BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The invention relates to an electromotive vehicle and, more particularly, to an electric system of an electromotive vehicle equipped with an electrical storage device that may be charged by a power supply outside the vehicle.

2. Description of Related Art

[0002] In an electromotive vehicle, such as an electric vehicle and a hybrid vehicle, that drives a vehicle drive motor with electric power supplied from an electrical storage device, typically, a secondary battery, there has been suggested a configuration that a charging device is charged by a power supply outside the vehicle (hereinafter, also simply referred to as "external power supply"). Note that, hereinafter, charging the electrical storage device by the external power supply is also referred to as "external charging",

[0003] Japanese Patent Application Publication No. 2009-225587 (JP-A-2009-225587) describes the configuration of an electric system of an externally chargeable electromotive vehicle. In this electric system, a charging path for externally charging a main battery is provided independently of a current-carrying path between a motor generator for generating vehicle driving force and the main battery, the current-carrying path being formed by turning on a main relay. Furthermore, an auxiliary load system including an auxiliary battery is configured to be supplied with electric power through a power supply line different from the current-carrying path so as to be able to operate even when the main relay is turned off.

[0004] By so doing, during external charging, the main relay that consumes a large amount of electric power may be turned off, and the operating electric power of the auxiliary load system may be supplied.

[0005] Owing to development of the externally chargeable electromotive vehicle as described in JP-A-2009-225587, electromotive vehicles mixedly include a vehicle model having no external charging mechanism and a vehicle model having an external charging mechanism. Here, in the vehicle model having an external charging mechanism, it is necessary to ensure operations of auxiliaries during external charging, which is not assumed in the vehicle model having no external charging mechanism.

[0006] However, it is desirable not to significantly change the arrangement of devices, including an auxiliary system, between vehicle models in terms of design versatility.

[0007] Here, the electric system of the electromotive vehicle described in JP-A-2009-225587 illustrates a system configuration for achieving both improvement in the efficiency of external charging and ensuring the operation of the auxiliary system; however, JP-A-2009-225587 does not refer to the arrangement layout of components of the electrical system at all.

SUMMARY OF THE INVENTION

[0008] The invention provides an appropriate configuration and arrangement layout of an externally chargeable electromotive vehicle and its electric system in terms of operation during external charging and design versatility.

[0009] An aspect of the invention provides an electromotive vehicle equipped with a motor that generates vehicle driving power. The electromotive vehicle includes: an electrical storage device; an external charging mechanism; a first power converter; first and second power supply lines, first and second switches, a voltage converter, and an air conditioner that includes a second power converter. The electrical storage device stores electric power input to or output from the motor. The external charging mechanism, when the vehicle is in an external charging mode for charging the electrical storage device by an external power supply, converts electric power supplied from the external power supply to charging electric power used for charging the electrical storage device and is used to supply the charging electric power to the electrical storage device. The first power converter is mounted in a region of the vehicle before the electrical storage device in a front-back direction of the vehicle, and is used to convert electric power between the electrical storage device and the motor when the vehicle is in a vehicle running mode. The first power supply line is used to connect the electrical storage device to the first power converter. The first switch is connected between the first power supply line and the electrical storage device, wherein the first switch is turned on when the vehicle is in the vehicle running mode and is turned off when the vehicle is in the external charging mode. The voltage converter is used to step down output voltage of the electrical storage device to driving voltage for driving auxiliaries. The second power supply line is used to connect the electrical storage device to the voltage converter. The second switch is connected to the electrical storage device in parallel with the first switch, and is connected between the second power supply line and the electrical storage device. The air conditioner includes a second power converter that is electrically connected to the second power supply line. The external charging mechanism is arranged closer to the electrical storage device than the first power converter, and the voltage converter and the air conditioner are arranged closer to the first power converter than the electrical storage device.

[0010] In addition, the electromotive vehicle according to the above aspect may further include a first control unit that operates when the vehicle is in both the vehicle running mode and the external charging mode, and that is used to monitor the electrical storage device; and a second control unit that is used to control running of the electromotive vehicle, wherein the second control unit may operate when the vehicle is in the vehicle running mode, and may be stopped when the vehicle is in the external charging mode, and the voltage converter, the second power converter and the second switch may be controlled by the first control unit.

[0011] In addition, in the electromotive vehicle according to the above aspect, the external charging mechanism, may include a charger that is used to convert electric power supplied from the external power supply to charging electric power for charging the electrical storage device and a third power supply line that is used to transmit output electric power of the charger, the third power supply line may be connected to the second power supply line without passing through the second.switch, and the second switch may tum on when the vehicle is in both the vehicle running mode and the external charging mode.

[0012] In addition, in the electromotive vehicle according to the above aspect, in the case where the electrical storage device is not charged arid the external power supply and the external charging mechanism are electrically connected to each other, when a power position at which the air conditioner is activated is selected, the second switch may be turned off and the charger may be activated.

[0013] In addition, in the electromotive vehicle according to the above aspect, the external charging mechanism may include a charger that is used to convert electric power supplied from the external power supply to charging electric power for charging the electrical storage device, a third power supply line that is used to transmit output electric power of the charger and a third control unit that is used to control charging of the electrical storage device by the external power supply, the electromotive vehicle may further include a third switch that is connected between the third power supply line and the electrical storage device and that is turned on or off by the third control unit, and the third switch may be turned off when the vehicle is in the vehicle running mode, and may be turned on when the vehicle is in the external charging mode.

