阅读说明：本技术 电源系统及电动车辆 (Power supply system and electric vehicle ) 是由 加藤善久 小熊宏和 铃木健太 于 2021-03-30 设计创作，主要内容包括：提供一种电源系统,具备容量型第一蓄电装置及输出型第二蓄电装置,且能够将储存于第一蓄电装置的电力用尽。所述电源系统具备：第一电力电路,其连接有容量型第一蓄电池及驱动马达；第二电力电路,其连接有输出型第二蓄电池；电压转换器,其在第一电力电路与第二电力电路之间转换电压；及,变流器ECU及管理ECU,其操作电压转换器,以控制电压转换器中的变流器通过电力。管理ECU,在作为第一蓄电池的充电率的第一SOC不足特定的灯点亮阈值,且作为第一蓄电池的输出上限的第一输出上限P1-lim大于特定的输出阈值Pe0时,使相当于对变流器通过电力的上限的变流器通过电力上限Pcnv-max为0,并禁止第二蓄电池的放电。(Provided is a power supply system which is provided with a capacity type first power storage device and an output type second power storage device and can use up the electric power stored in the first power storage device. The power supply system includes: a first power circuit to which a capacity type first battery and a drive motor are connected; a second power circuit to which an output-type second battery is connected; a voltage converter that converts a voltage between the first power circuit and the second power circuit; and a converter ECU and a management ECU that operate the voltage converters to control the converter in the voltage converters to pass electric power. When the first SOC, which is the charging rate of the first battery, is less than a specific lamp lighting threshold and the first upper output limit P1_ lim, which is the upper output limit of the first battery, is greater than a specific output threshold Pe0, the management ECU sets the inverter passing power upper limit Pcnv _ max, which corresponds to the upper limit of the inverter passing power, to 0 and prohibits the discharge of the second battery.)

1. A power supply system is characterized by comprising:

a first power circuit to which a first power storage device and an electric load are connected;

a second power circuit to which a second power storage device having a higher output density and a lower energy density than the first power storage device is connected;

a first remaining amount parameter acquiring means for acquiring a first remaining amount parameter that increases or decreases in accordance with the remaining amount of the first power storage device;

a first output upper limit acquisition means that acquires a first output upper limit that is an output upper limit of the first power storage device;

a voltage converter that converts a voltage between the first power circuit and the second power circuit; and a process for the preparation of a coating,

a control device that operates the voltage converter to control a flow of power between the first power circuit and the second power circuit;

the control device may limit discharge of the second power storage device when the first remaining amount parameter is less than the remaining amount threshold and the first output upper limit is greater than the output threshold, as compared to a case where the first remaining amount parameter is greater than the remaining amount threshold.

2. The power supply system according to claim 1, wherein the control device permits discharge of the second power storage device when the first remaining amount parameter is less than the remaining amount threshold and the first output upper limit is less than the output threshold, as compared to a case where the first remaining amount parameter is less than the remaining amount threshold and the first output upper limit is greater than the output threshold.

3. The power supply system according to claim 2, wherein the control device sets a difference between the output threshold and the first output upper limit as an upper limit of power to be supplied from the second power circuit side to the first power circuit side at the voltage converter when the first remaining amount parameter is less than the remaining amount threshold and the first output upper limit is less than the output threshold.

4. The power supply system according to claim 1, further comprising second remaining amount parameter acquisition means for acquiring a second remaining amount parameter that increases or decreases in accordance with the remaining amount of the second power storage device;

the control device charges the second power storage device with the electric power in the first power circuit when the first remaining amount parameter is less than the remaining amount threshold, the first upper output limit is greater than the output threshold, and the second remaining amount parameter is less than the target remaining amount.

5. The power supply system according to claim 2, further comprising second remaining amount parameter acquisition means for acquiring a second remaining amount parameter that increases or decreases in accordance with the remaining amount of the second power storage device;

the control device charges the second power storage device with the electric power in the first power circuit when the first remaining amount parameter is less than the remaining amount threshold, the first upper output limit is greater than the output threshold, and the second remaining amount parameter is less than the target remaining amount.

6. The power supply system according to claim 3, further comprising second remaining amount parameter acquisition means for acquiring a second remaining amount parameter that increases or decreases in accordance with the remaining amount of the second power storage device;

the control device charges the second power storage device with the electric power in the first power circuit when the first remaining amount parameter is less than the remaining amount threshold, the first upper output limit is greater than the output threshold, and the second remaining amount parameter is less than the target remaining amount.

7. An electric vehicle equipped with the power supply system according to any one of claims 1 to 6,

the electrical load further includes:

a drive motor mechanically coupled to the drive wheel; and a process for the preparation of a coating,

and a power converter that converts power between the first power circuit and the drive motor.

8. The electrically driven vehicle according to claim 7, further comprising an information display device that can be visually confirmed by a driver,

the control device displays warning information on the state of the power supply system on the information display device when the first remaining amount parameter is less than the remaining amount threshold.

9. The electrically powered vehicle according to claim 8, wherein the warning information includes information indicating a state in which the output power of the drive motor is limited, and information on a demand for charging the first power storage device.

Technical Field

The invention relates to a power supply system and an electric vehicle. More specifically, the present invention relates to a power supply system including two power storage devices and an electrically powered vehicle having the power supply system mounted thereon.

Background

In recent years, electric vehicles such as electric transportation machines including a drive motor as a power generation source and hybrid vehicles including a drive motor and an internal combustion engine as power generation sources have been developed vigorously. Such an electrically powered vehicle is further equipped with a power storage device (a battery, a capacitor, and the like) for supplying electric energy to the drive motor. In recent years, electrically powered vehicles equipped with a plurality of power storage devices having different characteristics have also been developed.

For example, patent document 1 discloses a power supply system for an electric vehicle, including: a capacity type first power storage device mainly aiming at high capacity; and an output type second power storage device mainly aiming at high output. In the power supply system disclosed in patent document 1, when the remaining amount of a capacity type first power storage device is less than a specific threshold value, an upper limit of output of the first power storage device is calculated; further, when the upper limit output of the first power storage device is lower than the output requested by the driver, the second power storage device supplements the shortage, thereby realizing traveling in accordance with the driver's request.

[ Prior Art document ]

(patent document)

Patent document 1: japanese patent laid-open publication No. 2017-99241

Disclosure of Invention

[ problems to be solved by the invention ]

However, in the electrically powered vehicle that travels using electric power of the two power storage devices as described above, when the upper limit of the system output obtained by combining the upper limit of the output of the first power storage device and the upper limit of the output of the second power storage device is less than the specific output threshold value, the distance to empty may become 0.

