JPH08126104A - Battery control system of electric automobile - Google Patents

Abstract

PURPOSE: To provide a battery control system for an electric automobile, which can monitor the state of a battery for running when a key switch is off suppressing the current. CONSTITUTION: When the base voltage of a switch element 16 is at a high level under the off-state of a key switch, the switch element 16 is turned off with an RTC 13. The power feeding from an auxiliary battery 8 to a CPU 14, an A/D converter 15 and a sensor group 11 is stopped. When the base voltage of the switch element 16 becomes the low level for the time of T2, the base voltage of the switch element 16 is turned on by the RTC 13 for the T1 period of one minute or one hour. The CPU 14, the A/D converter 15 and the sensor group 11 are operated, and the state of a high-voltage battery 4 is computed by the CPU 14 and stored into a memory element 12. The battery state stored in the memory element 12 is outputted to a vehicle control unit 9 through a battery-state output means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery management system for an electric vehicle that detects the state of a running battery and monitors the running battery.

[0002]

2. Description of the Related Art In an electric vehicle which is being developed in recent years, it is important to accurately grasp the state of a running battery mounted on the vehicle. Therefore, various battery management systems have been proposed. .

For example, in Japanese Unexamined Patent Publication (Kokai) No. 5-227603, a signal from a vehicle sensor that detects information about a vehicle such as a starting operation state of an electric vehicle, a charging state such as a charging time and a charging amount, a charging frequency, and the like A signal from a battery sensor that detects information about the battery during operation is recorded in an IC card, and the signal is read when necessary, and the amount of charge, etc. is displayed for the driver, and the onboard battery There has been proposed a battery management system capable of efficiently performing charging.

Further, in Japanese Patent Laid-Open No. 6-54402,
A bidirectional watt-hour meter that detects the power capacity of the battery installed in an electric vehicle, a means that reads correction information of the power capacity from a storage medium that records unique information and history information about the battery, and a bidirectional watt-hour meter that detects the power capacity correction information. There is shown a battery management system that includes a calculation unit that calculates a corrected power capacity from the power capacity and correction information obtained by the reading unit, and that accurately determines the remaining battery level.

[0005]

By the way, such a battery management system stores the battery for traveling not only when traveling but also when the key switch is off, that is, when parking at night or storing for a long time. It is necessary to measure the temperature and the standing time to obtain a correction value for the remaining capacity of the running battery.

However, if the current consumption of the battery management system is large when the key switch of the electric vehicle is off, the battery may run out.

The present invention has been made in view of the above circumstances, and a battery management system for an electric vehicle capable of monitoring the state of the running battery when the key switch of the electric vehicle is off while suppressing current consumption. Is intended to provide.

[0008]

In order to achieve the above object, the battery management system for an electric vehicle according to the present invention as set forth in claim 1 is installed in an on-vehicle rechargeable battery and is driven by turning on a key switch. A plurality of battery state detecting means, a battery state calculating means for calculating the state of the traveling battery based on signals from the plurality of battery state detecting means when the key switch is turned on, and a battery calculated by the battery state calculating means. Battery state storage means for storing the state, and when the key switch is off,
The battery state calculating means and the plurality of battery state detecting means, a preset time every predetermined time,
It is provided with a timed operation means for supplying power to operate and a battery status output means for outputting the battery status stored in the battery status storage means to another control section.

According to a second aspect of the present invention, there is provided a battery management system for an electric vehicle, comprising a plurality of battery state detecting means arranged on a vehicle-mounted rechargeable battery for driving and driven by turning on a key switch, and the key. A battery state calculating means for calculating the state of the traveling battery based on signals from the plurality of battery state detecting means when the switch is turned on, and a battery state storing means for storing the battery state calculated by the battery state calculating means, When the key switch is off, the battery state calculating means and a part of the battery state detecting means of the plurality of battery state detecting means, a preset time every predetermined time,
It is provided with a timed operation means for supplying power to operate and a battery status output means for outputting the battery status stored in the battery status storage means to another control section.

