JPH05276603A - Residual capacity detector and charger for battery - Google Patents

Abstract

(57) [Summary] [Structure] The charge / discharge amount is obtained by the multiplier 7 from the charge / discharge current detected by the current detector 3. The charge / discharge amount is added / subtracted to / from the content of the remaining amount memory 8 by the adder / subtractor 9 to obtain the remaining capacity. At this time, when the charge / discharge current is equal to or higher than the rated current, the converter 5 corrects the charge / discharge current based on the capacity reduction characteristic peculiar to the storage battery 1 stored in the peculiar characteristic memory 4. [Effect] It becomes possible to detect the remaining amount with high accuracy in consideration of the loss of capacity at the time of large current. In particular, it is possible to accurately detect the remaining amount of a storage battery whose charge / discharge current fluctuates unpredictably, such as a storage battery of an electric vehicle. It is easy to optimize the capacity reduction characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage battery management technique mounted on, for example, an electric vehicle, and more particularly to a storage battery (secondary battery) capable of easily and accurately detecting the remaining battery level.

[0002]

2. Description of the Related Art An electric vehicle has a motor as a prime mover and a secondary battery (storage battery) as a power source of the motor. Therefore, unlike an internal combustion engine vehicle, it is necessary to charge a storage battery mounted on the vehicle instead of refueling fuel such as gasoline.
In order to popularize this electric vehicle, it is important to strengthen maintenance aspects such as enhancing charging facilities. From this point of view, research and improvement of, for example, a stand-type charger and other charging-related technologies are currently underway.

In order to properly charge the storage battery, it is essential to accurately grasp the remaining amount of the storage battery. Therefore, as described in, for example, Japanese Utility Model Laid-Open No. 3-34601, by devising the level of the storage battery by displaying the terminal voltage of the storage battery while changing the level during running or charging, it is possible to easily grasp the remaining amount of the storage battery. There is.

[0004]

Generally, in a storage battery, when the charge / discharge current is large, the capacity is reduced (loss), and the capacity reducing characteristic varies depending on the type of the storage battery. In particular, in the case of a storage battery used as a prime mover power source of an electric vehicle, a large current is discharged at the time of sudden acceleration, resulting in a large loss, and the frequency of sudden acceleration depends on environmental factors such as a driver's habit. Regarding charging, it is necessary to consider not only the normal charging method but also the rapid charging method. For this reason, even if the discharge amount or the charge amount is measured, it is difficult to detect the actual capacity change amount from those values.

Japanese Patent Laid-Open No. 3-17966 discloses that data such as the history of the storage battery is recorded in time series and this data is used for management of the storage battery.
However, as described above, there are various factors for changing the actual amount of change in the storage battery, and the inference of the remaining capacity tends to involve a complicated calculation. Considering application to a stand-type charger, it is a practical point to establish a calculation method for inferring the remaining capacity and the like easily and accurately.

In view of the above problems, the present invention provides a charging technique for electric vehicles such as a stand type charger,
It is an object of the present invention to provide a device for easily and accurately grasping the remaining amount of a storage battery.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the invention of claim 1 provides a storage battery remaining amount detecting device comprising the following elements.

(1) A current detector for detecting the charging / discharging current of the storage battery.

(2) A capacity reduction rate storage section for storing the capacity reduction rate of the storage battery with respect to the charge / discharge current.

(3) A charging / discharging current correcting section for correcting the charging / discharging current based on the capacity reduction rate.

(4) A charge / discharge amount calculation unit for obtaining the charge / discharge amount from the corrected charge / discharge current.

(5) A storage battery capacity storage unit for storing the capacity of the storage battery.

(6) A charge / discharge amount addition / subtraction unit for adding / subtracting the charge / discharge amount to / from the storage battery capacity.

According to a second aspect of the present invention, a battery charger mounted on an electric vehicle having an electric motor as a prime mover for charging a storage battery mounted as a power source of the electric motor is used. In a charging device provided with a charger operation circuit part to be controlled, the following means are taken.

