JPH08186939A - Power supply - Google Patents

Abstract

PURPOSE: To judge the deteriorating state of a storage battery without the effect on a load by providing the storage battery, which is charged by a float charging method or a trickle charging method, and forcibly decreasing the output voltage of the storage battery to an arbitrary value between the super power of the storage battery itself and the minimum allowable operating voltage of a load apparatus. CONSTITUTION: A storage battery 2 and a load 3 are connected to a charging device 1 in parallel. The charging device 1 uses a commercial power source as the input power source. The voltage is converted into the optimum floating voltage for the storage battery 2, and the electric energy is supplied into the storage battery 2 and the load 3. For judging the deteriorating state of the storage battery 2, the output voltage of the charging device 1 is forcibly decreased to an arbitrary value between the electromotive force of the storage battery 2 itself and the minimum allowable operating voltage of the load 3. At this time, the output voltage of the charging device 1 is lower than the discharging voltage of the storage battery 3, and the discharging is started from the storage battery 2. The difference between the discharging voltage when a test is discontinued and the standard voltage at the time of theoritical discharging capacity corresponding to the discharging is obtained. The ratio between the difference and the discharging voltage is made to be the deterioration ratio. The deterioration of the storage battery 2 can be judged based on the deterioration ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device having a function of determining the deterioration status of a storage battery used in floating charging or trickle charging.

[0002]

2. Description of the Related Art In recent years, information centered on computers,
The development of the communication field is remarkable. Stationary batteries are widely used as an emergency power source for devices used in these fields in the event of a power failure, etc., and play a role of system compensation.

This stationary battery must supply electric power from the battery to the load device without interruption during a power failure or a load change, and in order to maintain that state at all times, the state of deterioration of the battery must be maintained. Need to figure out.

By the way, when charging a stationary battery, a floating charging method in which a battery and a load are connected in parallel to a charging device and a constant voltage is always applied to the battery to bring it into a charged state, and a circuit separate from the load is used. Therefore, a trickle charging method is generally used in which a minute current is constantly applied to the battery to compensate for capacity loss due to self-discharge of the battery.

The power supply device used in the above charging method is for continuously applying a constant voltage to the battery, and has a function of forcibly reducing the floating charging voltage or the trickle charging voltage supplied from the power supply. Is not found.
On the other hand, as a power supply device using a negative electrode absorption type seal type stationary lead-acid battery, which has a function of increasing the charging voltage called equal charge, the floating charging voltage per cell is usually 2.18V. However, there is a power supply device having a function of increasing the charging voltage to 2.30V after a lapse of a certain period. This uniform charging is intended to eliminate the variation in the self-discharge accumulated value during floating charging, and it is not possible to judge the deterioration state of the battery.

[0006]

Conventionally, in the determination of the deterioration status of a battery, a battery status evaluation cell of several cells or less is selected from the assembled battery that is floatingly charged, and these cells are charged and discharged. Was going by. This method is effective when there is no significant difference in the deterioration status of the individual batteries that form the assembled battery. However, it is not possible to judge the condition of the whole assembled battery or grasp the deterioration condition of each battery.

In order to judge the deterioration status of each battery, it is necessary to carry out a battery discharge test after switching the connection between the power supply and the load from the main battery to the spare battery. However, the method of replacing the spare battery has a problem that the reliability of the system is deteriorated due to the switching of the battery. Further, in order to maintain the reliability of the entire system during the discharge test, it is necessary to select a spare battery having a capacity close to that of the main battery, which requires a large amount of test cost.

[0008]

In order to solve the above-mentioned problems, a power supply device of the present invention uses a floating charging voltage or a trickle charging voltage value supplied from a charging device in the device as a load from an electromotive voltage of a storage battery itself. The storage battery is discharged without affecting the load connected to the storage battery by providing the control means for forcibly reducing the value to the minimum allowable operating voltage of the device. Further, it has means for estimating the discharge duration of the storage battery from the theoretical discharge capacity and the actual discharge capacity at the discharge current value and determining the deterioration status.

[0009]

According to the present invention, by adopting the above configuration, it is possible to judge the deterioration state of the battery and to estimate the discharge duration without affecting the load.

[0010]

The present invention will be described in detail below with reference to examples.

FIG. 1 shows the basic circuit configuration of the power supply device of the present invention. A storage battery 2 and a load 3 are connected in parallel to the charging device 1. This charging device 1 uses a commercial power source as an input power source and converts it into a floating charging voltage most suitable for the storage battery 2,
And the load 3 is supplied with electric energy. Load 3
Usually, a telephone exchange, an emergency lighting, or the like is used for.
In this example, a telephone exchange was used as the load. The minimum allowable operating voltage of this telephone exchange is 43V and the load current is 20A.