Here, the following was studied: when the remaining amount of the first power storage device is less than the threshold value, that is, when the upper limit of the output of the first power storage device is in the vicinity of the output threshold value, the second power storage device supplements the shortage of the output required by the driver, as described in patent document 1. Since the second power storage device is of an output type mainly aiming at high output as described above, if a large amount of electric power is output from the second power storage device, the upper limit of the output of the second power storage device may be sharply lowered. Therefore, in the power supply system of patent document 1, the remaining travelable distance may suddenly drop to 0 before the electric power stored in the first power storage device is used up.

The present invention aims to provide a power supply system that includes a capacity type first power storage device and an output type second power storage device and that can use up electric power stored in the first power storage device, and an electrically powered vehicle equipped with the power supply system.

[ means for solving problems ]

(1) The power supply system of the present invention (for example, a power supply system 1 described later) includes: a first power circuit (for example, a first power circuit 2 described later) to which a first power storage device (for example, a first battery B1 described later) and an electric load (for example, a load circuit 4 described later) are connected; a second power circuit (for example, a second power circuit 3 described later) to which a second power storage device (for example, a second battery B2 described later) having a higher output density and a lower energy density than the first power storage device is connected; first remaining amount parameter acquisition means (for example, a first battery sensor unit 81 and a first battery ECU (electronic control unit) 74 described later) for acquiring first remaining amount parameters (for example, a first SOC (State of Charge) and a first upper output limit P1_ lim described later) that increase and decrease in accordance with the remaining amount of the first power storage device; first output upper limit acquisition means (for example, a first battery sensor unit 81 and a first battery ECU 74 described later) for acquiring a first output upper limit (for example, a first output upper limit P1_ lim described later) that is an output upper limit of the first power storage device; a voltage converter (for example, a voltage converter 5 described later) that converts a voltage between the first power circuit and the second power circuit; and a control device (for example, an electronic control unit group 7 described later) that operates the voltage converter to control the flow of electric power (for example, converter passing electric power described later) between the first power circuit and the second power circuit. The power supply system of the present invention is characterized in that: the control device limits discharge of the second power storage device when the first remaining amount parameter is less than a remaining amount threshold (for example, a lamp lighting threshold described later) and the first upper output limit is greater than an output threshold (for example, an output threshold Pe0 described later), as compared to when the first remaining amount parameter is greater than the remaining amount threshold.

(2) In this case, it is preferable that the control device allows the second power storage device to be discharged when the first remaining amount parameter is less than the remaining amount threshold and the first upper output limit is less than the output threshold, compared to a case where the first remaining amount parameter is less than the remaining amount threshold and the first upper output limit is greater than the output threshold.

(3) In this case, it is preferable that the control device sets a difference between the output threshold and the first output upper limit as an upper limit of the electric power to be supplied from the second power circuit side to the first power circuit side in the voltage converter when the first remaining parameter is less than the remaining threshold and the first output upper limit is less than the output threshold.

(4) In this case, it is preferable that the power supply system further includes a second remaining amount parameter acquiring means (for example, a second battery sensor unit 82 and a second battery ECU 75 described later) for acquiring a second remaining amount parameter (for example, a second SOC described later) that increases or decreases in accordance with the remaining amount of the second power storage device; the control device charges the second power storage device with the electric power in the first power circuit when the first remaining amount parameter is less than the remaining amount threshold, the first upper output limit is greater than the output threshold, and the second remaining amount parameter is less than the target remaining amount.

(5) An electrically powered vehicle (for example, a vehicle V described later) according to the present invention is an electrically powered vehicle (for example, a vehicle V described later) mounted with the power supply system described in any one of (1) to (4), wherein the electrical load includes: a drive motor (e.g., a drive motor M described later) mechanically coupled to a drive wheel (e.g., a drive wheel W described later); and a power converter (for example, a power converter 43 described later) that converts electric power between the first power circuit and the drive motor.

(6) In this case, it is preferable that the electrically powered vehicle further includes an information display device (for example, a monitor 92 described later) that is visually recognizable by a driver, and the control device displays warning information regarding the state of the power supply system on the information display device when the first remaining amount parameter is less than the remaining amount threshold.

(7) In this case, the warning information preferably includes information indicating a state in which the output power of the drive motor is limited, and information on a demand for charging the first power storage device.

(Effect of the invention)

(1) In the present invention, a first power circuit to which a capacity type first power storage device and an electric load are connected and a second power circuit to which an output type second power storage device is connected are connected by a voltage converter, and the flow of electric power between the first power circuit and the second power circuit, that is, the charging and discharging of the second power storage device are controlled by operating the voltage converter by a control device. Here, the second output upper limit of the output type second power storage device is lowered faster than the first output upper limit of the capacity type first power storage device. Therefore, for example, when the first remaining amount parameter gradually decreases and becomes insufficient to the remaining amount threshold, if the first output upper limit is larger than the output threshold, the system output upper limit, which is the sum of the first output upper limit and the second output upper limit, may be lower than the output threshold before the electric power stored in the first power storage device is used up, unless the discharge of the second power storage device is restricted and the discharge is allowed to continue. In contrast, in the present invention, when the first remaining amount parameter of the first power storage device is less than the remaining amount threshold and the first output upper limit is greater than the output threshold, the control device limits the discharge of the second power storage device as compared to a case where the first remaining amount parameter is greater than the remaining amount threshold. Thus, the assist electric power in the second power storage device can be ensured until the first output upper limit of the first power storage device becomes lower than the output threshold. Therefore, according to the present invention, after the first upper output limit is lower than the output threshold, the electric load can be supplied with the required electric power using the electric power from the second power storage device, and therefore, the electric power stored in the first power storage device can be used up.

(2) In the present invention, the control device allows the second power storage device to discharge when the first remaining amount parameter is less than the remaining amount threshold and the first output upper limit is less than the output threshold, compared to a case where the first remaining amount parameter is less than the remaining amount threshold and the first output upper limit is greater than the output threshold. Therefore, when the first output upper limit is less than the output threshold, the shortage (output threshold — first output upper limit) is supplemented with the electric power secured in the second power storage device while the first output upper limit is greater than the output threshold as described above, so that it is possible to prevent the overall system output obtained by integrating the first power storage device and the second power storage device from falling below the output threshold, and further, it is possible to use up the electric power stored in the first power storage device.

