltage V3 by using the pull-down resistors R2 and R3. Thus, by manipulating the electric potential of the pilot signal CPLT through the use of the resistance circuit 180, the CCID relay 120 of the adaptor 40 can be remotely controlled by the charging ECU 18.

[0057] The input buffer 182 receives the pilot signal CPLT from the control pilot line SL1, and outputs the received pilot signal CPLT to the CPU 186. The input buffer 184 receives the cable connection signal PISW from a signal line SL2 that is connected to the limit switch 112 of the connector 60, and outputs the received cable connection signal PISW to the CPU 186.

[0058] Incidentally, voltage is applied to the signal line SL2 from the charging ECU 18. When the connector 60 is connected to the inlet 20, the limit switch 112 turns on, so that the electric potential of the signal line SL2 becomes equal to the ground level. That is, the cable connection signal PISW is a signal that becomes an L level (logical low level) when the connector 60 is connected to the inlet 20, and that becomes an H level (logical high level) when the connector 60 is not connected to the inlet 20.

[0059] The CPU 186 determines the presence or absence of the connection between the charging cable 30 and the vehicle 10 on the basis of the cable connection signal PISW. Concretely, the CPU 186 detects whether or not the inlet 20 and the connector 60 are interconnected, on the basis of the cable connection signal PISW from the input buffer 184. Upon detecting the connection between the inlet 20 and the connector 60 on the basis of the cable connection signal PISW, the CPU 186 turns on the switch SW1. Due to this, the electric potential of the pilot signal CPLT declines from VI, so that the pilot signal CPLT starts oscillating.

[0060] After the pilot signal CPLT starts oscillating, the CPU 186 identifies the type of the external electric power source 50 on the basis of the frequency of the pilot signal CPLT. For example, as described above, when the frequency of the pilot signal CPLT is fl, the external electric power source 50 is identified as the solar battery 50A, and when the frequency of the pilot signal CPLT is f2, the external electric power source 50 is identified as the electric power supply system 50B. Besides, the CPU 186 detects the limit of the electric current that is supplied from the charging cable 30, on the basis of the duty ratio of the pilot signal CPLT. [0061] When the charging preparation of the electricity storage device 12 is completed, the CPU 186 turns on the switch SW2. Due to this, the electric potential of the pilot signal CPLT declines to V3, and the CCID relay 120 in the adaptor 40 is turned on. After that, the CPU 186 turns on the DFR 150. Due to this, the electric power from the external electric power source 50 is given to the charger 16 (FIG. 1).

[0062] Then, the CPU 186 generates a signal PWC for controlling the charger 16in accordance with: the type of the external electric power source 50 as identified by the frequency of the pilot signal CPLT; the ampacity detected on the basis of the duty ratio of the pilot signal CPLT; the voltage V detected by the voltage sensor 170; and the electric current I detected by the electric current sensor 172.

[0063] FIG. 8 is a timing chart of the pilot signal CPLT and the switches SW1 and SW2. Referring to FIG. 8, at time tl, the supply of electric power from the external electric power source 50 to the adaptor 40 starts, and the control pilot circuit 122, receiving the electric power from the external electric power source 50, generates the pilot signal CPLT.

[0064] Incidentally, at this time point, the connector 60 of the charging cable 30 has not been connected to the inlet 20 of the vehicle side, and therefore the electric potential of the pilot signal CPLT is VI (e.g., 12 V), and the pilot signal CPLT is in a non-oscillating state.

[0065] At time t2 when the connector 60 is connected to the inlet 20, the electric potential of the pilot signal CPLT is lowered to V2 (e.g., 9 V) by the pull-down resistor R2 of the resistance circuit 180. Therefore, at time t3, the control pilot circuit 122 oscillates the pilot signal CPLT. After the preparation for the charging control is completed, the CPU 186 turns on the switch SW2 at time t4. Therefore, the electric potential of the pilot signal CPLT is further lowered to V3 (e.g., 6 V) by the pull-down resistor R3 of the resistance circuit 180.

[0066] After the pilot signal CPLT declines to V3, the control pilot circuit 122 turns on the CCID relay 120 of the adaptor 40. After that, the DFR 150 in the vehicle 10 is turned on, so that the charging of the electricity storage device 12 is executed from the external electric power source 50 through the use of the charger 16.