[0014] In addition, in the electromotive vehicle according to the above aspect, the air conditioner may be configured to be activated at a power position at which part of the auxiliaries are operated.

[0015] According to the above aspect of the invention, it is possible to provide an appropriate configuration and arrangement layout of the electric system of an externally chargeable electromotive vehicle in terms of operation during external charging and design versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

FIG 1 is a block diagram that shows the configuration of a hybrid vehicle that is a typical example of an electromotive vehicle according to a first embodiment of the invention;

FIG. 2 is a block diagram that shows the configuration of a hybrid vehicle having no external charging mechanism, which is shown as a comparative example;

FIG 3 is a table that shows controls in operating states of the hybrid vehicle shown in FIG 2;

FIG 4 is a table that shows controls in operating states of the hybrid vehicle shown in FIG 1;

FIG 5 is a block diagram that shows the configuration of a hybrid vehicle that is shown as a typical example of an electromotive vehicle according to an alternative embodiment to the first embodiment of the invention;

FIG. 6 is a table that shows controls in operating states of the hybrid vehicle, shown in FIG 5;

FIG 7 is a block diagram that shows the configuration of a hybrid vehicle that is a typical example of an electromotive vehicle according to a second embodiment of the invention; and

FIG. 8 is a block diagram that shows the configuration of a hybrid vehicle that is shown as a typical example of an electromotive vehicle according to an alternative embodiment to the second embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0017] Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. Note that like reference numerals denote the same or corresponding components in the drawings and the description thereof will not be repeated basically.

[0018] FIG 1 is a block diagram that shows the configuration of a hybrid vehicle 5 that is a typical example of an electromotive vehicle according to a first embodiment of the invention. FIG. 1 mainly shows the configuration and arrangement layout of the electric system of the hybrid vehicle 5.

[0019] As shown in FIG. 1, the hybrid vehicle 5 according to the first embodiment includes a main battery 10, a power control unit (PCU) 20, an engine 30, motor generators MG1 and MG2, a power transmission gear 40, a drive shaft 45, front wheels 50a that are drive wheels, and rear wheels 50b.

[0020] The main battery 10 corresponds to an "electrical storage device", and is typically formed of a secondary battery, such as a lithium ion battery and a nickel metal hydride battery. For example, the output voltage of the main battery 10 is about 200 V. Alternatively, the electrical storage device may be, for example, formed of an electric double layer capacitor or may be formed of a combination of a secondary battery and a capacitor.

[0021] The PCU 20 includes inverters 21 and 22. and a converter 23. The inverters 21 and 22 and the converter 23 serve as a "first power converter" that is used to convert electric power stored in the main battery 10 to electric power for driving the motor generators MG1 and MG2. The motor generators MG1 and MG2 each are formed of a permanent magnet-type three-phase synchronous electric motor.

[0022] The power transmission gear 40 couples the output shafts of the motor generators MG1 and MG2 and engine 30 to the drive shaft 45. The power transmission gear 40 is formed of a reduction gear and a power split mechanism. As a result, the output of the engine 30 and/or the output of the motor generator MG2 are transmitted to the drive wheels (for example, front wheels 50a) via the drive shaft 45 to thereby cause the hybrid vehicle 5 to run. That is, the engine 30 and the motor generators MG1 and MG2 are operated in cooperation with one another to generate a vehicle driving force required of the hybrid vehicle 5.

[0023] Note .that the output of the engine 30 is transmitted to the motor generator MG1 to make it possible to cause the motor generator MG1 to generate electric power. Alternatively, the output of the motor generator MG1 is used to make it possible to start the engine 30.

[0024] The motor generator MG2 is able to generate electric power using the rotational force of the drive wheels (for example, front wheels 50a) during regenerative braking of the hybrid vehicle 5. Then, the generated electric power is converted to charging electric power for charging the main battery 10 by the PCU 20.

[0025] Note that the configuration of the drive train of the hybrid vehicle is not limited to the configuration illustrated in FIG. 1. For example, a single motor generator and the engine may be used as driving force sources to constitute the drive train.

[0026] The hybrid vehicle 5 is equipped with a plurality of electronic control units (ECUs). Each ECU is formed to incorporate a central processing unit (CPU) and a memory (both are not shown). Each ECU is configured to execute operations using values detected by sensors on the basis of maps and programs stored in the memory. Note that each ECU or at least part of each ECU may be configured to execute predetermined numerical/logical operations by hardware, such as an electronic circuit.

[0027] A battery monitoring unit 12 monitors the state of the main battery 10 on the basis of the outputs from sensors provided for the main battery 10. The battery monitoring unit 12 is, for example, incorporated in a battery pack 15. Then, the battery monitoring unit 12 transmits the state values (voltage, current, temperature, and the like) of the main battery 10 based on the sensor outputs to an HV-ECU 80 (described later). In addition, when an abnormality of the main battery 10 has been detected, a signal that indicates that the abnormality has been detected is transmitted from the battery monitoring unit 12 to the HV-ECU 80.

[0028] The HV-ECU 80 controls the overall operation of the hybrid vehicle 5.

Typically, the HV-ECU 80 calculates a driving force or braking force required of the hybrid vehicle 5 as a whole on the basis of a vehicle state, driver's operation (accelerator operation or brake operation), and the like, and generates control instructions for generating the calculated driving force or braking force. [0029] At this time, the HV-ECU 80 estimates the state of charge (SOC) of the main battery 10 and sets the upper limits of charging electric power and discharging electric power for the main battery 10 on the basis of the state values of the main battery 10 from the battery monitoring unit 12. Then, the HV-ECU 80 determines the distribution of output among the engine 30 and the motor generators MGl and MG2 with limitations so as not to excessively discharge or excessively charge the main battery 10 in consideration of the SOC of the main battery 10 and the upper limits of charging and discharging electric powers.