Further, in the battery management system for an electric vehicle according to a third aspect of the present invention, a plurality of battery state detecting means disposed in a vehicle-mounted rechargeable battery for driving and driven by turning on a key switch, and the key. When the switch is turned on, the state of the running battery is calculated based on the signals from the plurality of battery state detecting means, and the battery state calculating means for outputting that the calculation processing of the running battery state is completed, and the battery. The battery state storage means for storing the battery state calculated by the state calculation means, the battery state calculation means and the plurality of battery state detection means are activated at predetermined time intervals when the key switch is off, and the battery state A timed operation means for supplying power to operate for a period of time until an output signal from the state calculation means is input; Battery status stored in Tteri state storage means in which and a battery status output means for outputting the other control unit.

According to a fourth aspect of the present invention, there is provided a battery management system for an electric vehicle according to a fourth aspect of the present invention, wherein the vehicle-mounted rechargeable battery for running is equipped with a key switch and the running battery is in a charged state. Driving a plurality of battery state detecting means, and when the key switch is on and the traveling battery is in a charging state, the state of the traveling battery is calculated based on signals from the plurality of battery state detecting means. Battery state calculation means, a battery state storage means for storing the battery state calculated by the battery state calculation means, and the battery state when the key switch is off and the traveling battery is not in the charging state. The calculating means and the plurality of battery state detecting means are operated by supplying power for a preset time every predetermined time. And scheduled actuating means that, in which a battery status output means for outputting the battery state stored in the battery state storage means to the other control unit.

[0012]

In the battery management system for an electric vehicle according to claim 1, when the key switch is turned off, the timed operation means stops the battery state calculation means which is stopped when the key switch is turned off and when the key switch is turned off. The plurality of battery state detecting means are operated by supplying power for a preset time every predetermined time. Then, the battery state calculating means calculates the state of the traveling battery based on the signals from the plurality of battery state detecting means arranged in the vehicle-mounted rechargeable traveling battery, and stores the state in the battery state storing means. It This battery state is output to another control unit by the battery state output means.

According to a second aspect of the battery management system for an electric vehicle of the present invention, when the key switch is turned off, the timed operation means stops the battery state calculation means to stop when the key switch is turned off, and the key switch is turned off. A part of the plurality of battery state detecting means stopped at 1 is operated by supplying power for a preset time every predetermined time. Then, the battery state calculating means determines the state of the traveling battery based on signals from some of the battery state detecting means of the plurality of battery state detecting means arranged in the vehicle-mounted rechargeable traveling battery. Is calculated and stored in the battery state storage means. This battery state is output to another control unit by the battery state output means.

Further, in the battery management system for an electric vehicle according to a third aspect of the present invention, when the key switch is turned off, the timed operation means stops the battery state calculation means and the key switch which are stopped when the key switch is turned off. The plurality of battery state detecting means to be stopped are activated at predetermined time intervals, and are operated by supplying power for the time until the output signal is input from the battery state calculating means. When the battery state calculating means and the plurality of battery state detecting means are activated, the battery state calculating means outputs a signal from the plurality of battery state detecting means arranged in the vehicle-mounted rechargeable battery for traveling. Based on this, the state of the battery for traveling is calculated, the battery state calculated by the battery state calculating means is stored in the battery state storage means, and the regular operation means that the calculation processing of the battery state for traveling is completed. Is output to the means, and the timed operation means stops the power supply to the battery state calculation means and the plurality of battery state detection means. The battery state stored in the battery state storage means is
It is output to another control unit by the battery state output means.