[0067] FIG. 9 is a function block diagram of the CPU 186 shown in FIG. 4. Referring to FIG. 9, the CPU 186 includes an identification portion 202 and a charging control portion 204. The identification portion 202 receives the pilot signal CPLT. Then, the identification portion 202 identifies the type of the external electric power source 50 on the basis of the frequency of the pilot signal CPLT. As described above, for example, the identification portion 202 identifies the external electric power source 50 as being the solar battery 50A when the frequency of the pilot signal CPLT is f 1 , and identifies the external electric power source 50 as being the electric power supply system 50B when the frequency of the pilot signal CPLT is f2.

[0068] The charging control portion 204 receives a detected value of the voltage V from the voltage sensor 170, and receives a detected value of the current I from the electric current sensor 172. Besides, the charging control portion 204 detects an ampacity on the basis of the duty ratio of the pilot signal CPLT. Then, the charging control portion 204 generates the signal PWC for controlling the charger 16 according to the type of the external electric power source 50 identified by the identification portion 202, on the basis of the detected values of the voltage V and the current I, in such a manner that the charging current does not exceed the ampacity. Specifically, in the case where the external electric power source 50 is the solar battery 50A and therefore the charger 16 is supplied with direct-current electric power, the charging control portion 204 generates the signal PWC so that the charger 16 operates as a DC/DC converter and so that, for example, a maximum electric power point tracking control (MPPT control) will be executed. Incidentally, for the maximum electric power point tracking control (MPPT control), it is possible to adopt various known control techniques. Besides, in the case where the external electric power source 50 is the electric power supply system 50B and therefore the charger 16 is supplied with alternating-current electric power, the charging control portion 204 generates the signal PWC so that the charger 16 operates as an AC/DC converter.

[0069] FIG. 10 is a circuit diagram showing an example of a construction of the charger 16. Referring to FIG. 10, the charger 16 includes voltage conversion circuits 310, 320 and 340, an isolation transformer 330, and a drive device 350.

[0070] Each of the voltage conversion circuits 310, 320 and 340 is made up of a single-phase bridge circuit. The voltage conversion circuit 310, on the basis of a drive signal from the drive device 350, converts the electric power given to the inlet 20 into direct-current electric power, and outputs the converted electric power to the voltage conversion circuit 320. Incidentally, the electric power given to the inlet 20 is direct-current electric power in the case where the external electric power source 50 is the solar battery 50A, and is alternating-current electric power in the case where the external electric power source 50 is the electric power supply system 50B. The voltage conversion circuit 320, on the basis of a drive signal from the drive device 350, converts the direct-current electric power supplied from the voltage conversion circuit 310 into high-frequency alternating-current electric power, and outputs the converted electric power to the isolation transformer 330.

[0071] The isolation transformer 330 includes a core made of a magnetic material, and a primary coil and a secondary coil that are wound around the core. The primary coil and the secondary coil are electrically insulated from each other, and are connected to the voltage conversion circuits 320 and 340, respectively. The isolation transformer 330 converts the high-frequency alternating-current electric power received from the voltage conversion circuit 320 into a voltage level commensurate with the turns ratio between the primary coil and the secondary coil, and outputs the converted electric power to the voltage conversion circuit 340. The voltage conversion circuit 340, on the basis of a drive signal from the drive device 350, converts the alternating-current electric power given from the isolation transformer 330 into direct-current electric power, and outputs the converted direct-current electric power to the electricity storage device 12.

[0072] The drive device 350, on the basis of the signal PWC from the charging ECU 18, generates drive signals for actually driving the voltage conversion circuits 310, 320 and 340, and outputs the generated drive signals to the voltage conversion circuits 310, 320 and 340.

[0073] FIG. 11 is a flowchart illustrating a processing procedure of the charging ECU 18 regarding the switching of the charging control commensurate with the type of the external electric power source 50. Referring to FIG. 11 , the charging ECU 18 receives the pilot signal CPLT, and detects the frequency of the pilot signal CPLT (step S 10). Next, the charging ECU 18 determines whether or not the detected frequency of the pilot signal CPLT is f 1 (step S20).

[0074] If it is determined that the frequency of the pilot signal CPLT is fl (YES in step S20), the charging ECU 18 identifies the external electric power source 50 as being the solar battery 50A, and sets the charging mode to a solar charging mode (step S30). Due to this, a charging control commensurate with the solar battery 50A (e.g., the MPPT control or the like) is executed.