[0030] An engine ECU 35 controls the output of the engine 30 in accordance with the control instructions from the HV-ECU 80. Specifically, fuel injection, ignition timing, valve timing, and the like, in the engine 30 are controlled. An MG-ECU 81 controls the outputs of the motor generators MGl and MG2 in accordance with control instructions from the HV-ECU 80. Specifically, the inverters 21 and 22 are controlled so that the output torques of the motor generators MGl and MG2 coincide with torque command values. In addition, the converter 23 is controlled so that the direct-current voltage VH of a power supply line 154p coincides with a voltage command value.

[0031] An electronically controlled brake unit (ECB) 82 controls regenerative braking force generated by the motor generator MG2 and braking force generated by a hydraulic brake (not shown) in cooperation with each other during braking of the vehicle to thereby ensure braking force required of the hybrid vehicle 5 as a whole.

[0032] Next, the configuration of the power supply system of the hybrid vehicle 5 will be described in detail. The positive electrode terminal of the main battery 10 is connected to a power supply line 153p via a system main relay SMRl, and the negative electrode terminal of the main battery 10 is connected to a ground line 153g via a system main relay SMR2 or SMR3. The system main relays SMRl to SMR3 correspond to a "first switch", and the power supply line 153p corresponds to a "first power supply line".

[0033] Hereinafter, the system main relays SMRl to SMR3 are also collectively simply referred to as "SMR". When the SMR is turned on, the SMRl and the SMR2 or SMR3 are turned on. The SMR3 is connected to a resistive element for suppressing inrush current at start-up. Therefore, when a predetermined period of time elapses from start-up, the SMR2 is turned on instead of the SMR3.

[0034] When the SMR is on, the voltage of the main battery 10 is applied to the components of the PCU 20, and the like, via the power supply line 153p. On the other hand, when the SMR is off, all the system main relays SMR1 to SMR3 are off, and the main battery 10 is electrically isolated from the power supply line 153p and the PCU 20.

[0035] Note that the relays, such as the system main relays SMR1 to SMR3, used in the present embodiment each are typically formed of an electromagnetic relay that closes (turns on) when exciting current is supplied from an exciting circuit (not shown) and, on the other hand, opens (turns off) when no exciting current is supplied.

However, as long as a switch that is able to control conduction (on)/interruption (off) of the current-carrying path, ¾ny circuit element may be used as each relay. Each of the system main relays SMR1 to SMR3 is turned on or off by the HV-ECU 80.

[0036] The converter 23 is configured to bidirectionally convert direct-current voltage between the direct-current voltage VL of the power supply line 153p and the direct-current voltage VH of the power supply line 154p. The direct-current voltage VL corresponds to the output voltage of the main battery 10. Any power conversion circuit having a direct-current voltage conversion function may be employed as the converter 23.

Note that the PCU 20 (first power converter) may be formed without arrangement of the converter 23. In this case, the output voltage of the main battery 10 is directly the direct-current-side voltage of each of the inverters 21 and 22.

[0037] Each of the inverters 21 and 22 is, for example, formed of a general three-phase inverter. For example, each of the inverters 21 and 22 is formed so that an upper arm element and a lower arm element are arranged in each phase and the connection point of the upper and lower arm elements of each phase is connected to a stator coil winding of a corresponding one of the phases of the motor generator MGl or

MG2.

[0038] When the hybrid vehicle 5 is running, the inverters 21 and 22 each convert the direct-current jyoltage of the power supply line 154p to three-phase alternating-current voltage in such a manner that the switching elements are turned on or off by the MG-ECU 81 and then supply the three-phase alternating-current voltage to the corresponding one of the motor generators MG1 and MG2. Alternatively, when the hybrid vehicle 5 is operated to perform regenerative braking, the switching elements of the inverter 22 are turned on or off by the MG-ECU 81 so as to convert the alternating-current voltage from the motor generator MG2 to direct-current voltage and then outputs the direct-current voltage to the power supply line 154p.

[0039] The hybrid vehicle 5 further includes a DC-DC converter 60, an auxiliary battery 70, an air conditioner 90, a power supply line 155p and a ground line 155g as an auxiliary system. The air conditioner 90 includes an inverter 92 for driving a compressor (not shown) (hereinafter, also referred to as "A/C inverter"). The A/C inverter 92 corresponds to a "second power converter", and the power supply line 155p corresponds to a "second power supply line". When the air conditioner 90 is driven, the A/C inverter 92 operates in accordance with control instructions from the HV-ECU 80.

[0040] The power supply line 153p and the ground line 153g are respectively connected to the positive electrode terminal and negative electrode terminal of the main battery 10 via auxiliary relays RL1 and RL2. Note that, in the following description, RL1 and RL2 are also simply collectively referred to as "RL". The auxiliary relay RL corresponds to a "second switch". The auxiliary relay RL is turned on or off by the HV-ECU 80.

[0041] When the RL is on, the voltage of the main battery 10 is transmitted to the power supply line 155p, On the other hand, when the RL is off, the main battery 10 is electrically isolated from the power supply line 155p.