(3) In the present invention, when the first remaining amount parameter is less than the remaining amount threshold and the first output upper limit is less than the output threshold, the control device sets a difference between the output threshold and the first output upper limit as an upper limit of electric power to be passed from the second power circuit side to the first power circuit side at the voltage converter. This can suppress a sudden decrease in the remaining amount of the second power storage device, and therefore, the electric power stored in the first power storage device can be used up.

(4) In the present invention, the control device charges the second power storage device with the electric power in the first power circuit when the first remaining amount parameter is less than the remaining amount threshold, the first upper output limit is greater than the output threshold, and the second remaining amount parameter is less than the target remaining amount. Thus, it is possible to prepare for increasing the remaining amount of the second power storage device after the first output upper limit of the first power storage device is lower than the output threshold value. Therefore, according to the present invention, since it is possible to ensure that the time during which the second power storage device can assist after the first upper output limit is lower than the output threshold value is long, the electric power stored in the first power storage device can be used up.

(5) According to the electrically powered vehicle of the present invention, the travel by the drive motor can be continued until the electric power stored in the first power storage device is used up.

(6) In the present invention, when the first remaining amount parameter is less than the remaining amount threshold and the first output upper limit is greater than the output threshold, the discharge of the second power storage device is restricted as compared to a case where the first remaining amount parameter is greater than the remaining amount threshold. Therefore, the electric vehicle cannot supply electric power that meets the driver's demand to the drive motor, and the driver may feel discomfort. In contrast, when the first remaining amount parameter is less than the remaining amount threshold, the control device displays warning information about the state of the power supply system on the information display device. This can reduce the discomfort felt by the driver.

(7) In the present invention, the control device displays information indicating a state in which the output power to the drive motor is limited and information on the demand for charging the first power storage device on the information display device as warning information. According to the present invention, it is possible to reduce the uncomfortable feeling of the driver when the output to the drive motor is limited, and to prompt charging of the first power storage device.

Drawings

Fig. 1 is a diagram showing a configuration of a vehicle mounted with a power supply system according to an embodiment of the present invention.

Fig. 2 is a diagram showing an example of a circuit configuration of the voltage converter.

Fig. 3 is a flowchart showing a specific sequence of the power management process.

Fig. 4 is a flow chart showing a sequence of calculating the upper limit of the power passing through the converter.

Fig. 5 is a flowchart showing a sequence of calculating an upper limit of the inverter passing power.

Fig. 6 is a graph showing changes in the first output upper limit and the system output when the first SOC is lowered to around the lamp lighting threshold.

Detailed Description

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a diagram showing a configuration of an electrically powered vehicle V (hereinafter simply referred to as a "vehicle") on which a power supply system 1 of the present embodiment is mounted.

The vehicle V includes: a drive wheel W; a drive motor M connected to the drive wheel W; and a power supply system 1 that transmits and receives electric power between the drive motor M and a first battery B1 and a second battery B2, which will be described later. In the present embodiment, the vehicle V is explained by taking as an example the case where the vehicle is accelerated and decelerated mainly by the power generated by the drive motor M, but the present invention is not limited to this. The vehicle V may be a so-called hybrid vehicle in which a drive motor M and an engine are mounted as power generation sources.

The drive motor M is coupled to the drive wheels W via a power transmission mechanism not shown. When the three-phase ac power is supplied from the power supply system 1 to the drive motor M, the torque generated by the drive motor M is transmitted to the drive wheels W via a power transmission mechanism, not shown, and the vehicle V travels by rotating the drive wheels W. The drive motor M functions as a generator when the vehicle V decelerates, generates regenerative electric power, and applies regenerative braking torque corresponding to the magnitude of the regenerative electric power to the drive wheels W. The regenerative power generated by the drive motor M appropriately charges the batteries B1 and B2 of the power supply system 1.

The power supply system 1 includes: a first power circuit 2 to which a first battery B1 is connected; a second power circuit 3 to which a second battery B2 is connected; a voltage converter 5 that connects the first power circuits 2 and the second power circuit 3; a load circuit 4 having various electric loads including a drive motor M; and an electronic control unit group 7 that controls the power circuits 2,3,4 and the voltage converter 5. The electronic control unit group 7 includes a management ECU71, a motor ECU 72, an inverter ECU 73, a first battery ECU 74, and a second battery ECU 75, which are computers, respectively.

First battery B1 is a secondary battery that can perform both discharge for converting chemical energy into electric energy and charge for converting electric energy into chemical energy. Hereinafter, a case where a so-called lithium ion secondary battery in which lithium ions are moved between electrodes to be charged and discharged is used as the first secondary battery B1 will be described, but the present invention is not limited thereto.

The first battery B1 is provided with a first battery sensor unit 81, and the first battery sensor unit 81 estimates the internal state of the first battery B1. The first battery sensor unit 81 is constituted by a plurality of sensors that detect physical quantities required for acquiring a charging rate (a storage amount of the battery in percentage) corresponding to the remaining amount of the first battery B1, a temperature, and the like in the first battery ECU 74, and transmit a signal corresponding to the detected value to the first battery ECU 74. More specifically, the first battery sensor unit 81 includes a voltage sensor for detecting a terminal voltage of the first battery B1, a current sensor for detecting a current flowing through the first battery B1, a temperature sensor for detecting a temperature of the first battery B1, and the like.

Second battery B2 is a secondary battery that can perform both discharge for converting chemical energy into electric energy and charge for converting electric energy into chemical energy. Hereinafter, a case where a so-called lithium ion secondary battery in which lithium ions are moved between electrodes to be charged and discharged is used as the second secondary battery B2 will be described, but the present invention is not limited thereto. For example, a capacitor may be used as second battery B2.

The second battery B2 is provided with a second battery sensor unit 82, and the second battery sensor unit 82 estimates the internal state of the second battery B2. The second battery sensor unit 82 is constituted by a plurality of sensors that detect physical quantities required for acquiring the charging rate, temperature, and the like of the second battery B2 in the second battery ECU 75, and transmit signals corresponding to the detected values to the second battery ECU 75. More specifically, the second battery sensor unit 82 is configured by a voltage sensor that detects a terminal voltage of the second battery B2, a current sensor that detects a current flowing through the second battery B2, a temperature sensor that detects a temperature of the second battery B2, and the like.