[0075] On the other hand, if in step S20 it is determined that the frequency of the pilot signal CPLT is not fl (NO in step S20), the charging ECU 18 then determines whether or not the frequency of the pilot signal CPLT is f2 (step S40). [0076] If it is determined that the frequency of the pilot signal CPLT is f2 (YES in step S40), the charging ECU 18 identifies the external electric power source 50 as being the electric power supply system 50B, and sets the charging mode to a system charging mode (step S50). Due to this, a charging control commensurate with the electric power supply system 50B (e.g., a system coordinated control or the like) is executed.

[0077] As described above, in the first embodiment, the type of the external electric power source 50 is identified, and the charger 16 is controlled according to the identified type of the external electric power source 50. Therefore, there is no need to construct charging circuits separately for each type of external electric power source 50 nor to provide a plurality of chargers. Therefore, according to the first embodiment, a vehicle charging system that supports various external electric power sources can be realized in a small size at low cost.

[0078] Besides, in the first embodiment, the type of the external electric power source 50 is notified from the adaptor 40 to the vehicle 40, by using the pilot signal CPLT for use for notifying the ampacity of the charging cable 30 to the vehicle 10 and remotely controlling the CCID relay 120 from the vehicle 10. Therefore, there is no need to separately provide a signal line for notifying the type of the external electric power source 50 from the adaptor 40 to the vehicle 10. Therefore, in this respect, too, the charging system can be simplified and can be reduced in cost.

[0079] FIG. 12 is a block diagram schematically showing an overall construction of a vehicle charging system according to a second embodiment of the invention. Referring to FIG. 12, a vehicle charging system 100A includes a vehicle 10A, a charging cable 30, an adaptor 40C, and external electric power sources 50-1 and 50-2. The vehicle 10A includes a charging ECU 18A instead of the charging ECU 18 shown in FIG. 1, in a construction substantially the same as that of the vehicle 10 in the first embodiment shown in FIG. 1.

[0080] The adaptor 40C is provided on a charging cable 30, and is connectable to the external electric power sources 50-1 and 50-2. The adaptor 40C has substantially the same function as the adaptor 40 in the first embodiment, and, furthermore, notifies the vehicle 10A of the states of connection of the external electric power sources 50-1 and 50-2, and the voltage information about the external electric power sources that are connected to the adaptor 40C.

[0081] Besides, the adaptor 40C includes a switching portion that electrically connects one of the external electric power sources 50-1 and 50-2 and that electrically disconnects the other external electric power source, and therefore performs the electrical connection/disconnection of the external electric power sources 50-1 and 50-2 on the basis of a selection signal from the vehicle 10A. The construction of this adaptor 40C will be later described in detail. The external electric power sources 50-1 and 50-2 are electric power sources that are able to supply electric power to the vehicle 10A, and may be various electric power sources, including a commercial electric power supply system, a solar battery, an aerogeneration apparatus, etc.

[0082] At the time of charging the electricity storage device 12 from the external electric power source 50-1 or 50-2, the charging ECU 18A generates a signal PWC for driving the charger 16, and outputs the generated signal PWC to the charger 16. It is to be noted herein that the charging ECU 18A is notified, from the adaptor 40C, of the states of connection of the external electric power sources 50-1 and 50-2 and voltage information regarding the external electric power sources that are connected to the adaptor 40, and selects one of the external electric power sources 50-1 and 50-2 in accordance with a predetermined condition, on the basis of the information. Then, the charging ECU 18A outputs to the adaptor 40C a selection signal for electrically connecting the selected external electric power source, and controls the charger 16 according to the selected external electric power source 50.

[0083] In the vehicle charging system 100A according to the second embodiment, a plurality of external electric power sources can be connected to the adaptor 40C. The adaptor 40C generates a signal (pilot signal) capable of notifying the states of connection of external electric power sources, and outputs the generated signal to the charging ECU 18A of the vehicle 10A via the charging cable 30, the inlet 20 and the signal line SL. Besides, the adaptor 40C detects the voltage of the external electric power sources connected to the adaptor 40C, and outputs the thus-obtained voltage information about the external electric power sources to the charging ECU 18 A. The charging ECU 18 A, on the basis of the signal and the voltage information from the adaptor 40C, selects an external electric power source that is optimum for the charging of the electricity storage device 12, and notifies the adaptor 40C of the selected external electric power source. The adaptor 40C performs electrical connection/disconnection of the external electric power sources 50-1 and 50-2 on the basis of the selection signal received from the charging ECU 18A. Then, the charging ECU 18A controls the charger 16 according to the selected external electric power source.