[0042] The auxiliary relay RL is connected to the main battery 10 in parallel with the SMR. That is, the output voltage (direct-current voltage VL) of the main battery 10 is branched into a path that includes the SMR and the power supply line 153p and a path that includes the auxiliary relay RL and the power supply line 155p, and the branched output voltages are respectively transmitted to the PCU 20 and the auxiliary system. [0043] The DC-DC converter 60 steps down the voltage VL of the power supply line 155p (corresponding to the output voltage of the main battery 10) to direct-current voltage Vi having a level of the output voltage of the auxiliary battery 70. The DC-DC converter 60 is typically a switching regulator that includes a semiconductor switching element (not shown), and may use a selected circuit configuration. The DC-DC converter 60 operates in accordance with control instructions from the HV-ECU 80.

[0044] The auxiliary battery 70 is, for example, formed of a lead-acid battery, and is charged with the output voltage of the DC-DC converter 60. The voltage of the auxiliary battery 70 is lower than the output voltage of the main battery 10, and is, for example, about 12 V.

[0045] Low-voltage auxiliary loads (not shown) are connected to the auxiliary battery 70. These auxiliary loads operate in response to user's operation to consume electric power. The auxiliary loads, for example, include an audio device, a navigation device, illumination devices (hazard lamp, interior lamp, head lamp, and the like), and the like. Furthermore, the low-voltage auxiliary loads include driving system auxiliaries that are directly used in vehicle running, such as an electric power steering mechanism, an electric oil pump and a compact motor for electronic control.

[0046] The hybrid vehicle 5 further includes a charging inlet 105, a charger 110, a power supply line 152p and a ground line 152g as an "external charging mechanism" for externally charging the main battery 10. The power supply line 152p corresponds to a "third power supply line".

[0047] The inlet 105 is connected to an external power supply 400 by a charging cable 410. The charging cable 410 includes an AC plug 412, a charging circuit interrupt device (CCID) box 414 and a connector 416. The AC plug 412 is used to connect with the external power supply 400. The connector 416 is used to connect with the inlet 105. Generally, the external power supply 400 is formed of a commercial alternating-current power supply.

[0048] The CCID box 414 includes a relay and a signal generating circuit (both are not shown). The signal generating circuit outputs signals that indicate the connection state of the charging cable 410 and external power supply 400 and the current capacity of the charging cable 410 to the hybrid vehicle 5. In addition, owing to the relay of the CCID box 414, even when the external power supply 400 and the inlet 105 are connected to each other by the charging cable 410, an external charging path may be interrupted.

[0049] The charger 110 converts alternating-current voltage transmitted from the external power supply 400 to the inlet 105 to direct-current voltage VL for charging the main battery 10. The converted direct-current voltage is output to between the power supply line 152p and the ground line 152g.

[0050] The PLG-ECU 115 controls the operation of the charger 110 during external charging. As a result, the charger 110 charges the main battery 10 through feedback control over output voltage and/or output current in accordance with control instructions from the PLG-ECU 115 for controlling external charging. The charging instructions are set on the basis of the state, such as SOC and temperature, of the main battery 10, transmitted from the HV-ECU 80.

[0051] Note that, instead of the configuration shown in FIG 1, a configuration that supplies electric power by electromagnetically coupling the external power supply 400 to the electromotive vehicle 100 in a noncontact manner may be applied. Specifically, it is applicable that a primary coil is provided at an external power supply side, a secondary coil is provided at a vehicle side and the mutual inductance between the primary coil and the secondary coil is used to supply electric power from the external power supply 400 to the electromotive vehicle 100. Even when such external charging is performed, the configuration downstream of the charger 110, which converts electric power supplied from the external power supply 400, may be commonalized.

[0052] The power supply line 152p and the ground line 152g are electrically connected to the power supply line 155p and ground line 155g of the auxiliary system without passing through the auxiliary relays RL1 and RL2. Thus, even when the auxiliary relay RL is not turned on, the direct-current voltage YL based on electric power supplied from the _, external power supply 400 may be _^ supplied to the power supply line 155p of the auxiliary system. On the other hand, in order to supply the direct-current voltage VL based on electric power from the external power supply 400 to the main battery 10, it is necessary to turn on the auxiliary relay RL.

[0053] Here, the configuration of a hybrid vehicle 5# that has no external charging mechanism will be described as a comparative example.

[0054] As shown in FIG 2, the hybrid vehicle 5# differs from the hybrid vehicle 5 shown in FIG. 1 in that no external charging mechanism for externally charging the main battery 10 is provided, that is, the inlet 105, the charger 110, the power supply line 152p and the ground line 152g are not provided.

[0055] Furthermore, in the hybrid vehicle 5#, the power supply lines 155p and

155g of the auxiliary system shown in FIG. 1 are not arranged. Therefore, the DC-DC converter 60 and the A/C inverter 92 are connected to the power supply lines 153p and I53g that are connected to the main battery 10 via the S R. Thus, the auxiliary relays RL1 and RL2 are not arranged.

[0056] As a result, in order to drive the air conditioner 90 by operating the A/C inverter 92, it is necessary to turn on the SMR. In addition, the DC-DC converter 60 is also controlled so as to operate when the SMR is on. Therefore, the DC-DC converter 60 is arranged in proximity to the PCU 20 or arranged inside the PCU 20 as shown in the drawing.

[0057] In addition, the battery pack 15 is arranged in a vehicle rear region (for example, a region behind a rear seat (not shown)). The PCU 20 is arranged in a vehicle front region in proximity to the motor generators MGl and MG2 that are coupled to the engine 30 via the power transmission gear 40. The A/C inverter 92 is also arranged in proximity to the PCU 20 in order to branch off the direct-current voltage VL from the PCU 20 by a bus bar. That is, the DC-DC converter 60 and the A/C inverter 92 (air conditioner 90) are arranged closer to the PCU 20 than the main battery 10.