According to another aspect of the battery management system for an electric vehicle of the present invention, when the key switch is off and the traveling battery is not in a charging state, the key switch is off by the timed operation means, and , A battery state calculation means that is stopped when the traveling battery is not in a charging state, and a plurality of battery state detection means that is stopped when the traveling battery is not in a charging state when the key switch is off, It is operated by supplying power for a preset time every predetermined time. Then, the battery state calculating means calculates the state of the traveling battery based on the signals from the plurality of battery state detecting means arranged in the vehicle-mounted rechargeable traveling battery, and stores the state in the battery state storing means. It This battery state is output to another control unit by the battery state output means.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention, FIG. 1 is a wiring diagram for explaining a power supply system of a battery management system, and FIG.
Is a system configuration diagram mainly showing the power supply system of the electric vehicle, FIG.
FIG. 4 is an explanatory diagram of output waveforms from a real-time clock.

In FIG. 2, reference numeral 1 is a high voltage system of the power supply system of the electric vehicle, and reference numeral 2 is a low voltage system of the power supply system of the electric vehicle.

The high voltage system 1 is an external power source (not shown).
A driving motor 5 is connected to a high-voltage battery 4 having a charger 3 to be charged from a vehicle via a drive circuit 6 including an inverter, and a high-voltage electric load component 7a such as an air conditioner and a heater is connected. Is configured.

In the present embodiment, the high-voltage battery 4 is a lead battery, and 6 cells of 2.1V are used as a unit battery. Further, 28 unit batteries are connected in series to obtain a nominal 336V. Has been done. Then, as a plurality of battery state detecting means, a plurality of voltage sensors for detecting the terminal voltage for each unit battery or for each block of the plurality of unit batteries, a plurality of temperature sensors for detecting the temperature of each unit, and the high voltage A sensor group 11 including current sensors that detect the current of the battery 4 is provided.

The traveling motor 5 is an AC induction motor in this embodiment, and the traveling motor 5
Is transmitted to a drive system (not shown).

On the other hand, the low voltage system 2 is the high voltage system 1
The auxiliary battery 8 formed of a battery different from the above high-voltage battery 4 is used for a general electric component 7b such as a wiper or radio.
The vehicle control unit 9 and the battery management unit 10 of the battery management system are connected and mainly configured.

In the present embodiment, the auxiliary battery 8 is a battery different from the high voltage battery 4 and serves as a power source of 12 V (voltage for 6 cells).

Further, the vehicle control unit 9 receives a signal from the battery management unit 10, a signal from the drive circuit 6 or a signal from a sensor (not shown),
The state of the vehicle is obtained, the driver is provided with this information, and the vehicle is driven and other necessary control is performed based on the command from the driver.

Further, the battery management unit 10 is
The state of the high-voltage battery 4 is obtained based on the signal obtained from the sensor group 11 provided in the high-voltage battery 4, and the charging / monitoring control of the high-voltage battery 4 by the charger 3 is performed. The state of the high-voltage battery 4 is output to 9 and necessary battery management control (battery remaining amount measurement and the like) is performed based on a signal from the vehicle control unit 9.

Next, as shown in FIG. 1, the wiring of the power supply system of the battery management unit 10 and the sensor group 11 of the battery management system is such that the auxiliary battery 8 is connected to the memory element 12 as a battery state storage means. A CP that is connected to a real-time clock (RTC) 13 so as to be constantly supplied with power, and further includes a battery state calculation means.
The U14, the A / D converter 15 and the sensor group 11 are connected via a switching element 16 operated by the RTC 13. The CPU 14, the A / D converter 15 and the sensor group 11 are connected to the auxiliary battery 8 via a key switch 17.

Therefore, if either one of the switching element 16 and the key switch 17 is turned on, the CPU 14, the A / D converter 15 and the sensor group 1 are turned on.
1 is supplied with power from the auxiliary battery 8 and can be operated.

The memory element 12 is a ROM or SRAM.
In addition to being a storage part of the battery state calculated by the CPU 14, data such as a map table necessary for the operation of the CPU 14 is stored in advance.

