JPH09171064A - Battery-abnormality warning apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a battery-abnormality warning apparatus in which the sum of absolute values of differences between detection signals to be input is found, by when, when the sum is at a prescribed value or higher, it is judged that an abnormal battery is contained in any battery block and which operates an abnormality alarm. SOLUTION: Regarding battery blocks 3, 7 in which batteries in a first number N are connected in series, their terminal voltages are detected by voltage sensors 1, 5. Regarding battery blocks 4, 8 in which batteris in a number M different from the first number N are connected in series, detection signals in which the number of batteries is converted into the first number N is obtained by battery-block equivalent-terminal-voltage detection means (17 and 2, 18 and 6) are obtained. In a battery abnormality judgment device 9, the sum of absolute values of differences between the detection signals is found. When the sum is at a prescribed value or higher, it is judged that an abnormal battery exists, and an abnormality alarm 10 is operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery block composed of a plurality of batteries connected in series,
The present invention relates to a battery abnormality alarm device that issues an alarm when there is a battery whose voltage is abnormally reduced by several power supplies connected in series or in parallel.

[0002]

2. Description of the Related Art In some cases, it is required to construct a high-voltage, large-capacity power supply with a battery rather than a commercial power supply. In such a case, a battery block in which a plurality of batteries are connected in series is used. , Some are connected in series or in parallel to form one power supply.

One such example is a power supply for powering a drive motor of an electric vehicle. Hereinafter, the case of the power source of the electric vehicle will be described as an example. In an electric vehicle, a high-voltage, large-capacity power source is required to drive a drive motor, and therefore many batteries are mounted. When mounting, it is necessary to consider restrictions in terms of installation space, weight balance, etc.
Several batteries connected in series are regarded as one battery block, and some of these battery blocks (for example, 4 to 6) are used.
They are placed here and there and are connected in series or in parallel as appropriate.

A battery is used for a long time by repeating charging and discharging, but it deteriorates or breaks down during use. If the battery deteriorates or fails, the same voltage as that of a normal battery cannot be maintained, so that the running performance of the electric vehicle is deteriorated or the energy of another battery is consumed. If a deteriorated or broken battery is left as it is, an electric system accident may be caused or, in the worst case, the vehicle may be unable to run.

Therefore, a battery abnormality alarm device has been considered, which detects a deterioration or failure of a battery and issues an alarm. Various characteristics of a deteriorated or failed battery (eg voltage characteristics)
Changes greatly compared to a normal one, so focus on that and detect. However, since the number of batteries mounted on an electric vehicle is large, detection is not performed for each individual battery, but detection is performed in battery block units and replacement is performed in battery block units.

FIG. 6 is a diagram showing a conventional battery abnormality alarm device used in an electric vehicle. In FIG. 6, 13 is a drive motor control device, 16 is a drive motor, 20 is an alarm circuit, 21 is a comparison logic circuit, 22 is a switching circuit, and 23 and 24 are battery blocks. Each battery block is made up of all n batteries.

Between the battery blocks 23 and 24,
Several battery blocks are connected in series. The drive motor control device 13 supplied with power from the battery blocks connected in series controls the drive motor 16 by a signal from an accelerator pedal sensor (not shown) or the like.

The voltage across the terminals of the battery blocks 23, 24 etc. is once input to the switching circuit 22. Switching circuit 2
2 sequentially switches them and inputs them to the comparison logic circuit 21. The comparison logic circuit 21 determines that there is an abnormality and sends a signal to the alarm circuit 20 when the input voltage itself is extremely low or is relatively significantly lower than the voltages of other battery blocks. In response to the signal, the alarm circuit 20 issues an alarm (lamp, buzzer, etc.).

As a conventional document relating to such a battery abnormality alarm device, for example, Japanese Patent Laid-Open No. 55-113277 is available.
There is an official gazette.

[0010]

[Problems to be solved by the invention]

(Problem) However, in the above-described conventional battery abnormality alarm device, since the voltages between the terminals are sequentially switched and compared with one reference value for determination, the number of batteries constituting the battery block is equal (all (n pieces) is assumed. Therefore, there is a problem that it cannot be applied when the numbers are not equal.

(Explanation of Problems) When a number of batteries are connected to form one power source, the sizes of the battery blocks cannot always be made equal due to restrictions on the space for arranging the power sources. Therefore, the number of batteries forming the battery block may be different. In such a case, the above-mentioned conventional technique cannot be applied.