Here, the characteristics of the first battery B1 are compared with the characteristics of the second battery B2.

The first battery B1 has a lower output weight density and a higher energy weight density than the second battery B2. And the capacity of the first secondary battery B1 is larger than that of the second secondary battery B2. That is, the first secondary battery B1 is superior in energy weight density to the second secondary battery B2. The energy density is an amount of electricity per unit weight [ Wh/kg ], and the output density is an amount of electricity per unit weight [ W/kg ]. Therefore, the first battery B1, which is excellent in energy weight density, is a capacity type battery mainly aiming at high capacity, and the second battery B2, which is excellent in output weight density, is an output type battery mainly aiming at high output. Therefore, in the power supply system 1, the first secondary battery B1 is used as a main power supply, and the second secondary battery B2 is used as a secondary power supply that assists this first secondary battery B1.

The first power circuit 2 includes: a first battery B1; first power lines 21p,21n connecting the positive and negative poles of first battery B1 to the positive and negative terminals of the high-voltage side of voltage converter 5; and a positive electrode contact 22p and a negative electrode contact 22n provided on the first power lines 21p,21 n.

Contactors 22p,22n are of a normally open type, which are opened in a state where no command signal is input from the outside to cut off conduction between both electrodes of first battery B1 and first power lines 21p,21 n; and is closed to connect first battery B1 with first power lines 21p,21n in a state where the command signal is input. These contactors 22p,22n are opened and closed in accordance with a command signal transmitted from the first battery ECU 74. The positive electrode contactor 22p is a precharge contactor having a precharge resistor for relaxing an inrush current of a plurality of smoothing capacitors provided in the first power circuit 2, the load circuit 4, and the like.

The second power circuit 3 includes: a second battery B2; second power lines 31p,31n connecting the positive and negative poles of second battery B2 to the positive and negative terminals on the low-voltage side of voltage converter 5; a positive electrode contact 32p and a negative electrode contact 32n provided on the second power lines 31p and 31 n; and a current sensor 33 provided on the second power line 31 p.

Contactors 32p,32n are of a normally open type, which are opened in a state where no command signal is input from the outside to cut off conduction between both electrodes of second battery B2 and second power lines 31p,31 n; and is closed to connect second battery B2 with second power lines 31p,31n in the state where the command signal is input. These contactors 32p,32n are opened and closed in accordance with a command signal transmitted from the second battery ECU 75. The positive electrode contactor 32p is a precharge contactor having a precharge resistor for relaxing an inrush current of a plurality of smoothing capacitors provided in the first power circuit 2, the load circuit 4, and the like.

The current sensor 33 transmits a detection signal corresponding to the current flowing in the second power line 31p, that is, the passing current as the current flowing in the voltage converter 5, to the inverter ECU 73. In the present embodiment, the flow of the passing current is positive from the second power circuit 3 side toward the first power circuit 2 side, and is negative from the first power circuit 2 side toward the second power circuit 3 side.

The load circuit 4 includes: the vehicle auxiliary machine 42; a power converter 43 to which a drive motor M is connected; and load power lines 41p,41n connecting the vehicle auxiliary devices 42 and the power converter 43 to the first power circuit 2.

The vehicle auxiliary device 42 is configured by a plurality of electric loads such as a battery heater, an air compressor, a DC-DC (direct current-direct current) converter, and an in-vehicle charger. Vehicle auxiliary unit 42 is connected to first power lines 21p,21n of first power circuit 2 by load power lines 41p,41n, and operates by consuming electric power in first power lines 21p,21 n. Information on the operating states of various electrical loads constituting the vehicle auxiliary machine 42 is sent to, for example, the management ECU 71.

Power converter 43 is connected to first power lines 21p,21n in parallel with vehicle auxiliary machine 42 by load power lines 41p,41 n. The power converter 43 converts electric power between the first power lines 21p,21n and the drive motor M. The power converter 43 is a PWM inverter using pulse width modulation, for example, having a bridge circuit configured by bridging a plurality of switching elements (e.g., IGBTs, insulated gate bipolar transistors), and has a function of converting dc power and ac power. The power converter 43 is connected to the first power lines 21p,21n on the dc input/output side thereof, and to the coils of the U-phase, V-phase, and W-phase of the drive motor M on the ac input/output side thereof. The power converter 43 drives the switching elements of each phase to be turned on/off in accordance with a gate drive signal generated at a specific time by a gate drive circuit, not shown, of the motor ECU 72, thereby converting the dc power in the first power lines 21p,21n into three-phase ac power and supplying the three-phase ac power to the drive motor M, or converting the three-phase ac power supplied from the drive motor M into dc power and supplying the dc power to the first power lines 21p,21 n.

The voltage converter 5 connects the first power circuit 2 and the second power circuit 3, and converts a voltage between these two circuits 2, 3. This voltage converter 5 uses a known booster circuit.

Fig. 2 is a diagram showing an example of the circuit configuration of the voltage converter 5. The voltage converter 5 connects the first power lines 21p,21n to which the first battery B1 is connected and the second power lines 31p,31n to which the second battery B2 is connected, and converts the voltage between these first power lines 21p,21n and the second power lines 31p,31 n. The voltage converter 5 is a full-bridge DC-DC converter, and is configured by combining a first reactor L1, a second reactor L2, a first high-arm element 53H, a first low-arm element 53L, a second high-arm element 54H, a second low-arm element 54L, a negative bus 55, low-voltage-side terminals 56p,56n, high-voltage-side terminals 57p,57n, and a smoothing capacitor, not shown.

The low-voltage side terminals 56p,56n are connected to the second power lines 31p,31n, and the high-voltage side terminals 57p,57n are connected to the first power lines 21p,21 n. The negative bus 55 is a wire connecting the low-voltage-side terminal 56n and the high-voltage-side terminal 57 n.

One end side of the first reactor L1 is connected to the low-voltage-side terminal 56p, and the other end side is connected to the connection node 53 of the first high-arm element 53H and the first low-arm element 53L. Each of the first high arm element 53H and the first low arm element 53L includes a known power switching element such as an IGBT or a MOSFET (metal-oxide semiconductor field effect transistor), and a free wheeling diode connected to the power switching element. These high-arm element 53H and low-arm element 53L are connected in series between the high-voltage-side terminal 57p and the negative bus bar 55 in this order.