[0058] The other configuration of the hybrid vehicle 5# shown in FIG. 2 is similar to the hybrid vehicle 5 shown in FIG. 1, so the detailed description will not be repeated. [0059] FIG. 3 is a tabic that shows controls in operating states of the hybrid vehicle 5# shown in FIG 2. IG and ACC in FIG 3 are power positions selected by user's operation. Normally, when IG is set to an on state by user's operation, ACC is also set to an on state.

[0060] As shown in FIG 3, the hybrid vehicle 5# enters a drivable state (vehicle . running mode) when an operation to request for system start-up (for example, an operation to push a power switch while depressing a brake pedal) in a state where IG is set to an on state. In the vehicle running mode, the SMR is turned on to connect the main battery 10 to the PCU 20 via the power supply line 153p. By so doing, hybrid running using the outputs of the motor generators MG1 and MG2 is enabled. In the vehicle running mode, the A/C inverter 92 may also be driven by receiving the direct-current voltage VL transmitted through the power supply line 153p. In addition, when IG is set to an on state, all the auxiliary loads, including the driving system auxiliaries, may be driven. The DC-DC converter 60 steps down the direct-current voltage VL transmitted through the power supply line 153p to supply charging voltage for charging the auxiliary battery 70 (or power supply voltage of the low-voltage auxiliary loads).

[0061] In the hybrid vehicle 5#, when the vehicle is not running, (i) ACC is set to an on state to make it possible to drive part of auxiliaries, such as the audio device and the navigation device, and (ii) IG is set to an on state to make it possible to drive all the low-voltage auxiliaries, including the driving system auxiliaries. However, in the states of the above (i) and (ii), the SMR is maintained at an off state, so the direct-current voltage VL supplied from the main battery 10 is not supplied to the power supply line 153p. Thus, the A/C inverter 92 cannot start up. That is, when the air conditioner 90 (A/C inverter 92) is started up, it is necessary to place the vehicle in the drivable state (vehicle running mode) by an operation to request for system start-up in order to turn on the SMR. Furthermore, the DC-DC converter 60 is also stopped, so electric power for driving the auxiliary loads is provided by the auxiliary battery .70.

[0062] On the other hand, (iii) a pre-air-conditioning mode may be provided for 11 002399

15

the hybrid vehicle 5# at the time when the vehicle is not running in order to drive the air conditioner 90 from the outside of the vehicle as a special power mode other than the above (i) or (ii). For example, the pre-air-conditioning mode is started by operating a remote control key for the hybrid vehicle 5# of which all the doors are closed.

[0063] In the pre-air-conditioning mode, IG is set to an on state and the SMR is turned on automatically, so the air conditioner 90 (A/C inverter 92) is driven to make it possible to adjust the temperature inside a vehicle cabin. Note that, in terms of a protection against theft, or the like, it is applicable that, when any operation, such as opening the door, is performed on the hybrid vehicle 5#, the pre-air-conditioning mode is automatically cancelled to turn off the SMR and set IG to an off state.

[0064] In the hybrid vehicle 5 shown in FIG 1, having an external charging mechanism, when the vehicle is not running, there is an "external charging mode" that is not assumed in the hybrid vehicle 5# shown in FIG. 2. Then, in the external charging mode as well, it is necessary to drive the auxiliary system, including the air conditioner 90, in response to user's operation.

[0065] Therefore, the hybrid vehicle 5 shown in FIG 1 is controlled in the operating states as shown in FIG 4.

[0066] As shown in FIG 4, in the hybrid vehicle 5, IGP is provided as a power position in addition to IG and ACC. IGP is set to an on state at least during a period when the main battery 10 is being charged with electric power from the external power supply 400 by connecting the charging cable 410. Note that IG and IGP are exclusively set to an on state. That is, when IG is on, IGP is not shifted from an off state to an on state even when the charging cable 410 is connected. Similarly, when IGP is on, IG is not shifted from an off state to an on state even when the user operates an IG switch.

[0067] In the hybrid vehicle 5, when the vehicle is running (vehicle running mode), IGP is set to an off state, while IG is set to an on state. Resulting from the on state of IG ACC is automatically set to an on state. In the vehicle running mode, the SMR and the RL both are turned on. By so doing, the output voltage of the main battery 10 is transmitted to both the power supply lines 153p and 155p., As a result, hybrid running is enabled, and all the auxiliary system, including the low-voltage auxiliary loads and the air conditioner 90, may be driven.

[0068] The operation in a state where IGP is on (external charging mode) is classified into the case where only external charging of the main battery 10 is performed and the case where, during external charging, the auxiliary system (including the air conditioner 90) other than the driving system auxiliaries that are operable by setting IG to an on state is driven.

[0069] In the case where only external charging is performed, that is, in the case where the auxiliary system, including the air conditioner 90, is not driven, ACC is set to an off state and IG is set to an off state. In addition, the SMR is turned off, and the auxiliary relay RL is turned on for external charging.

[0070] Because the SMR is turned off, no voltage is applied to the PCU 20. In addition, the operation of the PCU 20 may also be stopped.