[0084] FIG. 13 is a diagram showing a construction in the case where a solar battery and an electric power supply system, as external electric power sources, are connected to the adaptor 40C. Referring to FIG. 13, the solar battery 50A and the electric power supply system 50B are examples of the external electric power sources 50-1 and 50-2, respectively, that are shown in FIG. 12, and are both connected to the adaptor 40C.

[0085] The adaptor 40C notifies the vehicle 10A (not shown in FIG. 13) that the solar battery 50A and the electric power supply system 50B are connected to the adaptor 40C. Besides, the adaptor 40C notifies the vehicle 10A of voltage information regarding the solar battery 50A and the electric power supply system 50B. Furthermore, the adaptor 40C electrically connects one of the solar battery 50A and the electric power supply system 50B to the vehicle 10A, on the basis of the selection signal from the vehicle 10A.

[0086] FIG. 14 is a diagram showing a construction of the adaptor 40C shown in FIG. 13. Referring to FIG. 14, the adaptor 40C includes a CCID 420, relays 430 and 432, voltage sensors 440 and 442, and an inverter 450. Incidentally, the solar battery 50A is connected to terminals 410, and the electric power supply system 50B are connected to terminals 412.

[0087] The CCID 420 includes the CCID relay 120, the control pilot circuit

122 and the power supply circuit 130 that are shown in FIG. 4 (not shown in FIG. 14). Incidentally, in the second embodiment, the CCID 420 detects the states of connection of the solar battery 50A and the electric power supply system 50B on the basis of values detected by the voltage sensors 440 and 442, and changes the frequency of the pilot signal CPLT according to the states of connection. Besides, the CCID 420, on the basis of the detected values from the voltage sensors 440 and 442, outputs the voltage information about the solar battery 50A and the electric power supply system 50B to the charging ECU 18A of the vehicle 10A. Besides, other constructions of the CCID 420 are the same as in the adaptor 40 shown in FIG. 4.

[0088] The relay 430 is provided between the terminals 410 and the CCID

420, and is switched on and off according to the output of the inverter 450. The relay 432 is provided between the terminals 412 and the CCID 420, and is switched on and off according to a selection signal SELECT from the charging ECU 18 A of the vehicle 10A. The inverter 450 generates an inversion signal that is inverted from the selection signal SELECT, and outputs the generated inversion signal to the relay 430. Specifically, when the selection signal SELECT is at an L level, the relay 430 is switched on and the relay 432 is switched off. When the selection signal SELECT is at an H level, the relay 430 is switched off and the relay 432 is switched on.

[0089] A voltage sensor 440 detects the voltage of the solar battery 50A connected to the terminals 410, and outputs the detected value of the voltage to the CCID 420. The voltage sensor 442 detects the voltage of the electric power supply system 50B connected to the terminals 412, and outputs the detected value of the voltage to the CCID 420. Incidentally, when the solar battery 50A is not connected to the terminals 410, the detected value from the voltage sensor 440 is zero, which makes it possible to detect that the solar battery 50A is not connected to the adaptor 40C. Likewise, when the electric power supply system 50B is not connected to the terminals 412, the detected value from the voltage sensor 442 is zero, which makes it possible to detect that the electric power supply system 50B is not connected to the adaptor 40C.

[0090] FIG. 15 is a diagram showing an example of a relation between the states of connection of external electric power sources and the frequency of the pilot signal CPLT. Referring to FIG. 15, when only the solar battery 50A is connected to the adaptor 40C, the CCID 420 generates a pilot signal CPLT of a frequency fl . Besides, when only the electric power supply system SOB is connected to the adaptor 40C, the CCID 420 generates a pilot signal CPLT of a frequency f2. Furthermore, when both the solar battery 50A and the electric power supply system 50B are connected to the adaptor 40C, the CCID 420 generates a pilot signal CPLT in which the frequencies fl and f2 appear alternately with each other at predetermined intervals. In addition, when there are more than three types of external electric power sources, more than three frequencies sequence at predetermined intervals.

[0091] FIG. 16 is a function block diagram of a CPU that is included in the charging ECU 18A in the second embodiment. Referring to FIG. 16, the CPU of the charging ECU 18A includes an identification portion 202A, a charging control portion 204A, and a selection portion 206.