Further, the CPU 14 detects each sensor of the sensor group 11 at every predetermined time, and detects the A / D converter 1
Based on the digital signal converted in 5, the high voltage battery 4
Is calculated and stored in the memory element 12, and the battery state stored in the memory element 12 is output to the vehicle control unit 9 via a battery state output means (not shown).

As shown in FIG. 3, the signal output from the RTC 13 is a low level voltage VL of T2 at every cycle T1.
Is an output signal that is generated, and in this embodiment,
T1 is set to one minute or one hour, and T2 is set to 0.1 second. In addition, the length of the time T2 is equal to the CPU
It is preset in consideration of the processing speed of 14, and T2 is shorter when the processing speed is fast, and T2 when the processing speed is slow.
2 is set longer. The RTC 13 works in conjunction with the key switch 17, and outputs the output signal described above when the key switch 17 is off.

The switching element 16 is a PNP.
With a transistor, the base of this transistor and the above RT
C13 is connected, and the RTC 13 causes the base voltage of the switching element 16 to have a high level VH.
Then, the switching element 16 is turned off, and when the base voltage of the switching element 16 becomes the low level VL, the switching element 16 is turned on. That is, the RTC 13 and the switching element 16 form a timed operation means.

Next, the operation of the above configuration will be described. First, in a state where the key switch 17 is turned on when an electric vehicle is running, etc., the CPU 14, the A / D converter 15, and the sensor group 11 are connected to the auxiliary battery as is apparent from the wiring diagram of FIG. Power is supplied from 8 to operate, and each sensor of the sensor group 11 detects the terminal voltage, temperature, and current of the high-voltage battery 4 at predetermined time intervals.

The signal from the sensor group 11 is
It is converted into a digital signal by the A / D converter 15, and based on this signal, the state of the high voltage battery 4 is changed to the CPU 1
4 and stored in the memory element 12,
The battery state stored in the memory element 12 is output to the vehicle control unit 9 via a battery state output means (not shown).

Next, when the electric vehicle is parked and the key switch 17 is off, the RTC 1
3, when the base voltage of the switching element 16 becomes the high level VH, the switching element 16 is turned off and the auxiliary battery 8 to the CPU 14, the A / D converter 15 and the sensor group 11 is turned on. The power supply from is stopped.

Then, with a period T1 of 1 minute or 1 hour,
When the base voltage of the switching element 16 is at the low level VL for the time T2 by the RTC 13, the switching element 16 is turned on and the CPU
14, the A / D converter 15 and the sensor group 11 are operated, and the signal from the sensor group 11 is converted into the A / D signal.
The converter 15 converts it into a digital signal, and based on this signal, the state of the high-voltage battery 4 is calculated by the CPU 14, stored in the memory element 12, and the battery state stored in the memory element 12 is stored in the vehicle. It is output to the control unit 9 via the battery state output means.

As described above, according to the first embodiment, when the key switch of the electric vehicle is off, it is possible to monitor the state of the high voltage battery, that is, the running battery while suppressing the current consumption.

Next, FIG. 4 shows a modification of the first embodiment. As shown in FIG. 4, the memory element 12 and the RTC 13 are connected so as to be operated by a rechargeable backup power source 21 different from the auxiliary battery 8. The backup power source 21 has a key switch 17 turned on. It is connected to the battery charger 22 so as to be charged at the time of. Therefore, when the key switch 17 is off, the state of the high voltage battery 4 can be monitored while further reducing the current consumption of the auxiliary battery 8.

Next, FIG. 5 is a wiring diagram for explaining the power supply system of the battery management system according to the second embodiment of the present invention. The second embodiment differs from the first embodiment in that the number of sensors used for measurement is reduced when the key switch is off.

That is, as shown in FIG.
1 that operates in advance at a predetermined time even when the key switch 17 is off like the voltage sensor and some temperature sensors, and when the key switch 17 is off like the current sensor and the remaining temperature sensors. Is separated from the element 11b that is completely stopped by a diode 25 so that the sensor group 11b does not operate even when the switching element 16 is periodically turned on when the key switch 17 is off. Has become. Therefore, the key switch 17
When is off, it is possible to monitor the state of the high voltage battery 4 while further suppressing the current consumption of the auxiliary battery 8.