(1) The electric vehicle has the following elements.

A) A detection unit for detecting the discharge amount of the storage battery.

B) A recording unit to which the detection output of this detection unit is supplied.

C) A memory card mounted on the recording unit, in which the output of the detection unit and the number of times of charging / discharging are written, and the drive information of the electric motor is written in advance.

D) A driving start switch which is connected to the recording section and is in a driving start state only when the memory card is mounted in the recording section.

(2) At least one of the electric vehicle side and the main body side is provided with a card reader for reading the stored content of the memory card and transmitting it to the charger operating circuit section.

(3) The charger operation circuit section performs a control operation according to the stored contents of the memory card.

[0022]

According to the invention of claim 1, the current of the storage battery is constantly monitored, and the charge / discharge amount is obtained from the charge / discharge current. The storage battery capacity storage unit stores the capacity of the storage battery, and the current capacity is detected by adding or subtracting the charge / discharge amount to or from this capacity. Here, in calculating the charge / discharge amount, the accuracy is ensured by obtaining the charge / discharge amount (strictly speaking, the amount of change in capacity) in consideration of the characteristics of the storage battery. That is, the capacity reduction rate for the charge / discharge current of the installed storage battery is stored in advance in the capacity reduction rate storage unit, the charge / discharge current is corrected based on this capacity reduction rate, and the corrected charge / discharge current is used. To obtain the charge / discharge amount.

According to the second aspect of the invention, the discharge amount of the storage battery is detected by the detection unit and sent to the recording unit. Since the memory card is attached to the recording unit, the discharge amount is written in the memory card. Since the drive information is also written in advance in the memory card, the driving start switch is turned on and the drive signal is supplied to the prime mover only when the memory card is attached to the recording unit. Further, since the discharge amount is written in the memory card, if the memory card is read into the charger operation circuit section, the charger will charge the storage battery according to the discharge amount.

[0024]

Embodiments of the present invention will be described below.

FIG. 1 shows an outline of a storage battery remaining amount detecting apparatus according to an embodiment of the present invention. Reference numeral 1 is a storage battery mounted on an electric vehicle. The shunt 2 divides the charging / discharging current of the storage battery 1. The current detector 3 detects a charge / discharge current from the divided current. The peculiar characteristic memory 4 stores data indicating the peculiar characteristic of the storage battery 1 mounted on the electric vehicle. The converter 5 converts the current detected by the current detector 3 into a value based on the data in the characteristic memory 4 when the current exceeds the rating. 6 is a clock. The multiplier 7 calculates the charge / discharge amount (AH) from the charge / discharge current and time. The remaining memory 8 is
The remaining capacity of the storage battery (current capacity (AH)) is stored. The adder / subtractor 9 adds / subtracts the charge / discharge amount to / from the remaining amount. The remaining amount indicator 10 displays the capacity of the storage battery.

Next, the operation of this device will be described. In this embodiment, the current of the storage battery 1 is constantly monitored. The direction of the current is the direction shown by the solid line arrow at the time of discharging and the direction shown by the broken line arrow at the time of charging, so it is possible to determine which of the charging and discharging is from the direction of the current. The charge / discharge amount is obtained from the charge / discharge current by the multiplier 7. By adding / subtracting the charge / discharge amount thus obtained to / from the remaining amount stored in the remaining amount memory 8, it is possible to accurately detect the remaining amount by following the change in capacity due to charging / discharging. The detected remaining amount is, for example, the remaining amount display unit 1 installed at a position easily visible from the driver's seat.
Displayed by 0.

When the charging / discharging current is less than the rated current, the converter 5 outputs the detected current as it is to the subsequent stage, but when the charging / discharging current is more than the rated current, the converter 5 outputs the value based on the data of the characteristic memory 4. Convert. FIG. 2 shows the correspondence relationship between the detected current and the conversion value (output of the converter 5), FIG. 2A shows the conversion of the discharge current, and FIG. 2B shows the conversion of the charging current. Regarding the discharge current, the detected current I is converted into a converted value I ′ based on, for example, the equation (1). Here, η is the capacity reduction rate (%) at the current I.

