JPH0754349B2 - Battery capacity tester - Google Patents

Description

TECHNICAL FIELD The present invention relates to a storage battery capacity test apparatus, and more particularly to a capacity test apparatus capable of automatically and accurately measuring the capacity of a storage battery in a floating charge state.

(Prior Art and Problems Thereof) As shown in FIG. 2, for example, an output of an AC power source (1) is rectified by a rectifying device (2) to supply power to a load (3), and a rectifying device ( Used by a power supply device which is connected in parallel to 2) in a so-called floating charging state by connecting the assembled storage battery (4) so that power can be supplied to the load from the assembled storage battery (4) when the AC power supply (1) fails. To be

By the way, in order to fully supply electric power to the electric charge (3) at the time of power failure of the AC power source (1), it is important to always maintain the storage batteries constituting the assembled storage battery (4) normally. It is necessary to occasionally check the remaining life of the assembled battery, that is, the capacity that can be stored. Therefore, in the conventional method, the following method, that is, the total amount of electricity provided in the assembled battery is completely discharged, the discharge is stopped when the terminal voltage drops to a predetermined value, and the discharge amount is calculated from the time integrated value of the discharge current during that period. The capacity of the assembled battery is checked by using the fact that the capacity can be known by determining

However, in the practice of this method, conventionally, the assembled storage battery (4) is completely discharged, so that the power supply to the load (3) is stopped at the time of a power failure of the AC power supply (1) under test, and the load system is brought down. There are drawbacks.

Therefore, it is absolutely necessary to take countermeasures for loads that cannot tolerate blackouts.

Therefore, in recent years, in order to solve the above problems, a method has been proposed in which the storage battery to be tested can be tested in the floating charge state without being removed from the power supply device. This method is the third
As shown in the figure, one to a plurality of storage batteries (4a) among the storage batteries (4) (hereinafter, referred to as a storage battery to be measured), assuming that the storage batteries constituting the storage battery (4) have substantially the same characteristics.
For example, a discharge circuit (5) having a transistor as a main circuit element is connected to the control circuit (6), and the control circuit (6) controls the discharge circuit (5) to discharge at a constant current. When the voltage detector (7) detects that the voltage of the storage battery (4a) to be measured has dropped to a predetermined value, the control unit (6) stops the discharge by the discharge circuit (5) and the current integrator (8). ), The control unit (6) controls the charging circuit (9) to return the battery to be measured (4a) to a predetermined charged state.

According to this method, the problem of the load system going down due to the power failure of the AC power source (1) can be solved. However, on the other hand, this method causes a new problem that not only the accuracy of measuring the discharge amount is deteriorated but also the accuracy of charging is deteriorated.

(Object of the Invention) The present invention has been made for the purpose of providing a test apparatus capable of accurately measuring the capacity of a storage battery in a floating charge state and also highly accurately charging the battery after measurement. It is a thing.

[Means of the Present Invention for Solving Problems] According to the present invention, it has been clarified from FIG. 3 that the decrease in measurement accuracy of the device capable of performing the capacity test in the floating charge state is due to the following reason. It was made based on the results. That is, in the method of discharging by the discharge circuit (5) in the floating charge state as in the method shown in FIG. 3, it is a necessary condition that the storage battery (4a) under discharge is not charged or discharged by any means other than the discharge circuit (5). Is. However, in the case of a load that causes a transient fluctuation such that the power supply including the rectifier (2) responds to the fluctuation and cannot supply electric power during discharging, the above condition cannot be maintained.

For example, if there is a transient increase in load that the rectifier (2) cannot respond to in the case of FIG. 3, the load (3)
There is no choice but to supply the increased amount of electric power required by the assembled storage battery (4). Therefore, the actual discharge amount of the storage battery (4a) to be measured is the constant current discharge current of the discharge circuit (5) plus the discharge current due to the increase of the load, which is measured by the current integrator (8). The discharge amount becomes smaller than the actual discharge amount and does not give the true discharge amount. As a result, the measurement accuracy is lowered. Such a reduction in accuracy is also caused when the load transiently decreases during the discharge test and a charging current flows in the assembled battery (4). Occurs.

In addition to this, the charge and discharge of the assembled storage battery (4) based on the change of the load affects not only the discharge test as described above but also the charging accuracy of the measured storage battery (4a) performed after the discharge test. Appears as a drop. For example, if the rectifier (2) causes a transient load reduction (3) that is difficult to respond to,
Although the charging current flows as described above, if this occurs during charging, the charging current of the measured storage battery (4a) is the sum of the charging current of the charging circuit (9) and the charging current of the assembled storage battery (4) due to load fluctuation. Become. Therefore, for example, the current integration circuit (8)
Even if the current and charging time by the charging circuit (9) are set to charge the storage battery (4a) to be measured by the same amount as the discharging amount by 1.2 times or 1.2 times the discharging amount, the actual charging amount is the charging current based on the load fluctuation. As the amount of charge increases, the accuracy of charging decreases, and the accuracy also decreases when the assembled battery (4) is discharged during charging.

The present invention is conceived from the above. That is, as in the conventional device shown in FIG. 3, not only the discharge current of the measured storage battery (4a) but also the charging current by the charging circuit (9) and the discharge current or charging current flowing in the assembled storage battery (4) are detected. . Then, the discharge current or the charging current of the storage battery to be measured, which is caused to flow by the discharge circuit (5) and the charging circuit (9) by the discharge current or the charging current of the assembled storage battery (4), is corrected and controlled to be a constant current, and the discharge is performed by the current integrator. This is done with the idea that by measuring the amount of charge or the amount of charge, it is possible to eliminate a decrease in the measurement accuracy of the discharge amount or a decrease in the charge accuracy based on the discharge current or the charge current of the assembled storage battery (4). Next, the present invention will be described in detail with reference to examples.