The power switching element of the first high arm element 53H has a collector connected to the high voltage side terminal 57p and an emitter connected to the collector of the first low arm element 53L. The emitter of the power switching element of the first lower arm element 53L is connected to the negative bus bar 55. The forward direction of the free wheeling diode provided in the first high arm element 53H is the direction from the first reactor L1 to the high-voltage-side terminal 57 p. The forward direction of the free wheeling diode provided in the first low arm element 53L is the direction from the negative bus 55 to the first reactor L1.

The second reactor L2 has one end connected to the low-voltage-side terminal 56p and the other end connected to the connection node 54 of the second high-arm element 54H and the second low-arm element 54L. The second high arm element 54H and the second low arm element 54L each include a known power switching element such as an IGBT or a MOSFET, and a free wheeling diode connected to the power switching element. These high-arm element 54H and low-arm element 54L are connected in series between the high-voltage-side terminal 57p and the negative bus bar 55 in this order.

The collector of the power switching element of the second high-arm element 54H is connected to the high-voltage-side terminal 57p, and the emitter thereof is connected to the collector of the second low-arm element 54L. The emitter of the power switching element of the second lower arm element 54L is connected to the negative bus bar 55. The forward direction of the free wheeling diode provided on the second high arm element 54H is the direction from the second reactor L2 toward the high-voltage-side terminal 57 p. And the forward direction of the free wheeling diode provided on the second lower arm element 54L is the direction from the negative bus bar 55 toward the second reactor L2.

The voltage converter 5 alternately performs on/off driving of the first high arm device 53H and the second low arm device 54L and the first low arm device 53L and the second high arm device 54H based on a gate drive signal generated at a specific time by a gate drive circuit, not shown, of the inverter ECU 73, thereby converting a voltage between the first power lines 21p,21n and the second power lines 31p,31 n.

The static voltage of the second secondary battery B2 is maintained substantially lower than the static voltage of the first secondary battery B1. Therefore, the voltage of the first power lines 21p,21n is substantially higher than the voltage of the second power lines 31p,31 n. Therefore, when the drive motor M is driven using both the electric power output by the first battery B1 and the electric power output by the second battery B2, the inverter ECU 73 operates the voltage converter 5 to exert the boosting function in the voltage converter 5. The boost function is a function of boosting the power in the second power lines 31p,31n connected to the low-voltage side terminals 56p,56n and outputting the boosted power to the first power lines 21p,21n connected to the high-voltage side terminals 57p,57n, whereby a positive passing current flows from the second power lines 31p,31n side toward the first power lines 21p,21n side. When the drive motor M is driven by only the electric power output from the first battery B1 while suppressing the discharge of the second battery B2, the inverter ECU 73 turns off the voltage converter 5 so that the electric current does not flow from the first power lines 21p,21n to the second power lines 31p,31 n.

When the first battery B1 or the second battery B2 is charged with regenerative electric power output from the drive motor M to the first power lines 21p,21n during deceleration, the inverter ECU 73 operates the voltage converter 5 to cause the voltage converter 5 to perform a step-down function. The voltage-reducing function is a function of reducing the voltage of the power on the first power lines 21p,21n connected to the high-voltage side terminals 57p,57n and outputting the reduced voltage to the second power lines 31p,31n connected to the low-voltage side terminals 56p,56n, whereby a negative through current flows from the first power lines 21p,21n side toward the second power lines 31p,31n side.

Returning to fig. 1, the first battery ECU 74 is a computer mainly responsible for monitoring the state of the first battery B1 and for switching the contactors 22p,22n of the first power circuit 2. The first battery ECU 74 calculates various parameters indicating the internal state of the first battery B1, more specifically, the temperature of the first battery B1, the internal resistance of the first battery B1, the static voltage of the first battery B1, the closed circuit voltage of the first battery B1, the first upper output limit equivalent to the electric power that can be output by the first battery B1, the first SOC equivalent to the charging rate of the first battery B1, and the like, based on a known algorithm using the detection values sent from the first battery sensor unit 81. Therefore, in the present embodiment, the first remaining amount parameter acquisition means and the first output upper limit acquisition means are constituted by the first battery sensor unit 81 and the first battery ECU 74. The information on the parameters indicating the internal state of the first battery B1 acquired at the first battery ECU 74 is sent to the management ECU71, for example.

The second battery ECU 75 is a computer that is mainly responsible for monitoring the state of the second battery B2 and for switching the contactors 32p,32n of the second power circuit 3. The second battery ECU 75 calculates various parameters indicating the internal state of the second battery B2, more specifically, the temperature of the second battery B2, the internal resistance of the second battery B2, the static voltage of the second battery B2, the closed circuit voltage of the second battery B2, a second upper output limit equivalent to the electric power that can be output by the second battery B2, a second SOC equivalent to the charging rate of the second battery B2, and the like, based on a known algorithm using the detection values sent by the second battery sensor unit 82. Therefore, in the present embodiment, the second remaining amount parameter acquisition means and the second output upper limit acquisition means are constituted by the second battery sensor unit 82 and the second battery ECU 75. The information on the parameters indicating the internal state of the second battery B2 acquired at the second battery ECU 75 is sent to the management ECU71, for example.

The management ECU71 is a computer that mainly manages the flow of electric power in the entire power supply system 1. The management ECU71 performs the power management processing described later with reference to fig. 4, thereby generating a torque command signal corresponding to a command for torque generated by the drive motor M and a converter passing power command signal corresponding to a command for passing power to the converter, which is power passing through the voltage converter 5.

The management ECU71 is connected to a charge demand lamp 91, a monitor 92, and a remaining travel distance meter 93. The charge demand lamp 91, the monitor 92, and the remaining travel distance meter 93 are provided at positions that can be visually confirmed by the driver.

The charge demand lamp 91 is one of the notification means for prompting the driver to charge the first storage battery B1. The control ECU71 turns off the charge demand lamp 91 when the first SOC is greater than a specific lamp lighting threshold (see, for example, fig. 6 described later), and turns on the charge demand lamp 91 when the first SOC becomes equal to or less than the lamp lighting threshold. This prompts the driver to charge the first battery B1. Since the first SOC and the first upper output limit are in a substantially proportional relationship, the management ECU71 may turn off or on the charge demand lamp 91 by comparing the first upper output limit with a specific threshold value.

