JPH0654402A - Fuel gauge for electric vehicles - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fuel gauge of an electric vehicle that can accurately know the remaining amount of a battery mounted in the electric vehicle. [Composition] A bidirectional watt-hour meter (14) for detecting the power capacity of a battery (11) mounted on an electric vehicle, and the battery
Storage medium recording unique information and background information related to (11)
A means (18) for reading the correction information of the power capacity from (17), and a correction power capacity is calculated from the power capacity detected by the bidirectional watt-hour meter (14) and the correction information obtained by the reading means (18). And a display meter (16) for displaying the corrected power capacity calculated by the calculating means (19).

Description

Detailed Description of the Invention [Industrial applications]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle fuel gauge for displaying the remaining amount of a battery mounted in an electric vehicle.

[0002]

2. Description of the Related Art In recent years, electric vehicles equipped with batteries and powered by electricity have been attracting attention due to environmental problems and energy problems linked to them, and their active introduction is being considered. In the future, it is conceivable that an electric vehicle having a running capacity almost equal to that of a normal gasoline vehicle will be developed and widely spread.

Various batteries have been used as batteries for electric vehicles, and lead batteries, nickel-cadmium batteries, nickel-zinc batteries, sodium-sulfur batteries, etc. are known as typical ones. There is.

[0004]

Conventionally, in order to know the remaining amount of the battery mounted on such an electric vehicle, the terminal voltage has been used as a standard. However, the actual remaining amount varies depending on the type of battery, charge / discharge history, etc., and if you simply use the terminal voltage as a guideline, you will not be able to know the exact remaining amount, and output power will be insufficient during driving. was there. Also,
If the service station equipped with the charging equipment for electric vehicles is not adequately maintained, it is not possible to recharge anywhere when the battery level is low,
Further, since it takes time to charge the battery, there is a concern that the output power will be insufficient during traveling unless the accurate remaining amount is known in advance. That is, the remaining amount varies depending on the type of battery, the number of times of charging / discharging, the charging / discharging depth, the temperature during charging / discharging, the battery deterioration characteristics such as the self-discharge rate and the charging / discharging rate, and the specific gravity of the battery liquid, and the amount of power that can be used I needed to know the remaining amount.

Therefore, it is an object of the present invention to provide a fuel gauge for an electric vehicle, which can accurately know the remaining amount of a battery mounted on the electric vehicle.

[0006]

In order to achieve the above object, a fuel gauge for an electric vehicle according to the present invention relates to a bidirectional energy meter for detecting the power capacity of a battery mounted on the electric vehicle and the battery. Means for reading power capacity correction information from a storage medium recording unique information and history information, and calculation for calculating the corrected power capacity from the power capacity detected by the bidirectional watt-hour meter and the correction information obtained by the reading means. And a display for displaying the corrected power capacity calculated by the calculating means.

[0007]

According to the present invention, the electric power detected by the bidirectional watt-hour meter and the correction information obtained by the reading means from the storage medium in which the unique information and the history information about the battery are recorded are read about the type of the battery and the past charge / discharge. By calculating the information and the information by the calculating means and displaying the corrected remaining amount on the indicator, it is possible to know the remaining amount of power that can be effectively used according to the type of battery, usage history, charging conditions, etc. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in the drawings. FIG. 1 is a diagram illustrating a schematic configuration of a fuel gauge of an electric vehicle according to an embodiment of the present invention.

In FIG. 1, a fuel gauge for an electric vehicle according to this embodiment is located between a battery 11 mounted on the electric vehicle and the battery 11, the charger 12, and a driving motor 13 to detect electric power. A directional power meter 14, a battery capacity calculator 15 for performing a display process by correcting the power detected by the bidirectional power meter 14, and a display for displaying the power corrected by the battery capacity calculator 15. It is composed of 16 in total. The battery capacity calculation unit 15 reads the recording medium 17 in which the peculiar information and history information about the battery 11 are recorded in advance by the reading unit 18, and corrects the electric power detected by the bidirectional watt-hour meter 14 by the calculation unit 19. Is to do.

FIG. 2 is a diagram for explaining the structure of the fuel gauge of the electric vehicle according to the embodiment of the present invention. The parts corresponding to those in FIG. 1 are designated by the same reference numerals.

In FIG. 1, the capacity of the battery 11 mounted on the electric vehicle is supplied to the motor 13 arranged to drive the rear wheel 21 side via the bidirectional watt-hour meter 14 and also during deceleration or the like. Motor 13 driven by rear wheels 21
The electric power generated in 1 is returned as charging power for the battery 11 via the bidirectional watt-hour meter 14. Further, the power from the charger 12 is supplied to the battery 11 via the bidirectional watt-hour meter 14 by connecting the cable 22 to the outlet 23 that serves as a power supply port of the electric vehicle. The power detected by the bidirectional watt-hour meter 14 is corrected by a battery capacity calculator 15 having an electronic control unit for controlling the display operation of the fuel gauge, and the corrected power is displayed on the display 16. Is displayed.

FIG. 3 is a diagram for explaining the structure of the fuel gauge of the embodiment of the present invention in more detail. The parts corresponding to those in FIG. 1 are designated by the same reference numerals.