Incidentally, when a battery for a drive motor is mounted on an electric vehicle, the size of the battery block may not be the same because it is necessary to consider the restrictions on the installation space and the weight balance. Often. An object of the present invention is to solve such a problem.

[0013]

In order to solve the above-mentioned problems, in the battery abnormality alarm device of the present invention, a voltage sensor for detecting the terminal voltage of a battery block composed of a first number of batteries connected in series is provided. , A battery block equivalent terminal for providing a battery block terminal voltage detection signal, which is attached to a battery block in which the number of batteries connected in series is different from the first number, and is proportionally distributed as the amount corresponding to the first number of batteries The difference between the voltage detection means and the detection signals from the voltage sensor and the battery block equivalent terminal voltage detection means is calculated, and when the sum of the absolute values of the differences is equal to or greater than a predetermined value, it is determined that the battery is abnormal. A battery abnormality determination device for determining and an abnormality alarm device operated by the battery abnormality determination device are provided.

The battery block equivalent terminal voltage detecting means includes a voltage converter for converting the terminal voltage of the battery block into the first number of batteries, and a voltage for detecting the voltage converted by the voltage converter. It can be configured with a sensor.

Alternatively, the battery block equivalent terminal voltage detecting means includes a voltage sensor for directly detecting the terminal voltage of the battery block, and a signal multiplication factor for making the detection signal from the voltage sensor a value for the first number of batteries. It can also be configured with a container.

(Outline of Operation to Be Solved) With respect to the battery block in which the first number of batteries are connected in series, the terminal voltage is directly detected by the voltage sensor. For a battery block in which a number of batteries different from the first number are connected in series, a battery block terminal voltage detection signal proportionally distributed by the battery block equivalent terminal voltage detection means as a portion corresponding to the first number of batteries. To get

These detection signals are input to the battery abnormality determination device. In the battery abnormality determination device, the sum of absolute values of the differences between the input detection signals is calculated, and the sum is a predetermined value or more. If there is, it is determined that an abnormal battery is included in some battery block, and the abnormality alarm device is activated.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. In each case, a battery abnormality alarm device for a battery power source of an electric vehicle is used as an example. (First Embodiment) FIG. 1 is a diagram showing a first embodiment of a battery abnormality warning device of the present invention. Reference numerals correspond to those in FIG. 6, 1 and 2 are voltage sensors, 3 and 4 are battery blocks, 5 and 6 are voltage sensors, 7 and 8 are battery blocks, 9 is a battery abnormality determination device, and 10 is an abnormality alarm device. 1
1 is a key switch, 12 is a sub battery, 14 is a selector lever switch, 15 is an accelerator pedal sensor, 17,
18 is a voltage converter.

In this example, it is assumed that there are two types of battery blocks, that is, the battery blocks 3 and 7 having N batteries and the battery blocks 4 and 8 having M batteries. A series connection body of N and M battery blocks is connected in parallel to form a main power supply. The voltage of this main power supply is applied to the drive motor control device 13.

The drive motor control device 13 is activated by turning on the key switch 11, and controls the drive motor 16 based on a shift command signal from the selector lever switch 14, an accelerator signal from the accelerator pedal sensor 15, and the like. The sub-battery 12 is a low-voltage (for example, 12V) power source for supplying power to the key switch 11 and a control circuit (not shown).

The voltage sensors 1 and 5 detect the voltages of the battery blocks 3 and 7 having N batteries, and input them to the battery abnormality determination device 9. The voltage sensors 2 and 6 detect the output voltages of the voltage converters 17 and 18 and input them to the battery abnormality determination device 9. The voltage converters 17 and 18 convert the voltages of the battery blocks 4 and 8 having M batteries into the number of batteries of the other type battery blocks 3 and 7 (N
It is a means of converting the voltage into the number of pieces. The voltage converter may be provided for the battery blocks 3 and 7 (however, in that case, a means for converting the voltage into the number of batteries M) is used.

The reason why the voltage converters 17 and 18 convert the voltages from the battery blocks having different numbers of batteries into the voltages of the same number of batteries (N) is that the detection signals input to the battery abnormality determination device 9 are the same. This is because the detection signal is equivalent to the number of batteries. Therefore,
The voltage sensor 2 and the voltage converter 17 constitute a battery block equivalent terminal voltage detecting means for obtaining a detection signal equivalent to the detection signal from the voltage sensor 1. Similarly, the voltage sensor 6 and the voltage converter 18 also constitute a battery block equivalent terminal voltage detecting means. By these means,
The detection signals input to the battery abnormality determination device 9 are all signals corresponding to battery blocks having N batteries, and are equivalent.