The remaining distance meter 93 is one of the notification means for notifying the driver of the remaining distance to be traveled, which is the distance that the driver can travel. The management ECU71 calculates the distance to empty using a known algorithm using the first SOC, the second SOC, the first upper output limit, and the second upper output limit, and displays the value on the distance to empty meter 93. At this time, when the system output upper limit, which is the sum of the first output upper limit and the second output upper limit, is less than a specific output threshold (for example, see fig. 6 described later), the management ECU71 sets the distance to empty to 0.

The monitor 92 is an information display device that displays warning information regarding the state of the power supply system 1 by characters, graphics, or the like, thereby notifying the driver of the state of the power supply system 1. The contents of the warning information and the timing of displaying the warning information on the monitor 92 will be described later with reference to fig. 4.

The motor ECU 72 is a computer that mainly operates the power converter 43, and controls the flow of electric power between the first power circuit 2 and the drive motor M, that is, the flow of inverter passing electric power as electric power passing through the power converter 43. When electric power flows from the first power circuit 2 to the drive motor M, that is, when the drive motor M is in power operation, the inverter passing electric power is positive. When electric power flows from the drive motor M to the first power circuit 2, that is, during regenerative operation of the drive motor M, the inverter passing electric power is negative. The motor ECU 72 operates the power converter 43 based on a torque command signal calculated by the management ECU71 based on a command for the inverter to supply electric power, so that a torque corresponding to the command is generated in the drive motor M.

The converter ECU 73 is a computer that mainly operates the voltage converter 5 to control the flow of electric power between the first power circuit 2 and the second power circuit 3, that is, the flow of converter passing electric power as electric power passing through the voltage converter 5. When electric power flows from the second power circuit 3 to the first power circuit 2, that is, when electric power is discharged from the second battery B2 and supplied to the first power circuit 2, the inverter passing electric power is positive. And when electric power flows from the first power circuit 2 to the second power circuit 3, that is, when the second storage battery B2 is charged with electric power in the first power circuit 2, the converter passing electric power is negative. The inverter ECU 73 operates the voltage converter 5 in accordance with the inverter passing power command signal transmitted from the management ECU71 so that the inverter corresponding to the command passes power through the voltage converter 5. More specifically, the converter ECU 73 calculates a target current as a target for the through current in the voltage converter 5 based on the converter-passing electric power command signal, and operates the voltage converter 5 according to a known feedback control algorithm so that the through current detected by the current sensor 33 (hereinafter also referred to as "actual through current") becomes the target current.

Fig. 3 is a flowchart showing a specific sequence of the power management process. This power management process is repeatedly executed in the management ECU71 at a certain cycle until the remaining travelable distance becomes 0, that is, the upper limit of the system output is equal to or less than the output threshold.

First, in S1, the management ECU71 calculates the auxiliary machine electric power Paux, which is the electric power required by the vehicle auxiliary machine 42, and proceeds to S2. The management ECU71 calculates the required auxiliary machine electric power Paux based on the information on the operating states of the various electrical loads transmitted from the vehicle auxiliary machine 42.

At S2, the management ECU71 calculates required inverter passing power Pmot _ d corresponding to a request for inverter passing power at the power converter 43, and proceeds to S3. The management ECU71 calculates the required inverter passing power Pmot _ d by calculating the required driving torque of the driver based on the operation amount of the pedals P (see fig. 1) such as an accelerator pedal and a brake pedal of the driver and converting the required driving torque into electric power.

At S3, the management ECU71 calculates an inverter passing power upper limit Pcnv _ max corresponding to the upper limit of the inverter passing power to the voltage converter 5, and proceeds to S4. The specific procedure for calculating the converter passing power upper limit Pcnv _ max will be described in detail later with reference to fig. 4.

At S4, the management ECU71 calculates an inverter passing power upper limit Pmot _ max corresponding to the upper limit of the inverter passing power to the power converter 43, and proceeds to S5. A specific procedure for calculating the inverter passing power upper limit Pmot _ max will be described in detail later with reference to fig. 5.

In S5, the management ECU71 determines whether the required inverter passing power Pmot _ d is equal to or less than the inverter passing power upper limit Pmot _ max.

When the determination result in S5 is "yes" (when Pmot _ d ≦ Pmot _ max), the management ECU71 moves to S8 with the requested inverter passing power Pmot _ d calculated in S2 as the target inverter passing power Pmot _ cmd (refer to S6) corresponding to the target of the inverter passing power to the power converter 43.

When the determination result in S5 is no (when Pmot _ d > Pmot _ max), the management ECU71 sets the inverter passing power upper limit Pmot _ max calculated by the process in S4 as the target inverter passing power Pmot _ cmd (refer to S7), and moves to S8.

At S8, the management ECU71 calculates target converter passing power Pcnv _ cmd corresponding to a target of passing power to the converter in the voltage converter 5, and then proceeds to S9. More specifically, the management ECU71 calculates the target converter passing power Pcnv _ cmd such that the first battery B1 and the second battery B2 are charged and discharged at a specific rate within a range of the converter passing power upper limit Pcnv _ max or less.

Further, preferably, the management ECU71 makes the converter passing power upper limit Pcnv _ max smaller than the second output upper limit of the second battery B2, thereby positively charging the second battery B2 with the electric power in the first electric power circuit 2 while positively setting the target converter passing power Pcnv _ cmd to less than 0 when the discharge period of the second battery B2 is limited by the second output upper limit (see S27 in fig. 4 described later) and the second SOC is less than the specific target second SOC.

At S9, the management ECU71 generates a converter passing power command signal corresponding to the target converter passing power Pcnv _ cmd calculated at S8, transmits the generated signal to the converter ECU 73, and moves to S10. Thereby, the second battery B2 is charged and discharged with electric power corresponding to the target converter passing electric power Pcnv _ cmd.

At S10, the management ECU71 generates a torque command signal based on the target inverter passing power Pmot _ cmd calculated at S6 or S7, transmits the torque command signal to the motor ECU 72, and ends the power management process. More specifically, the management ECU71 converts the target inverter passing electric power Pmot _ cmd into a torque to calculate a target drive torque, and generates a torque command signal corresponding to the target drive torque. The motor ECU 72 operates the electric power converter 43 based on the torque command signal. Thereby, electric power corresponding to the target inverter passing electric power Pmot _ cmd flows between the first electric power circuit 2 and the drive motor M.

Fig. 4 is a flowchart showing the sequence of calculating the converter passing power upper limit Pcnv _ max.