[0092] The identification portion 202A identifies the type of the external electric power source 50 on the basis of the frequency of the pilot signal CPLT, and outputs the identified type thereof to the charging control portion 204A and the selection portion 206. Concretely, the identification portion 202 A identifies the external electric power source as being the solar battery 50A when the frequency of the pilot signal CPLT is fl, and identifies the external electric power source as being the electric power supply system 50B when the frequency of the pilot signal CPLT is f2. When the frequency of the pilot signal CPLT alternates between fl and f2, the identification portion 202A determines that both the solar battery 50A and the electric power supply system 50B are connected as external electric power sources to the adaptor 40C, and notifies it to the selection portion 206.

[0093] When the external electric power source connected to the adaptor 40C is identified as being the solar battery 50A, the selection portion 206 sets the level of the selection signal SELECT to be output to the adaptor 40C to the L level. When the external electric power source connected to the adaptor 40C is identified as being the electric power supply system 50B, the selection portion 206 sets the level of the selection signal SELECT to the H level. When the solar battery 50A and the electric power supply system 50B are both connected as external electric power sources to the adaptor 40C, the selection portion 206 selects one of the solar battery 50A and the electric power supply system 50B by a method described later, and determines the logic level of the selection signal SELECT on the basis of a result of the selection.

[0094] The charging control portion 204A, on the basis of the detected values of the voltage V and the current I, generates a signal PWC for controlling the charger 16 according to the external electric power source that is shown by the selection signal SELECT from the selection portion 206.

[0095] FIG. 17 is a flowchart illustrating a processing procedure of the charging ECU regarding selection of an external electric power source. Referring to FIG. 17, the charging ECU 18A receives the pilot signal CPLT, and detects the frequency of the pilot signal CPLT (step S I 10). Next, the charging ECU 18A determines whether or not the number of the external electric power sources connected to the adaptor 40C is plural, on the basis of the frequency of the detected pilot signal CPLT (step S 120). Concretely, if the frequency of the pilot signal CPLT changes at predetermined intervals, it is determined that both the solar battery 50A and the electric power supply system 50B are connected to the adaptor 40C.

[0096] If in step S I 20 it is determined that the number of the external electric power sources is plural (YES in step S 120), the charging ECU 18A then determines whether or not the voltage V_pv (average value) of the solar battery 50A is higher than an operating voltage's lower limit value Va (step S 130). Incidentally, the voltage V_pv (average value) of the solar battery 50A is included in the voltage information from the adaptor 40C.

[0097] If in step S 130 it is determined that the voltage V_pv is higher than the operating voltage's lower limit value Va (YES in step S 130), the charging ECU 18A sets the charging mode to the solar charging mode (step S 140), and sets the level of the selection signal SELECT to be output to the adaptor 40C to the L level (step S 150).

[0098] If in step S I 30 it is determined that the voltage V_pv is lower than or equal to the operating voltage's lower limit value Va (NO in step S I 30), the charging ECU 18A determines whether or not the voltage V_ac (effective value) of the electric power supply system 50B is higher than an operating voltage's lower limit value Vb and is lower than an operating voltage's upper limit value Vc (step S 160). Besides, the voltage V_ac (effective value) of the electric power supply system 50B is included in the voltage information from the adaptor 40C.

[0099] Than, if it is determined that the voltage V_ac is higher than the operating voltage's lower limit value Vb and lower than the operating voltage's upper limit value Vc (YES in step S 160), the charging ECU 18A sets the charging mode to the system charging mode (step S I 70), and sets the selection signal SELECT to the H level (step S 180). Incidentally, if in step S 160 it is determined that the voltage V_ac is lower than or equal to the operating voltage's lower limit value Vb, or is higher than or equal to the operating voltage's upper limit value Vc (NO in step S I 60), the charging ECU 18A stops the charging of the electricity storage device 12 performed by the charger 16 (step S 190).

[0100] If in step S I 20 it is determined that the number of external electric power sources is not plural (NO in step S 120), the charging ECU 18A determines whether or not the frequency of the pilot signal CPLT is fl (step S200). Then, if it is determined that the frequency of the pilot signal CPLT is fl (YES in step S200), the charging ECU 18A sets the charging mode to the solar charging mode (step S210), and sets the selection signal SELECT to the L level (step S220).