As the storage battery 2, a negative electrode absorption type sealed lead storage battery having a 10-hour rate capacity of 200 Ah was used, and 24 of these were connected in series. The floating charging voltage supplied from the charging device 1 is 54 so that the charging voltage is 2.25V per cell.
Set to V.

In order to judge the state of deterioration of the storage battery, the output voltage of the charging device is forced by the control means to 45.6.
The discharge test was conducted by lowering to V and using a telephone exchange as a load.

FIG. 2 shows changes in the output voltage 4 of the charging device, the discharging voltage 5 of the storage battery, the output current 6 of the charging device and the discharging current 7 from the storage battery during the test. The output voltage 4 of the charging device 1 is maintained at 54V before the start of the test. At the point A when the test starts, the output voltage 4 of the charging device is forced to 4
It is lowered to 5.6V. At this time, the output voltage 4 of the charging device becomes lower than the discharging voltage 5 of the storage battery, the discharging from the storage battery 2 starts, and no current is supplied from the charging device to the storage battery. The storage battery 2 continues discharging until the point B where the discharge voltage reaches 45.6V.

When the discharge voltage of the storage battery 2 drops to 45.6V, the charging device 1 maintains the output voltage of 45.6V, the power supply is switched, and the storage battery 2 does not discharge. Even at this time, the telephone exchange, which is the load 3, is not affected because the voltage exceeding the minimum allowable operating voltage 43V is applied.

Further, even if a power failure occurs during the test, since the storage battery 2 has a remaining capacity exceeding the minimum allowable operating voltage of the telephone exchange, the discharge can be restarted and the function of the telephone exchange can be maintained. it can.

The output voltage 4 of the charging device, which is lowered during the discharge test, takes into consideration the remaining capacity of the storage battery 1,
Any value between the electromotive voltage of the storage battery and the allowable minimum operating voltage of the load can be set.

As described above, by measuring the discharge current and the terminal voltage of all the batteries during or after the discharge test, the deterioration state of each battery can be grasped.

When discharging using a telephone exchange as a load as in this embodiment, the difference between the discharge voltage at the time of test termination and the standard voltage at the theoretical discharge capacity corresponding to the discharge is obtained. The ratio of this difference and the discharge voltage is taken as the deterioration rate, and the capacity can be calculated by multiplying the discharge capacity obtained from the standard discharge characteristics by the deterioration rate.

For the standard discharge characteristic, the conversion coefficient calculated from the relationship between the discharge characteristic and the voltage for each temperature is stored in the microcomputer in the form of a matrix or a conversion formula, and the standard voltage value after the lapse of the specified time is stored. The deterioration rate can be obtained by comparing with the measured voltage. Further, the deterioration rate can be multiplied by the discharge time to calculate the dischargeable time including the deterioration rate.

It is also possible to decrease the output of the charging device in a short time and judge the deterioration of the storage battery from the degree of decrease in the discharge voltage at that time.

[0022]

As described above, the power supply device of the present invention is capable of arbitrarily setting the depth of discharge of the storage battery and enabling the determination of the deterioration state of the storage battery without affecting the load. Since there is no work to disconnect the battery and the storage battery, reliability during the discharge test can be kept high.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic circuit configuration of a power supply device of the present invention.

FIG. 2 is a diagram showing changes in output voltage of a charging device and discharge voltage of a storage battery, and output current of a charging device and discharge current of a storage battery.

[Explanation of symbols]

 1 Charging device 2 Storage battery 3 Load 4 Output voltage of charging device 5 Discharge voltage of storage battery 6 Output current of charging device 7 Discharge current of storage battery

Claims (3)

[Claims] 1. A storage battery charged by a floating charging method or a trickle charging method, and the output voltage of the storage battery is forced to an arbitrary value between the electromotive voltage of the storage battery itself and the minimum allowable operating voltage of a device serving as a load. A power supply device, which is provided with a control unit that lowers the electric power. 2. The discharge voltage, discharge current and discharge time of the storage battery and the storage battery temperature are measured, the theoretical discharge capacity at the discharge current value and the discharge capacity estimated from the measured value are compared, and the storage battery is calculated from the capacity ratio of these. A power supply device having means for estimating a deterioration rate of the power supply device. 3. The power supply device according to claim 2, wherein the deterioration rate of the storage battery is estimated without electrically disconnecting the storage battery and the load.