First in S21, the management ECU71 acquires the second upper output limit P2_ lim, and moves to S22. In S22, the management ECU71 determines whether the charge demand lamp 91 is lighting, that is, whether the first SOC is equal to or less than the lamp lighting threshold.

When the determination result at S22 is "no", that is, when the first SOC is greater than the lamp lighting threshold value, the management ECU71 proceeds to S23, and proceeds to the process at S4 in fig. 3 with the second upper output limit P2_ lim as the converter passing power upper limit Pcnv _ max.

If the determination result at S22 is yes, that is, if the first SOC is equal to or less than the lamp lighting threshold value, the management ECU71 proceeds to S24.

In S24, the management ECU71 displays specific warning information on the monitor 92, and proceeds to S25. As described below, when the first SOC is equal to or less than the lamp lighting threshold, the output of second battery B2 is limited, and therefore, the request of the driver may not be fulfilled and the driver may feel uncomfortable. Therefore, at S24, the management ECU71 displays on the monitor 92 information indicating that the state of the output power to the drive motor M is currently restricted, and main information prompting the prompt charging of the first battery B1.

In S25, the management ECU71 acquires the first upper output limit P1_ lim, and moves to S26. In S26, the management ECU71 determines whether the first upper output limit P1_ lim is the output threshold Pe0 or less.

If the determination result at S26 is "no", that is, if the first SOC is equal to or less than the lamp lighting threshold and the first upper output limit P1_ lim is greater than the output threshold Pe0, the management ECU71 proceeds to S27. At S27, the management ECU71 sets the converter passing power upper limit Pcnv _ max to 0, that is, prohibits the discharge of the second battery B2, and proceeds to the process at S4 of fig. 3.

If the determination result at S26 is yes, that is, if the first SOC is equal to or less than the lamp lighting threshold and the first upper output limit P1_ lim is equal to or less than the output threshold Pe0, the management ECU71 proceeds to S28. At S28, the management ECU71 calculates the reinforcement permission output P2bst for the second battery B2, and proceeds to S29. More specifically, the management ECU71 subtracts the first output upper limit P1_ lim from the output threshold Pe0 to calculate the reinforcement permission output P2bst (P2 bst: Pe0-P1_ lim). That is, the difference between the output threshold Pe0 and the first output upper limit P1_ lim is set as the reinforcement permission output P2 bst.

In S29, the management ECU71 moves the reinforcement permission output P2bst to the process of S4 in fig. 3 as the converter passing electric power upper limit Pcnv _ max. That is, when the first SOC is equal to or less than the lamp lighting threshold and the first upper output limit P1_ lim is equal to or less than the output threshold Pe0, the management ECU71 allows the discharge of the second battery B2 by setting the inverter passing power upper limit Pcnv _ max to a value greater than 0. That is, when the first SOC is equal to or less than the lamp lighting threshold and the first upper output limit P1_ lim is equal to or less than the output threshold Pe0, the management ECU71 allows the discharge of the second battery B2 by setting the converter passing power upper limit Pcnv _ max to a larger value than when the first SOC is equal to or less than the lamp lighting threshold and the first upper output limit P1_ lim is greater than the output threshold Pe 0.

Fig. 5 is a flowchart showing the sequence of calculating the inverter passing electric power upper limit Pmot _ max.

First in S31, the management ECU71 acquires the first upper output limit P1_ lim, and moves to S32. In S32, the management ECU71 determines whether the first upper output limit P1_ lim is the output threshold Pe0 or less.

When the determination result at S32 is "no", that is, when the first output upper limit P1_ lim is greater than the output threshold Pe0, the control ECU71 moves to S33, subtracts the required auxiliary machine power Paux acquired at S1 of fig. 3 from the sum of the first output upper limit P1_ lim acquired at S31 and the converter passing power upper limit Pcnv _ max calculated by the processing of fig. 4, thereby calculates the inverter passing power upper limit Pmot _ max (Pmot _ max is P1_ lim + Pcnv _ max-Paux), and moves to the processing of S5 of fig. 3.

If the determination result at S32 is yes, that is, if the first output upper limit P1_ lim is equal to or less than the output threshold Pe0, the management ECU71 proceeds to S34, and proceeds to the process at S5 of fig. 3, with the first output upper limit P1_ lim obtained at S31 being the inverter passing electric power upper limit Pmot _ max (Pmot _ max is P1_ lim).

Fig. 6 is a graph showing changes in the first upper output limit P1_ lim (broken line) and the system output Psys (solid line) when the first SOC is lowered around the lamp lighting threshold. The system output Psys here refers to the sum of the electric power output by the first battery B1 and the electric power output by the second battery B2. In the example of fig. 6, for the sake of easy understanding, the required auxiliary machinery electric power Paux is set to 0, and the required inverter passing electric power Pmot _ d is always set to the maximum.

When the first SOC is greater than the lamp lighting threshold, electric power is output from first battery B1 and second battery B2, and thus, as the first SOC decreases, first upper output limit P1_ lim also decreases. Therefore, the system output Psys gradually decreases along the route C1 as the first upper output limit P1_ lim decreases.

When the first SOC is equal to or lower than the lamp lighting threshold value and the first output upper limit P1_ lim of the first battery B1 is greater than the output threshold value Pe0, the management ECU71 sets the converter passing power upper limit Pcnv _ max to 0 and prohibits the discharge of the second battery B2 (see S22, S24, S5, S26, and S27 in fig. 4). Therefore, the system output Psys is reduced to the first upper output limit P1_ lim along the route C2. At this time, when the second SOC falls below the target second SOC while the discharge of the second secondary battery B2 is prohibited, the second secondary battery B2 is positively charged with the electric power in the first electric power circuit 2 (see reference to S8 in fig. 3).

After that, when the first output upper limit P1_ lim of the first battery B1 has decreased to the output threshold Pe0, the management ECU71 sets the first output upper limit P1_ lim to the inverter passing electric power upper limit Pmot _ max, and limits the electric power supplied from the first electric power circuit 2 to the drive motor M to the first output upper limit P1_ lim or less (see S32 and S34 of fig. 5). And once the first upper output limit P1_ lim has decreased to the output threshold Pe0, the management ECU71 permits discharge of the second battery B2 to supplement the shortage of the first battery B1 (refer to S26, S28, S29 of fig. 4). Thus, the system output Psys follows a route C3 on the output threshold Pe 0. Thereafter, once the first output upper limit P1_ lim is lowered and the system output upper limit, which is the sum of the first output upper limit P1_ lim and the second output upper limit P2_ lim, is less than the output threshold Pe0, the remaining travelable distance becomes 0. This can run out the electric power stored in first battery B1 until the distance to empty becomes 0.