Next, FIGS. 6 and 7 show a third embodiment of the present invention, FIG. 6 is a wiring diagram for explaining the power supply system of the battery management system, and FIG. 7 is a circuit component of the power supply system of the battery management system. It is a time chart explaining operation. In the third embodiment, the CPU when the key switch is off,
Power supply to the A / D converter and the sensor group is stopped by the CPU itself.

That is, as shown in FIG.
Is connected to the base of the NPN transistor 31, and this N
Collector of PN transistor 31 and switching element 1
6 bases are connected. The base of the NPN transistor 31 is connected to the thyristor 33 operated by the CPU 32.

In addition to the functions described in the first embodiment, the CPU 32 is
It has a function of outputting a signal to the thyristor 33.

Therefore, as shown in FIG. 7, when the RTC 13 outputs a signal from VH to VL while the key switch 17 is off (t1), the thyristor 33 is turned off and t
When the RTC13 becomes VH at t2 after 1 to T2, NP
The collector voltage of the N-transistor 31 is high level (V
From T1CH) to the low level (VT1CL), the switching element 16 is turned on, and power is supplied to the CPU 32, the A / D converter 15 and the sensor group 11.

When the CPU 32 completes the calculation and outputs a signal to the thyristor 33 (t3), the thyristor 33 is turned on and the NPN transistor 31 is turned on.
Collector voltage goes from low level (VT1CL) to high level (VT1CH), the switching element 16 is turned off, and power supply to the CPU 32, the A / D converter 15 and the sensor group 11 is stopped.

As described above, according to the third embodiment, when the key switch is off, power is supplied only for the time required for the arithmetic processing of the CPU, so that the state of the high voltage battery is monitored and the current consumption of the auxiliary battery is reduced. Can be further suppressed.

Next, FIG. 8 is a wiring diagram for explaining the power supply system of the battery management system according to the fourth embodiment of the present invention.
In the fourth embodiment, when the key switch is off, the high-voltage battery can be monitored when the key switch is on, as if the key switch was on.

That is, as shown in FIG. 8, the auxiliary battery 8, the CPU 14, the A / D converter 15 and the sensor group 1
1 is a relay 3 provided in parallel with the key switch 17.
5, the relay 35 is connected via a charging coupler 36 so as to be turned on / off by an external power source 37. Therefore, the key switch 17
Even when is off, during charging, the high voltage battery can be monitored as if the relay 35 was turned on by the external power source 37 and the key switch was turned on.

Next, FIG. 9 shows a modification of the fourth embodiment. Even when the key switch 17 is off, the high voltage battery can be monitored by the external power source 37 during charging. As shown in FIG.
Is connected to the CPU 14 and the A / D converter 1 via the charging coupler 36.
5 and the sensor group 11. Therefore, it becomes possible to monitor the state of the high-voltage battery, that is, the running battery while suppressing the current consumption of the auxiliary battery.

In each of the above embodiments, the example in which the traveling motor is an AC induction motor has been described, but the present invention is not limited to this, and the motor is an AC synchronous motor or a DC motor. May be.

In the present embodiment, the output from the real-time clock has been described by setting the period T1 to 1 minute or 1 hour and the low level time T2 to 0.1 second, but the present invention is not limited to this. Not a thing.

Further, in the above embodiments, the lead battery is explained, but the present invention can be applied to other batteries such as nickel cadmium, nickel-hydrogen, nickel-zinc, sodium-sulfur, zebra battery and lithium. .

[0051]

As described above, according to the present invention, it becomes possible to monitor the state of the running battery when the key switch of the electric vehicle is off while suppressing the current consumption.

[Brief description of drawings]

FIG. 1 is a wiring diagram illustrating a power supply system of a battery management system according to a first embodiment of the present invention.