[0071] On the other hand, because the auxiliary relay RL is turned on, the output electric power (direct-current voltage VL), which is supplied from the charger 110 and originates in electric power supplied from the external power supply 400, charges the main battery 10 via the power supply line 152p and the auxiliary relay RL. The output electric power supplied from the charger 110 or the main battery 10 is supplied to the power supply line 155p; however, ACC is off, so the DC-DC converter 60 and the air conditioner 90 (A/C inverter 92) do not start up or operate.

[0072] In the case where the auxiliary system (including the air conditioner 90) other than the driving system auxiliaries is driven during external charging, ACC is set to an on state by user's operation. That is, in the hybrid vehicle 5, different from the hybrid vehicle 5# shown in FIG. 2, even when IG is off, ACC is set to an on state to make it possible to drive the air conditioner 90. In response to this, the HV-ECU 80 starts up the DC-DC converter 60 and the air conditioner 90 (A/C inverter 92). By so doing, the DC-DC converter 60 and the air conditioner 90 (A/C inverter 92) operate on electric power (direct-current voltage VL) supplied through the power supply line 155p. As a result, it is possible to drive the auxiliary system, including the air conditioner 90, during external charging.

[0073] During external charging, the HV-ECU 80 turns on or off the auxiliary relay RL in cooperation with the PLG-ECU 115. The HV-ECU 80 monitors the SOC of the main battery 10 during external charging. When the main battery 10 becomes a full charge state or when a prescribed charging time elapses, the auxiliary relay RL is turned off, and the charging path from the charger 110 to the main battery 10 is interrupted.

[0074] When the hybrid vehicle 5 is not running and is not charged, there are three modes, that is, (i) ACC is on, (ii) IG is on and (iii) pre-air-conditioning mode as in the case of FIG 3. As described above, in the hybrid vehicle 5, in the mode of (i) ACC is on, the air conditioner 90 may be driven in addition to part of auxiliaries, such as the audio device and the navigation device. Thus, the SMR is turned off, while the auxiliary relay RL is turned on.

[0075] In the mode of (ii) IG is on as well, the SMR is turned off, while the auxiliary relay RL is turned on to thereby make it possible to drive all the low-voltage auxiliaries including the driving system auxiliaries. In addition, in the (iii) pre-air-conditioning mode, different from the case shown in FIG. 3, ACC is set to an on state, while IG is set to an off state. This is because, in the hybrid vehicle 5, when ACC is on, the air conditioner 90 may be driven. In the pre-air-conditioning mode as well, the SMR is turned off, while the auxiliary relay RLis turned on.

[0076] In this way, when the hybrid vehicle 5 is not running and is not charged, in the case where the auxiliaries are driven, the SMR is turned off, while the auxiliary relay RL is turned on throughout the modes (i) to (iii). When the auxiliary relay RL is turned on, electric power supplied from the main battery 10 may be used to drive the auxiliaries including the air conditioner 90.

[0077] Note that, even when the vehicle is not running and is not charged, but when electric power may be supplied from the external power supply 400 to the hybrid vehicle 5 by connecting the charging cable 410, the output electric power (direct-current voltage VL) of the charger 110 may be supplied to the power supply line 155p even when the auxiliary relay RL is turned off. For example, in a state where connection of the charging cable 410 is maintained after completion of charging of the main battery 10, the charger 110 is operated in response to an on state of ACC to thereby make is possible to supply electric power for operating the auxiliary system, including the air conditioner 90, from the charger 110 without using electric power supplied from the main battery 10.

[0078] As described above, the hybrid vehicle 5 according to the first embodiment is able to completely isolate the vehicle running system, such as the PCU 20, from the main battery 10 in the external charging mode by turning off the SMR. That is, during external charging, the output voltage (direct-current voltage VL) of the main battery 10 is not applied to components of the vehicle running system, so it is possible to prevent deterioration of the durability and service life of the components due to the influence of external charging.

[0079] Furthermore, the power supply line 155p is provided separately from the power supply line 153p, and is connected to the main battery 10 via the auxiliary relay RL at a portion upstream of the SMR. Therefore, as in case of the hybrid vehicle 5#, the DC-DC converter 60 and the A/C inverter 92 are arranged closer to the PCU 20 than the main battery 10, and the auxiliaries, including the air conditioner 90, may be driven while the SMR remains off. In addition, the external charging mechanism (the inlet 105 and the charger 110) is arranged in proximity to the main battery 10 (battery pack 15). Therefore, the hybrid vehicle 5 requires a small layout change from the hybrid vehicle 5#.

[0080] Furthermore, when the main battery 10 is not charged while the charging cable 410 is connected, even when the auxiliary relay RL is turned off and the main battery 10 is not used, electric power supplied from the external power supply 400 may be used to drive the DC-DC converter 60 and the A/C inverter 92.

[0081] In this way, the hybrid vehicle 5 according to the present embodiment may have an appropriate configuration and arrangement layout of the electric system corresponding to external charging in terms of operation and design versatility during external charging.

[0082] FIG. 5 is a block diagram that shows the configuration of a hybrid vehicle 5' that is shown as a typical example of an electromotive vehicle according to an alternative embodiment to the first embodiment of the invention.

[0083] When FIG 5 is compared with FIG 1, the hybrid vehicle 5' according to the alternative embodiment to the first embodiment differs from the hybrid vehicle 5 shown in FIG 1 in that, in addition to the auxiliary relays RL1 and RL2, external charging relays CHR1 and CHR2 (hereinafter, also collectively referred to as external charging relay CHR) are additionally provided. Then, the hybrid vehicle 5' differs from the hybrid vehicle 5 in the electrical connection path between the charger .110 and the main battery 10. The external charging relay CHR corresponds to a "third switch".