I ′ = {100 / (100−η)} · I (1) For example, when a storage battery having a capacity of 100 AH is discharged at a current of 100 A (1 hour rate), the capacity is actually 60
When decreasing to AH, η = 40, so 100A →
Conversion of 167A is performed. That is, considering a case where a 100 AH storage battery is discharged at 100 A for 30 minutes, 100 A × 0.5 when conversion by the characteristic memory is not performed.
It is calculated that the discharge amount is H = 50 AH, but when converted by the characteristic memory, it is 167 A × 0.5 H = 83.
It is calculated as a discharge amount of 5 AH.

Similarly, with respect to the charging current, the detected current I is converted into a converted value I ', for example, based on the equation (2).

I ′ = {(100−η) / 100} · I (2) As an example, when a storage battery having a capacity of 100 AH is charged at a current of 400 A (1/4 hour rate), actual charging is performed. When the amount is 60 AH, η = 40, so 400 A →
240A conversion is performed. 40 AAH battery
Considering charging at 0A for 15 minutes, 400A x 0.25H = 1 if conversion by the characteristic memory is not performed.
Calculated as a charge amount of 00 AH, but 240 A x 0.25 H = 60 AH when converted by the characteristic memory
It is calculated as the charge amount of.

If the amount of discharge or the amount of charge is calculated using these conversion values, the amount of decrease in capacity obtained by adding the amount of loss of capacity to the amount of discharge or the amount of increase in actual capacity obtained by subtracting the amount of loss from the amount of charge can be obtained. A calculation result closer to the true value of the remaining capacity can be obtained. Moreover, the optimization of the function used for conversion is
This can be easily performed by changing the setting of the capacity reduction rate η.

Next, another embodiment of the present invention will be described.
In FIG. 2, 11 is a stand-type charging device, and this charging device 11 includes a charger 12 composed of a thyristor,
A controller 13 that controls the charging current and voltage output from the charger 12, a card reader 14 that reads the contents of a memory card, which will be described later, and the contents read by the card reader 14 are supplied to drive the charger 12 It is composed of a charger operation circuit unit 15 which is operated according to the contents.

Reference numeral 16 is an electric vehicle.
The schematic configuration of is as follows. Reference numeral 17 denotes a detection unit for detecting the charge amount, which is constructed by the charge amount calculation function in the above embodiment. The discharge amount of the storage battery 1 obtained from the detection unit 3 is supplied to the card type recorder 17. A memory card (not shown) is attached to the recorder 18, and the battery discharge amount is written in the memory card via the recorder 18.

On the memory card, an ON signal of a driving device, which will be described later, is written in advance, and a battery type, a charging current, and a voltage are written in advance. Reference numeral 19 denotes an operation start switch (key switch), which is connected to the card type recorder 18. The switch 19 is configured so that an ON signal is not supplied to the drive device 20 when no memory card is attached to the card type recorder 18. That is, the memory card is the card type recorder 1.
The electric vehicle 16 will not start unless it is mounted on the vehicle 8. Reference numeral 21 denotes a memory card reader. When a memory card is attached to the reader 21, when charging of the storage battery 1 is completed by a mechanism (not shown), the charging device 11 is connected to the electric vehicle 16 for charging. Cable 2
The memory card cannot be taken out from the reader 21 unless 2 is removed.

The charging cable 22 is provided with a pair of lines 22a, 22b through which a charging current flows and a control line 22c for sending the contents of the discharge amount read by the card reader 21 to the charger operating circuit section 15 of the charging device 11. Has been.

Next, the operation of the above embodiment will be described. Charger 1
1 and the electric vehicle 16 are connected by a charging cable 22 so that the storage battery 1 can be charged. Next, the memory card (not shown) attached to the card recorder 18 is pulled out and the card is attached to the card reader 21 from the arrow B in the figure. The card reader 21 reads the contents (battery discharge amount) of the mounted memory card and supplies the contents to the charger operation circuit unit 15 of the charging device 11 via the control line 22c. Charger operation circuit section 1
Reference numeral 5 controls the controller 13 according to the contents of the input memory card. The controller 13 controls the charger 12 and supplies the charging current and voltage output from the charger 12 to the storage battery 1. This charging is performed according to the contents written in the memory card.