The battery abnormality determination device 9 determines whether or not there is an abnormal battery block based on the detection signals input from the respective voltage sensors, and if there is, the abnormality alarm device 10 Is activated (turned on). Abnormal alarm 1
As 0, for example, a lamp or a buzzer is used. Since the battery abnormality determination device 9 performs signal calculation and logic determination as described below, it can be configured by, for example, a simple computer. The activation of the battery abnormality determination device 9 is also performed by turning on the key switch 11.

FIG. 3 is a flow chart for explaining the operation of the battery abnormality judging device 9. Step 1 ... Read the detection signal from each voltage sensor.
This detection signal indicates the battery block voltage, but has a value obtained by converting the voltage of each battery block into the same number of batteries.

Step 2 ... Calculate the difference (ΔV) in the detected battery block voltage. Voltage sensors 1, 2, 5, 6
In the detected battery block voltages, V _1, respectively, V
_{When 2} , V ₅ and V ₆ are set, for example, the following difference is calculated. ΔV ₁₂ = V ₁ −V ₂ , ΔV ₂₅ = V ₂ −V ₅ ΔV ₅₆ = V ₅ −V ₆ , ΔV ₆₁ = V ₆ −V ₁

If the battery block 3 contains a deteriorated or defective battery, the battery block voltage V ₁ is equal to the other battery block voltages V ₂ , V ₂ .
_Since it is smaller than ₅ and V ₆ , the absolute values of ΔV ₁₂ and ΔV ₆₁ are large. If all batteries are normal, there is not much difference in the detected battery block voltage,
The absolute values of ΔV ₁₂ , ΔV ₂₅ , ΔV ₅₆ , and ΔV ₆₁ are all small values. The reason for calculating the difference (ΔV) in the battery block voltage in this step 2 is that if there is a deteriorated or defective battery, the difference (ΔV) related to that battery is
This is because the change that V) becomes large appears.

Step 3 ... The sum (ΣΔV) of the absolute values of the voltage difference is calculated. ΣΔV = | ΔV ₁₂ | + | ΔV ₂₅ | + | ΔV ₅₆ | + | ΔV
₆₁ | Step 4 ... Check whether the above sum is smaller than a set value (K). When a battery that has deteriorated or has failed is included in the set value K, the magnitude of the sum is obtained in advance by experiments or the like, and is set as a guide. To do.

Step 5: If the value is smaller than the set value K, the battery is normal, so the abnormality alarm device 10 is kept off. Step 6 ... If the value is equal to or more than the set value K, the abnormal alarm device 10 is turned on because any of the battery blocks includes an abnormal battery. This allows the driver to know that the battery is abnormal.

Although the battery block voltage difference is calculated in step 2, the calculation method is not limited to that described above, and the following calculation may be performed. ΔV ₁₂ = V ₁ −V ₂ ΔV ₂₅ = V ₂ −V ₅ ΔV ₅₆ = V ₅ −V ₆ ΔV ₁₅ = V ₁ −V ₅ ΔV ₂₆ = V ₂ −V ₆ ΔV ₁₆ = V ₁ −V ₆ This is because, even if the difference is taken, if there is a battery that is deteriorated or malfunctions, the difference (ΔV) related to the battery also changes.

Further, instead of checking each of the differences of the detection signals, the sum of the absolute values of the differences is obtained to obtain one set value K.
The reason for comparing with is to simplify the determination process.

FIG. 2 is a diagram showing a specific example of the voltage converter 17, and the reference numerals correspond to those in FIG. The voltage converter 17 calculates the voltage across the battery block 4 (N / M).
It can be composed of a voltage divider circuit (for N
<M).