[0084] Specifically, the power supply line 152p and the ground line 152g for transmitting the output electric power of the charger 110 are respectively electrically connected to the positive electrode terminal and negative electrode terminal of the main battery 10 via the external charging relays CHR1 and CHR2. As a result, the power supply line 155p and the ground line 155g are not directly connected to the power supply line 152p and the ground line 152g, and are connected to the main battery 10 via the auxiliary relays RL1 and RL2. Each of the external charging relays CHR1 and CHR2 is turned on or off by cooperation between the HV-ECU 80 and the PLG-ECU 115 as in the case of the auxiliary relay RL. Note that the PLG-ECU 115 corresponds to a "third control unit".

[0085] FIG 6 shows controls in operating states of the hybrid vehicle 5' shown in FIG 5. FIG 6 shows six cases as in the case of FIG. 4. In the hybrid vehicle 5' as well, selected power positions in each case are equal to those of FIG. 4, so the description thereof will not be repeated.

[0086] As shown in FIG. 6, when the hybrid vehicle 5' is running (vehicle running mode), the SMR and the auxiliary relay RL are turned on, while the external charging relay CHR is turned off. By so doing, the output voltage of the main battery 10 is transmitted to both the power supply lines 153p and 155p, so, as in the case of the hybrid vehicle 5, hybrid running is enabled, and the auxiliary system, including the air conditioner 90, may be driven.

[0087] _, Furthermore, in the vehicle running mode, the external charging relay CHR is turned off to completely isolate the external charging mechanism (charger 110, and the like) from the main battery 10 and the vehicle running system. As a result, even if a failure, such as a ground fault, occurs in the external charging mechanism, the operations of the auxiliaries and vehicle running are possible by eliminating the influence of the failure.

[0088] In the external charging mode, as in the case of the hybrid vehicle 5, the SMR is turned off. That is, the vehicle running system, such as the PCU 20, may be completely isolated from the main battery 10.

[0089] In the case where only external charging is performed in the external charging mode, that is, in the case where the auxiliary system, including the air conditioner 90, is not driven (ACC is set to an off state), the SMR is turned off, while the external charging relay CHR and the auxiliary relay RL are turned on. Even when ACC is set to an off state, auxiliaries associated with external charging need to operate. That is, the A/C inverter 92 is stopped because ACC is off, while the DC-DC converter 60 operates.

[0090] In addition, even in the case where the auxiliary system (including the air conditioner 90) is driven during external charging (ACC is set to an on state), the SMR is turned off, while the external charging relay CHR and the auxiliary relay RL are turned on. Then, by so doing, the DC-DC converter 60 and the air conditioner 90 (A/C inverter 92) are able to operate on electric power supplied through the power supply line 155p (direct-current voltage VL). As a result, the auxiliary system, including the air conditioner 90, may be driven during external charging.

[0091] In the hybrid vehicle 5', when the main batter 10 becomes a full charge state or when a prescribed charging time elapses, the external charging relay CHR is turned off. By so doing, the charging path from the charger 110 to the main battery 10 is interrupted.

[0092] When the hybrid vehicle 5 is not running and is not charged, there are three modes, that is, (i) ACC is on, (ii) IG is on and (iii) pre-air-conditioning mode as in the case of FIG. 3 and FIG. 4. In the hybrid vehicle 5', the auxiliary relay RL is turned on in order to drive the air conditioner 90 and/or the low-voltage loads throughout the modes (i) to (iii). On the other hand, the SMR is turned off because the vehicle is not running, and the external charging relay CHR is turned off because the vehicle is not charged. Then, in each of the modes (i) to (iii), the auxiliaries to be supplied with power are changed.

[0093] As described above, with the hybrid vehicle 5" according to the alternative embodiment to the first embodiment, in addition to the advantageous effects of the hybrid vehicle 5 (FIG. 1), the electric system may be configured to be able to achieve the operation of the auxiliary system and vehicle running by eliminating the influence of an abnormality or failure that occurs in the external charging mechanism.

[0094] FIG. 7 is a block diagram that shows the configuration of a hybrid vehicle that is shown as a typical example of an electromotive vehicle according to a second embodiment of the invention.

[0095] When FIG. 7 is compared with FIG 1, the hybrid vehicle 5 according to the second embodiment differs from the hybrid vehicle 5 (first embodiment) shown in FIG 1 in the arrangement and role of the ECU. Specifically, an HVMG-ECU 80# that integrates the HV-ECU 80 and the MG-ECU 81 shown in FIG 1 is provided, and a BAT-ECU 13 is provided instead of the battery monitoring unit 12 shown in FIG. 1.

[0096] The BAT-ECU 13 is configured to have not only the function of the battery monitoring unit 12 (FIG. 1) but also the control function when the SMR is off within the function of the HV-ECU 80 (FIG 1). Thus, the BAT-ECU 13 is configured to be able to communicate signals and data with the PLG-ECU 115, and turns on or off the auxiliary relay RL. Furthermore, the DC-DC converter 60 and the air conditioner 90 (A/C inverter 92) operate in accordance with control instructions from the BAT-ECU 13. That is, the BAT-ECU 13 corresponds to a "first control unit".