According to the power supply system 1 and the vehicle V of the present embodiment, the following effects are exhibited.

(1) In the power supply system 1, the first power circuit to which the capacity type first battery B1 and the load circuit 4 are connected and the second power circuit 3 to which the output type second battery B2 is connected are connected by the voltage converter 5, and the charging and discharging of the converter-passing power, that is, the second battery B2 is controlled by operating the voltage converter 5 by the converter ECU 73. Here, the second upper output limit P2_ lim of the output type second battery B2 is lower than the first upper output limit P1_ lim of the capacity type first battery B1. Therefore, for example, when the first SOC is insufficient for the lamp lighting threshold and the first output upper limit P1_ lim is greater than the output threshold Pe0, if the discharge of the second battery B2 is permitted, the sum of the first output upper limit P1_ lim and the second output upper limit P2_ lim, that is, the system output upper limit may be lower than the output threshold Pe0 before the electric power stored in the first battery B1 is used up. In contrast, in the power supply system 1, the management ECU71 prohibits the discharge of the second battery B2 when the first SOC of the first battery B1 is less than the lamp lighting threshold and the first upper output limit P1_ lim is greater than the output threshold Pe 0. Thus, the auxiliary power can be secured in the second battery B2 until the first upper output limit P1_ lim of the first battery B1 is lower than the output threshold Pe 0. Therefore, according to the power supply system 1, after the first output upper limit P1_ lim is lower than the output threshold Pe0, the required electric power can be supplied to the load circuit 4 by the electric power from the second battery B2, and therefore, the electric power stored in the first battery B1 can be used up.

(2) In the power supply system 1, the management ECU71 permits the discharge of the second battery B2 when the first SOC falls short of the lamp lighting threshold and the first upper output limit P1_ lim falls short of the output threshold Pe 0. Thus, when the first output upper limit P1_ lim is less than the output threshold Pe0, as described above, the shortage can be replenished with the electric power secured to the second battery B2 (the output threshold Pe0 — the first output upper limit P1_ lim) while the first output upper limit P1_ lim is greater than the output threshold Pe0, so that the overall system output obtained by integrating the first battery B1 and the second battery B2 can be prevented from falling below the output threshold Pe0, and the electric power stored in the first battery B1 can be used up.

(3) In the power supply system 1, the management ECU71 limits the power supplied from the first power circuit 2 to the load circuit 4 to the output threshold Pe0 or less when the first SOC is less than the lamp lighting threshold and the first output upper limit P1_ lim is less than the output threshold Pe 0. This makes it possible to limit the output from the second battery B2, and therefore, the electric power stored in the first battery B1 can be used up.

(4) In the power supply system 1, the management ECU71 charges the second battery B2 with the electric power in the first electric power circuit 2 when the discharge of the second battery B2 is prohibited and the second SOC is less than the target second SOC. Thus, it is possible to prepare for increasing the remaining amount of the second battery B2 after the first output upper limit P1_ lim of the first battery B1 is lower than the output threshold Pe 0. Therefore, according to power supply system 1, since the time that can be assisted by second battery B2 is long after first upper output limit P1_ lim is lower than output threshold Pe0, the electric power stored in first battery B1 can be used up.

(5) In the vehicle V equipped with the power supply system 1, the driving by the drive motor M can be continued until the electric power stored in the first battery B1 is used up.

(6) In vehicle V, when the first SOC is less than the lamp lighting threshold value and the first upper output limit P1_ lim is greater than the output threshold value Pe0, discharge of second battery B2 is prohibited. Therefore, the vehicle V cannot supply electric power in accordance with the driver's request to the drive motor M, and the driver may feel discomfort. On the other hand, when the first SOC is less than the lamp lighting threshold, the management ECU71 displays warning information about the state of the power supply system 1 on the monitor 92. This can reduce the discomfort felt by the driver.

(7) In the vehicle V, the management ECU71 displays, on the monitor 92, information indicating that the state of the electric power output to the drive motor M is currently restricted, and main information for prompting the prompt charging of the first battery B1. According to the vehicle V, the sense of discomfort of the driver at the time of the output restriction of the drive motor M can be reduced, and the charging of the first battery B1 can be prompted.

While one embodiment of the present invention has been described above, the present invention is not limited to this. The structure of the detailed portion may be appropriately changed within the scope of the present invention.

For example, in the above embodiment, a case will be described in which when the first SOC is equal to or less than the lamp lighting threshold and the first upper output limit P1_ lim is greater than the output threshold Pe0, the converter passing electric power upper limit Pcnv _ max is set to 0, and the discharge of the second battery B2 is prohibited (see S27 in fig. 4); the invention is not so limited. When the first SOC is equal to or less than the lamp lighting threshold and the first output upper limit P1_ lim is greater than the output threshold Pe0, the inverter passing power upper limit Pcnv _ max may be made less than the second output upper limit P2_ lim, thereby limiting the discharge of the second battery B2 to less than the second output upper limit P2_ lim.

Reference numerals

V vehicle (electric vehicle)

W driving wheel

P pedal

L1 first reactor

L2 second reactor

B1 first accumulator (first accumulator)

B2 second accumulator (second accumulator)

M drive motor

1 power supply system

2 first power circuit

21p,21n first power line

22p positive pole contactor

22n negative electrode contactor

3 second power circuit

31p,31n second power line

32p positive electrode contactor

32n negative electrode contactor

33 Current sensor

4 load circuit (electric load)

41p,41n load power line

42 vehicle auxiliary machine

43 electric power converter

5 Voltage converter

53 connecting node

53H first high arm element

53L first Low arm element

54 connecting node

54H second high arm member

54L second Low arm element

55 negative bus

56p,56n low voltage side terminal

57p,57n high voltage side terminal

7 electronic control unit group (control device)

71 management ECU

72 motor ECU

73 inverter ECU

74 first Battery ECU (first remaining amount parameter acquiring means, first output Upper Limit acquiring means)

75 second accumulator ECU (second remaining amount parameter acquisition means)

81 first accumulator sensor Unit (first remaining quantity parameter acquisition means, first output Upper Limit acquisition means)

82 second accumulator sensor unit (second residual quantity parameter acquisition means)

91 charging demand lamp

92 monitor (information display device)

93 surplus running distance measuring meter