FIG. 2 is a system configuration diagram mainly showing a power supply system of the electric vehicle according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of an output waveform from a real-time clock according to the first embodiment of the present invention.

FIG. 4 is a wiring diagram illustrating a power supply system of a battery management system according to a modification of the first embodiment of the present invention.

FIG. 5 is a wiring diagram illustrating a power supply system of a battery management system according to a second embodiment of the present invention.

FIG. 6 is a wiring diagram illustrating a power supply system of a battery management system according to a third embodiment of the present invention.

FIG. 7 is a time chart explaining the operation of the circuit components of the power supply system of the battery management system according to the third embodiment of the present invention.

FIG. 8 is a wiring diagram illustrating a power supply system of a battery management system according to a fourth embodiment of the present invention.

FIG. 9 is a wiring diagram illustrating a power supply system of a battery management system according to a modification of the fourth embodiment of the present invention.

[Explanation of symbols]

 4 High-voltage battery (battery for traveling) 8 Auxiliary battery 9 Vehicle control unit 10 Battery management unit 11 Sensor group (plurality of battery state detection means) 12 Memory element (battery state storage means) 13 Real-time clock (timed operation means) 14 CPU ( Battery state calculation means) 16 Switching element (timed operation means) 17 Key switch

Claims (4)

[Claims] 1. A plurality of battery state detecting means disposed in a vehicle-mounted rechargeable battery for driving and driven by turning on a key switch, and based on signals from the plurality of battery state detecting means when the key switch is turned on. Battery state calculating means for calculating the state of the traveling battery, battery state storing means for storing the battery state calculated by the battery state calculating means, and the battery state calculating means for storing the battery state when the key switch is off. A battery for outputting a battery state stored in the battery state storage means to another control section, and a timed operation means for operating the plurality of battery state detection means by supplying power for a preset time every predetermined time. A battery management system for an electric vehicle, comprising: a status output means. 2. A plurality of battery state detecting means disposed on a vehicle-mounted rechargeable battery for driving and driven when a key switch is turned on, and based on signals from the plurality of battery state detecting means when the key switch is turned on. Battery state calculating means for calculating the state of the traveling battery, battery state storing means for storing the battery state calculated by the battery state calculating means, and the battery state calculating means for storing the battery state when the key switch is off. A fixed time operating means for operating a part of the plurality of battery state detecting means by supplying power for a preset time every predetermined time, and a battery stored in the battery state storing means. A battery management system for an electric vehicle, comprising: a battery status output unit that outputs a status to another control unit. 3. A plurality of battery state detecting means disposed in a vehicle-mounted rechargeable battery for driving and driven by turning on a key switch, and based on signals from the plurality of battery state detecting means when the key switch is turned on. Battery state calculating means for calculating the state of the traveling battery and outputting that the traveling battery state calculating process is completed; and battery state storing means for storing the battery state calculated by the battery state calculating means. When the key switch is off, the battery state calculating means and the plurality of battery state detecting means are activated every predetermined time, and power is supplied until the output signal from the battery state calculating means is input. The timed operation means for operating the battery state and the bar for outputting the battery state stored in the battery state storage means to another control section. Battery management system for an electric vehicle characterized by comprising a terry state output means. 4. A plurality of battery state detecting means, which is disposed on a vehicle-mounted rechargeable battery for driving and has a key switch turned on and the battery for driving is charged, and the key switch is turned on. A battery state calculation means for calculating the state of the traveling battery based on signals from the plurality of battery state detection means when the traveling battery is in a charging state, and a battery calculated by the battery state calculation means. Battery state storage means for storing a state, and when the key switch is off and the traveling battery is not in a charged state, the battery state calculation means and the plurality of battery state detection means are provided at predetermined intervals. And a battery state stored in the battery state storage means, which is operated by supplying power for a preset time. Battery management system for an electric vehicle characterized by comprising a a battery status output means for outputting the other control unit.