In the above embodiment, the memory card reader 21 is provided on the electric vehicle 16 side. However, when the card reader 21 is not attached to the electric vehicle 16 side, the card of the charging device 11 is provided. By mounting the memory card on the reader 14 in the direction of arrow A in the figure, the same charging operation as described above can be performed. In addition, since the number of times of charging / discharging is written in advance in the memory card, the life of the battery can be estimated by reading the number of times during charging.

[0038]

As described above, according to the storage battery remaining amount detecting apparatus of the present invention, the capacity reduction characteristic at the time of charging / discharging of the storage battery is stored in advance, and the charging / discharging current is calculated based on this characteristic. Since the amount of charge and discharge is determined after correction, even if the charge and discharge current fluctuates significantly,
It becomes possible to accurately detect the remaining amount in consideration of the loss at the time of large current. Therefore, it is possible to accurately detect the remaining amount even in a storage battery of an electric vehicle for which it is difficult to predict the charging / discharging current, and it is possible to accurately determine whether charging is required.

As described above, according to the present invention, it is possible to prevent the electric vehicle from starting while charging the battery of the electric vehicle to enhance safety during charging and to charge the battery according to the amount of discharge of the battery. In addition, the battery life can be estimated.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a storage battery remaining amount detection apparatus according to an embodiment of the present invention.

FIG. 2 is a graph showing conversion of detected current.

FIG. 3 is a block diagram showing an outline of a charging device according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Storage battery, 2 ... Shunt, 3 ... Current detector, 4 ... Inherent characteristic memory, 5 ... Converter, 7 ... Multiplier, 8 ... Adder / subtractor, 9
... remaining amount memory, 10 ... remaining amount display unit, 11 ... charging device, 1
2 ... charger, 13 ... controller, 14 ... card reader, 15 ... charger driving circuit section, 16 ... electric vehicle, 1
7 ... Detection part, 18 ... Card type recorder, 19 ... Operation start switch, 20 ... Driving device, 21 ... Card reader,
22 ... Cable for charging.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taiji Shibuya, 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Stock company company Meidensha (72) Inventor Hideaki Horie 2 Takaracho, Kanagawa-ku, Kanagawa Prefecture Nissan Motor Co., Ltd. Within

Claims (2)

[Claims] 1. A current detection unit that detects a charge / discharge current of a storage battery, a characteristic storage unit that stores a capacity change characteristic of the storage battery with respect to the charge / discharge current, and a charge / discharge that corrects the charge / discharge current based on the capacity change characteristic. A current correction unit, a charge / discharge amount calculation unit that calculates the charge / discharge amount from the corrected charge / discharge current, a storage battery capacity storage unit that stores the capacity of the storage battery, and a charge / discharge amount addition / subtraction that adds or subtracts the charge / discharge amount to / from the storage battery capacity. And a storage battery remaining amount detecting device. 2. A storage battery mounted as an electric power source of the electric motor in an electric vehicle having an electric motor as a prime mover is charged.
In a device including a charger that converts power source power and outputs direct current, and a charger operation circuit unit that controls the charger, a detection unit that detects the discharge amount of the storage battery on the electric vehicle side, and the detection unit Connected to the recording unit, a recording unit to which the detection output of the unit is supplied, a memory card attached to the recording unit in which the output of the detecting unit and the number of times of charging / discharging are written, and driving information of the electric motor is written in advance. And a driving start switch that is in a driving start state only when the memory card is mounted in the recording unit, and reads the stored contents of the memory card into at least one of the electric vehicle side and the main body side to perform the charging. A card reader for transmitting to a charger operation circuit unit, wherein the charger operation circuit unit performs a control operation according to the stored contents of the memory card. Charging apparatus according to symptoms.