[0101] On the other hand, if in step S200 it is determined that the frequency of the pilot signal CPLT is not fl (NO in step S200), the charging ECU 18A sets the charging mode to the system charging mode (step S230), and sets the selection signal SELECT to the H level (step S240).

[0102] Incidentally, although, in the foregoing description, the external electric power source to be used for the charging is selected on the basis of the voltage of the external electric power source, it is also permissible to select the external electric power source for use on the basis of an environmental index such as the amount of carbon dioxide generated at the time of electricity generation, or the like.

[0103] Besides, although, in the foregoing description, the external electric power source to be used is selected on the vehicle 10A side and a result of the selection is notified to the adaptor 40C, it is also permissible to provide the adaptor 40C with a function of selecting the external electric power source to be used, so that a result of the selection of the external electric power source to be used will be notified from the adaptor 40C to the vehicle 10A.

[0104] As can be understood from the foregoing description, in the second embodiment, since one of a plurality of external electric power sources is selected and the charger 16 is controlled according to the selected external electric power source, there is no need to construct a charging circuit separately for each of the external electric power sources nor to provide a charger separately for each source. Therefore, by the second embodiment, too, a vehicle charging system that supports a plurality of external electric power sources can be realized in a small size at low cost.

[0105] Although the solar battery and the electric power supply system are described above as examples of external electric power sources in conjunction with the foregoing embodiments, the external electric power sources for use are not limited to those sources, but may also include an aerogeneration apparatus, a direct-current electric power supply system, etc.

[0106] Besides, although, in the foregoing description, each of the adaptors 40 and 40A to 40C is provided on the charging cable 30, none of the adaptors 40 are 40A to 40C needs to be integrated with the charging cable 30.^'

[0107] Besides, in the first embodiment, the pilot signal CPLT is used to notify the type of the external electric power source 50 from the adaptor 40 to the vehicle 10, and in the second embodiment, the pilot signal CPLT is used to notify the states of connection of the external electric power sources 50-1 and 50-2 from the adaptor 40C to the vehicle 10A. However, instead of using the pilot signal CPLT, a separate signal line may be provided for such notification. Furthermore, the pilot signal CPLT may also be substituted with electric power line communication (PLC).

[0108] Additionally, the control pilot circuit 122 may correspond to a "signal generation circuit" in the invention, and the relays 430 and 432 may correspond to a "switching portion" in the invention.

[0109] While the invention has been described with reference to example embodiments thereof, it is to be understood that the invention is not restricted to the particulars of the described embodiments. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the disclosed invention are shown in various example combinations and configurations, other combinations and configurations, including more, less or only a single element, are also within the scope of the appended claims.

Claims

1. A vehicle charging system for charging an electricity storage device mounted in a vehicle from an external electric power source, the vehicle charging system including: a charger that converts voltage of electric power supplied from the external electric power source and charges the electricity storage device with the electric power converted in voltage; a control portion for controlling voltage conversion performed by the charger; and an identification portion for identifying a type of the external electric power source,

the vehicle charging system being characterized in that

the control portion controls the voltage conversion of the charger according to the type of the external electric power source identified by the identification portion.

2. The vehicle charging system according to claim 1, wherein the control portion controls the voltage conversion of the charger based on an ampacity, a voltage and a current of the external electric power source that correspond to the type of the external electric power source identified by the identification portion.

3. The vehicle charging system according to claim 1 or 2, further comprising a signal generation circuit which generates a control signal that is modulated in pulse width according to magnitude of the current that is suppliable from the external electric power source to the vehicle, and which sends the control signal to the vehicle,

wherein the signal generation circuit changes frequency of the control signal according to the type of the external electric power source, and

wherein the identification portion identifies the type of the external electric power source based on the frequency of the control signal from the signal generation circuit.

4. The vehicle charging system according to claim 3, wherein:

the external electric power source includes a plurality of electric power sources; the signal generation circuit generates the frequency of the control signal according to the type of the electric power connected to the charger; and

when more than one of the plurality of electric power sources are connected to the charger, the signal generation circuit generates the control signal in which frequencies commensurate with the types of the electric power sources sequence at a predetermined interval.

5. The vehicle charging system according to claim 3, wherein the signal generation circuit changes a duty ratio of the frequency of the control signal according to a limit of charging current commensurate with the type of the external electric power source.