Although the battery block equivalent terminal voltage detecting means of FIG. 1 is composed of a voltage sensor and a voltage converter connected to the input side thereof, a signal multiplier is connected to the output side of the voltage sensor. You may comprise. FIG. 4 is a diagram showing a battery block equivalent terminal voltage detecting means configured by connecting a signal multiplier to the output side of the voltage sensor. Reference numerals correspond to those in FIG. 1, and 19 is a signal multiplier. After the voltage of the battery block 3 having N batteries is detected by the voltage sensor 1, the detection signal is detected by the signal multiplier 19
Amplify (M / N) times. On the other hand, if the number of batteries is M
The voltage of the individual battery block 4 remains detected by the voltage sensor 2. With this configuration, at the stage of being input to the battery abnormality determination device 9, all detection signals are equivalent to detection signals for the number M of batteries.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
2 is a diagram showing an embodiment of the present invention, and reference numerals correspond to those in FIG. Portions with the same reference numerals have the same configuration and operate in the same manner, and therefore their explanations are omitted. The configuration is different from the first embodiment in that the number of batteries constituting the battery block is all equal (N). In this case, since the number of batteries is the same, the battery block equivalent terminal voltage detecting means is unnecessary.

This embodiment shows that the present invention can be applied even when the number of batteries in the battery block is all equal. The detection signal from each voltage sensor is originally equivalent to N battery blocks having the same number of batteries. Therefore, it is directly input to the battery abnormality determination device 9 and processed according to the flowchart shown in FIG.

Although the battery block equivalent terminal voltage detecting means is not shown in FIG. 5, a battery block equivalent terminal including a voltage converter or a signal multiplier is provided for a general case where the number of batteries may be different. The voltage detection means may be connected, and the voltage division ratio or the multiplication factor may be set to "1" when it happens that the numbers are the same.

If at least one abnormal battery is included in the battery block, the battery block is replaced.

[0037]

As described above, according to the battery abnormality alarm device of the present invention, even if the number of batteries constituting the battery block is different, the same number of batteries can be obtained by the action of the battery block equivalent terminal voltage detecting means. Since the converted detection signal is obtained to determine whether or not there is an abnormality, it can be applied even when the number of batteries constituting the battery block is different.

In processing the terminal voltage detection signal of the battery block, the sum of the absolute values of the differences between the detection signals is simply obtained and it is checked whether the sum is a predetermined value or more. Only one is required, and the calculation is easy.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a specific example of a voltage converter.

FIG. 3 is a flowchart illustrating the operation of the battery abnormality determination device.

FIG. 4 is a diagram showing another battery block equivalent terminal voltage detecting means.

FIG. 5 is a diagram showing a second embodiment of the present invention.

FIG. 6 is a diagram showing a conventional battery abnormality alarm device used in an electric vehicle.

[Explanation of symbols]

1, 2 ... Voltage sensor, 3, 4 ... Battery block, 5,
6 ... Voltage sensor, 7, 8 ... Battery block, 9 ... Battery abnormality determination device, 10 ... Abnormality alarm device, 11 ... Key switch, 12 ... Sub battery, 13 ... Driving motor control device, 14 ... Selector lever switch, 15 ... accelerator pedal sensor, 16 ... drive motor, 17, 18 ... voltage converter, 19 ... signal multiplier, 20 ... alarm circuit, 21 ... comparison logic circuit, 22 ... switching circuit, 23, 24 ... battery block

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01M 10/48 H01M 10/48 P

Claims (3)

[Claims] 1. A voltage sensor for detecting a terminal voltage of a battery block composed of a first number of batteries connected in series, and a battery block in which the number of batteries connected in series is different from the first number. , A battery block equivalent terminal voltage detection means for obtaining a battery block terminal voltage detection signal proportionally distributed as a portion corresponding to the first number of batteries, and detection from the voltage sensor and the battery block equivalent terminal voltage detection means A battery abnormality determination device that calculates the difference between signals and determines that the battery is abnormal when the sum of the absolute values of the differences is greater than or equal to a predetermined value, and an abnormality alarm device that is activated by the battery abnormality determination device. A battery abnormality alarm device characterized by comprising: 2. A voltage converter for converting the terminal voltage of the battery block into the first number of batteries for the battery block equivalent terminal voltage detecting means, and a voltage for detecting the voltage converted by the voltage converter. The battery abnormality alarm device according to claim 1, wherein the battery abnormality alarm device comprises a sensor. 3. The battery block equivalent terminal voltage detecting means, a voltage sensor for directly detecting the terminal voltage of the battery block, and a signal multiplication factor for making a detection signal from the voltage sensor a value corresponding to the first number of batteries. The battery abnormality alarm device according to claim 1, wherein the battery abnormality alarm device is configured with a battery.