In FIG. 1, a battery 11 mounted on an electric vehicle includes a battery charger 12 and a bidirectional watt-hour meter 14.
The electric power of the battery 11 is supplied to the driving motor 13 via the bidirectional watt-hour meter 14. The bidirectional power meter 14 detects the power of the battery 11. The electric power detected by the bidirectional watt-hour meter 14 is corrected by the battery capacity calculation unit 15, and the corrected electric power is displayed on the display 16.

In the battery capacity calculation unit 15, the IC card 31 in which information unique to the battery such as the type of the battery 11 mounted in the electric vehicle in advance and the history information of the battery that has been used is recorded in the reader / reader. The data is read by the writer 32 and recorded in the storage device 34 or the like under the control of the central control device 33. The electric power detected by the bidirectional watt-hour meter 14 is recorded in the storage device 34 or the like under the control of the central processing unit 33. The central processing unit 33 performs correction processing on the electric power detected by the bidirectional watt-hour meter 14 based on the correction information read by the reader / writer 32 based on a predetermined computer program recorded in the storage device 34 or the like. To do. This corrected electric power is used by the indicator drive unit 3
At 6, for example, the digital data is converted into analog data or the like, and the converted data is given to the display meter 16 for display.

A calculation example of the correction processing by the battery capacity calculation unit 15 will be described. For example, as shown in FIG.
As for temperature characteristics, -1 for nickel-cadmium batteries
It is known that the capacity reduction rate at 0 ° C. is less than 10%, but that of a lead battery reaches about 25%. Also, FIG.
As shown in Fig. 5, when the nickel-cadmium battery is left for 30 days with the 5-hour rate capacity when left unattended as 100%, the capacity decreases to about 80%, but with the lead battery, the capacity exceeds 90%. Is known to remain. Further, as for the life, in the nickel-cadmium battery, as shown in FIG. 6, it is possible to charge and discharge about 1600 cycles before the capacity decreases to 80%, but in the lead battery, as shown in FIG. , About 600 cycles. Further, as shown in FIG. 8, the rapid discharge that consumes a large current in a short time such as when the vehicle suddenly starts or climbs a hill may have a large difference in the power that can be extracted depending on the discharge time depending on the type of battery. Therefore, the IC card 31 is preliminarily recorded with battery-specific information such as the type of battery, temperature characteristics, self-discharge characteristics, discharge depth, charge / discharge cycle, discharge rate characteristics, etc. , Such information is read at the time of charging and the electric power detected by the bidirectional watt-hour meter 14 is corrected by the central processing unit 33 by calculation based on a certain program.

In the fuel gauge of the electric vehicle having the above-described structure, the reader / writer 32 uses the IC card 31 in which the power of the battery 11 detected by the bidirectional watt-hour meter 14 is previously recorded with the unique information and the history information about the battery 11. Based on the read information, the electric power corrected by the constant calculation procedure stored in the storage device 34 is calculated, so that the battery 1
The remaining amount of 1 can be accurately known.

In the above embodiment, the IC card 3
Although the example in which the information about the battery 11 is recorded by using 1 has been described, a magnetic recording medium may be used as long as it is a recording medium that can be mounted in a vehicle and can record information.

Further, the arithmetic processing of the above embodiment is an example, and can be arbitrarily performed according to the characteristics of the battery 11, usage condition, etc., and is not limited to the embodiment.

[0019]

As described above, according to the present invention, the type of the battery and the past charging / discharging from the storage medium in which the electric power detected by the bidirectional watt-hour meter, the specific information about the battery and the history information are recorded. The correction information obtained by the reading means is calculated by the calculating means to obtain the corrected remaining amount, and the remaining amount is displayed on the display so that the battery can be used according to the type of battery, history of use, charging conditions, etc. There is an effect that the corrected effective remaining amount can be known.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a fuel gauge of an electric vehicle according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a fuel gauge of an electric vehicle according to an embodiment of the present invention.

FIG. 3 is a diagram for explaining the configuration of the fuel gauge of the embodiment of the present invention in more detail.

FIG. 4 is a diagram comparing temperature characteristics according to battery types.

FIG. 5 is a diagram comparing self-discharge characteristics according to battery types.

FIG. 6 is a diagram showing the service life of a nickel-cadmium battery.

FIG. 7 is a diagram showing the life of a lead battery.

FIG. 8 is a diagram showing discharge rate characteristics according to the type of battery.

[Explanation of symbols]

 11 Battery 12 Charger 13 Motor 14 Bidirectional Electric Energy Meter 15 Battery Capacity Calculation Unit 16 Display Meter 17 Storage Medium 18 Reading Means 19 Computing Means

Claims (1)

[Claims] 1. A bidirectional watt-hour meter for detecting the power capacity of a battery mounted on an electric vehicle, a means for reading correction information of the power capacity from a storage medium recording unique information and history information on the battery, and both. An electric vehicle equipped with a computing unit that calculates a corrected power amount from the power amount detected by the directional power meter and the correction information obtained by the reading unit, and an indicator that displays the corrected power amount calculated by the computing unit. Fuel gauge.