[0097] Furthermore, the BAT-ECU 13 estimates the state of charge (SOC) of the main battery 10 and sets the upper limits of charging electric power and discharging electric power for the main battery 10 instead of the HV-ECU 80 (FIG. 1). By so doing, during external charging, even when the HVMG-ECU 80# is stopped, the state of charge (SOC) of the main battery 10 may be acquired. On the other hand, during vehicle running, the BAT-ECU 13 transmits the SOC of the main battery 10 and the upper limits of charging and discharging electric powers to the HVMG-ECU 80#.

[0098] The HVMG-ECU 80# is configured to have not only the function of the MG-ECU 81 (FIG. 1) but also the control function in the vehicle rarining mode within the function of the HV-ECU 80 (FIG. 1). For example, the HVMG-ECU 80# is able to determine the distribution of output among the engine 30 and the motor generators MG1 and MG2 with limitations so as not to excessively discharge or excessively charge the main battery 10 as in the case of the HV-ECU 80 shown in FIG. 1 on the basis of the SOC of the main battery 10 and the upper limits of charging and discharging electric powers from the BAT-ECU 13. That is, the HVMG-ECU 80# corresponds to a "second control unit".

[0099] The configuration and operation of the other portions of the hybrid vehicle 5 according to the second embodiment are similar to those of the hybrid vehicle 5 (FIG 1) according to the first embodiment, so the detailed description will not be repeated. In addition, controls (power modes and relays) in operating states of the hybrid vehicle 5 according to the second embodiment may also be similar to those of the first embodiment (FIG. 4).

{0100] In the hybrid vehicle 5 according to the second embodiment, even during a stop of the vehicle running system (the SMR is off), the BAT-ECU 13 may be used to control the DC-DC converter 60 and the A/C inverter 92. That is, external charging control and auxiliary control, which are vehicle control other than in the vehicle running mode, may be executed by the BAT-ECU 13 even when the HVMG-ECU 80# is stopped. Therefore, in addition to the advantageous effects of the hybrid vehicle 5 according to the first embodiment, the HVMG-ECU 80# may be stopped during external charging or when the auxiliaries are driven while the vehicle is not running, so consumed electric power may be reduced.

[0101] FIG 8 is a block diagram that shows the configuration of a hybrid vehicle 5^ that is shown as a typical example of an electromotive vehicle according to an alternative embodiment to the second embodiment of the invention.

[0102] When FIG 8 is compared with FIG 7, the hybrid vehicle 5' according to the alternative embodiment to the second embodiment differs from the hybrid vehicle 5 shown in FIG. 7 in that, in addition to the auxiliary relays RL1 and RL2, the external charging relays CHRl and CHR2 (hereinafter, also collectively referred to as external charging relay CHR) are additionally provided. Then, the hybrid vehicle 5' according to the alternative embodiment to the second embodiment differs from the hybrid vehicle 5 according to the second embodiment in the electrical connection path between the charger 110 and the main battery 10. That is, the difference between the hybrid vehicle 5' (FIG. 8) according to the alternative embodiment to the second embodiment and the hybrid vehicle 5 (FIG. 7) according to the second embodiment is equivalent to the already described difference between the hybrid vehicle 5' (FIG. 5) according to the alternative embodiment to the first embodiment and the hybrid vehicle 5 (FIG 1) according to the first embodiment.

[0103] Thus, the hybrid vehicle 5' according to the alternative embodiment to the second embodiment corresponds to a configuration that is formed in such a manner that changes of the arrangement and role of the ECU as in the case of the hybrid vehicle 5 according to the second embodiment are added to the hybrid vehicle 5' according to the alternative embodiment to the first embodiment.

[0104] The functions of the BAT-ECU 13 and HVMG-ECU 80# are similar to those described in FIG. 7. That is, even during a stop of the vehicle running system (the SMR is off), the BAT-ECU 13 may be used to control the DC-DC converter 60 and the A/C inverter 92. Furthermore, the external charging relay CHR is turned on or off by the PLG-ECU 115. Thus, in the hybrid vehicle 5' according to the alternative embodiment to the second embodiment as well, external charging control and auxiliary control, which are vehicle control other than the vehicle running mode, may be executed by the BAT-ECU 13 and the PLG-ECU 115 even when the HVMG-ECU 80# is stopped. Therefore, the HVMG-ECU 80# operates in the vehicle running mode, while the HVMG-ECU 80# may be stopped when the vehicle is not running or during external charging.

[0105] In addition, controls (power modes and relays) in operating states of the hybrid vehicle 5' according to the alternative embodiment to the second embodiment may also be similar to those of the alternative embodiment (FIG 6) to the first embodiment.

[0106] In the hybrid vehicle 5' according to the alternative embodiment to the second embodiment, in addition to the advantageous effects of the hybrid vehicle 5' according to the alternative embodiment to the first embodiment, the HV G-ECU 80# may be stopped when the vehicle is not running or during external charging, so consumed electric power may be reduced.

[0107] Note that, in the above described embodiments and their alternative embodiments, the hybrid vehicle is illustrated as a typical example of the electromotive vehicle; instead, for an electric vehicle that is not equipped with an engine or a fuel cell vehicle that is equipped with a fuel cell as well, the configuration and arrangement layout of the electric system, including the DC-DC converter 60 and the A/C inverter 92, may be similar to those of the hybrid vehicle 5 or 5'.

[0108] The embodiment described above is illustrative and not restrictive in all respects. The scope of the invention is defined by the appended claims. The scope of the invention is intended to encompass all modifications within the scope of the appended claims and equivalents thereof.

[0109] The aspect of the invention may be applied to an electromotive vehicle that is equipped with an electrical storage device that may be charged by a power supply outside the vehicle.