6. The vehicle charging system according to any one of claims 1 to 5, wherein: the external electric power source includes a plurality of electric power sources; the vehicle charging system further includes a switching portion provided between the charger and the plurality of electric power sources, and a selection portion that selects an electric power source among the plurality of electric power sources; and the switching portion electrically connects the electric power source selected by the selection portion to the charger, and electrically disconnects the electric power source that is not selected by the selection portion from the charger.

7. The vehicle charging system according to claim 6, wherein:

the plurality of electric power sources include an electric power supply system, and an electricity generation apparatus that is provided outside the vehicle; and

the selection portion selects the electricity generation apparatus when the voltage of the electricity generation apparatus is higher than a predetermined voltage, and selects the electric power supply system when the voltage of the electricity generation apparatus is lower than or equal to the predetermined voltage and the voltage of the electric power supply system is within a predetermined range.

8. The vehicle charging system according to claim 7, wherein the control portion stops charging of the electricity storage device when the voltage of the electricity generation apparatus is lower than or equal to the predetermined voltage and the voltage of the electric power supply system is outside the predetermined range.

9. The vehicle charging system according to claim 7 or 8, wherein the electricity generation apparatus includes a solar cell.

10. The vehicle charging system according to any one of claims 1 to 6, wherein: the external electric power source includes a plurality of electric power sources; and

the plurality of electric power sources include an electric power supply system, and an electricity generation apparatus that is provided outside the vehicle.

11. An electric vehicle including: an electricity storage device, an electric motor that receives electric power from the electricity storage device and that generates vehicle driving force, a charger that converts voltage of the electric power supplied from an external electric power source that charges the electricity storage device with the electric power converted in voltage, and a control device for controlling the charger,

the electric vehicle characterized in that

the control device includes: an identification portion for identifying a type of the external electric power source; and a charging control portion that controls the charger according to the type of the external electric power source identified by the identification portion, when the electricity storage device is charged from the external electric power source.

12. The electric vehicle according to claim 11, wherein the control device controls voltage conversion of the charger based on an ampacity, a voltage and a current of the external electric power source that correspond to the type of the external electric power source identified by the identification portion.

13. The electric vehicle according to claim 11 or 12, wherein:

a signal generation circuit which generates a control signal that is modulated in pulse width according to magnitude of the current that is suppliable from the external electric power source to the electric vehicle, and which sends the control signal to the electric vehicle is provided outside the electric vehicle;

the signal generation circuit changes frequency of the control signal according to the type of the external electric power source; and

the identification portion identifies the type of the external electric power source based on the frequency of the control signal from the signal generation circuit.

14. The electric vehicle according to claim 13, wherein: the external electric power source includes a plurality of electric power sources; the signal generation circuit generates the frequency of the control signal according to the type of the electric power source connected to the charger; and

15. The electric vehicle according to claim 13, wherein the signal generation circuit changes a duty ratio of the frequency of the control signal according to a limit of charging current commensurate with the type of the external electric power source.

16. The electric vehicle according to claim any one of claims 11 to 15, wherein: the external electric power source includes a plurality of electric power sources; a switching portion provided between the charger and the plurality of electric power sources is provided outside the electric vehicle;

the control device further includes a selection portion that selects an electric power source among the plurality of electric power sources; and

the switching portion electrically connects the electric power source selected by the selection portion to the charger, and electrically disconnects the electric power source that is not selected by the selection portion from the charger.

17. The electric vehicle according to claim 16, wherein:

the plurality of electric power sources include an electric power supply system, and an electricity generation apparatus that is provided outside the electric vehicle; and the selection portion selects the electricity generation apparatus when the voltage of the electricity generation apparatus is higher than a predetermined voltage, and selects the electric power supply system when the voltage of the electricity generation apparatus is lower than or equal to the predetermined voltage and the voltage of the electric power supply system is within a predetermined range.

18. The electric vehicle according to claim 17, wherein the control portion stops charging of the electricity storage device when the voltage of the electricity generation apparatus is lower than or equal to the predetermined voltage and the voltage of the electric power supply system is outside the predetermined range.

19. The electric vehicle according to claim 17 or 18, wherein the electricity generation apparatus includes a solar cell.

20. The electric vehicle according to any one of claims 11 to 16, wherein:

the external electric power source includes a plurality of electric power sources; and

the plurality of electric power sources include an electric power supply system, and an electricity generation apparatus that is provided outside the electric vehicle.