(Structure of Embodiment) FIG. 1 is a circuit diagram of an embodiment of the present invention. In the figure, (1) is an AC power supply, (2) is a rectifier, (3) is a load,
(4) is an assembled battery, (4a) is a measured battery, (5) is a discharge circuit, (6) is a control unit, (6a) is a test start command unit,
(6b) is a setting unit for the discharge current, charging current, charging time, etc.
(7) is a voltage detector, (9) is a charging circuit, and (10) is a diode for preventing deterioration due to reverse charging of the storage battery (4a) to be measured at the time of AC power failure. The circuit configuration is the same as that shown in FIG.
The features of the present invention are as follows.

That is, in the present invention, the charging circuit (9) and the discharging circuit (5)
Between one end of the parallel connection end of and the one end of the storage battery (4a) to be measured,
The current detector (11) is connected so that the discharge current and charging current of the storage battery (4a) to be measured can be detected by one current detector, and at the same time, the current detector is also provided in the circuit of the assembled storage battery (4). (12) is provided. Then, the detection currents of both current detectors (11) and (12) are added to the sum detector (13) to determine the discharge current of the storage battery (4a) to be measured (5) and the discharge current of the assembled storage battery (4). Take the sum. The discharge circuit (5) of the storage battery (4a) to be measured is controlled by the control unit (6) so that the sum of the discharge currents becomes a constant discharge current preset by the setting unit (6b). It is characterized in that the current integrator (8) integrates the current to measure the discharge amount.

(Operation of Example) When the storage battery (4a) to be measured is being discharged by the discharge circuit (5) controlled by the control unit (6), the assembled storage battery (4) is caused by the transient fluctuation of the load (3). It is assumed that the discharge current flows from the. Therefore, both discharge currents now flow out from the same battery circuit, so the detectors (11) and (12) detect the discharge current i _d from the measured battery (4a) and the discharge current I _D from the assembled battery (4). The currents have the same polarity. Therefore, the sum detector (13) detects the sum i _d + _ID of the discharge current of the storage battery to be measured and the discharge current of the assembled battery (4), and the discharge current of this sum i _d + _ID is set by the setting unit ( The discharge circuit (5) is controlled by the control unit (6) so as to reduce the discharge current i _d of the storage battery (4a) to be measured so that the constant discharge current set by 6b) is obtained, and the current integrator (8) ) Will integrate this. Therefore, the current integrator (8) also integrates the discharge current of the assembled battery (4) which is not corrected in the conventional circuit shown in FIG. 3, so that the integration result of the current integrator (8) is the measured battery ( It will give the true discharge amount of 4a).

Also, due to the transient fluctuation of the load, the charging current to the assembled battery (4) is increased.
When I _C flows, its polarity is opposite to the discharge current i _d by the discharge circuit (5). Therefore, the control unit (6) controls the difference i _d −I _C between the discharge current of the measured storage battery (4a) and the charging current of the assembled storage battery (4) to be a predetermined constant discharge current. , The discharge circuit (5) is controlled so as to increase the discharge current i _d of the storage battery (4a) to be measured. Therefore, the integration result shows the true discharge amount of the storage battery (4a) to be measured, and the discharge amount can be measured with high accuracy.

On the other hand, after completion of the discharge test, the charging circuit (9) operates according to a command from the control unit (6) to charge the storage battery under test (4a) with a charging current i _c.
When the charging current i _c flows to the assembled storage battery (4) due to load fluctuation, the charging current of the sum i _c + I _C flows to the measured storage battery (4a), and the assembled storage battery (4) when the discharge current I _D flows from), either the measured battery (4a) the charging current flows of the difference i _c -I _D, the sum i _c + I _C or difference
charging current i _c -I _D is such that a constant charging current set in advance by the setting unit (6b), the control unit to increase or decrease the charging current i _c of the measured battery (4a) (6) Control the charging circuit (9). When the charging by the charging circuit (9) is completed, the integration result shows the true charge amount of the storage battery to be measured.

Therefore, for example, a subtracter capable of setting the discharge amount by the current integrator (8) is used to subtract the charge amount by the current integrator (8) from the set value, and when the output becomes zero, the control unit (6)
Therefore, if the charging by the charging circuit (9) is stopped or the charging amount is set to 1.2 times and the charging circuit (9) is similarly controlled, high-quality charging is performed and the charging accuracy can be greatly improved.

(Other Embodiments) Although one embodiment of the present invention has been described above, if charging by the charging circuit (9) is performed with a constant current, not only the charging time can be set by a timer but also charging can be performed. Since the current can be changed freely, it can be applied to the testing of a wide range of storage batteries. Also, in the case of constant voltage charging, if the voltage setting value is increased, a large current flows when the voltage of the storage battery is low, which adversely affects a small capacity storage battery, and at the same time drooping operation occurs until the storage battery voltage reaches the voltage setting value. Stable charging cannot be performed. However, constant current charging does not cause the disadvantages of constant voltage charging. Note that constant current charging may be performed first and then constant voltage charging may be performed when the terminal voltage of the storage battery rises.

(Effects of the Invention) As is apparent from the above, according to the present invention, the capacity of the storage battery can be automatically measured accurately in the floating charging state, and the storage battery after the test can be charged with high charging accuracy.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a circuit diagram of a power supply device, and FIG. 3 is a circuit diagram of a conventional capacity test device. (1) …… AC power supply, (2) …… Rectifier, (3) ……
Load, (4) ... assembled battery, (5) ... discharge circuit, (6)
...... Control unit, (7) ...... Voltage detector, (8) ...... Current integrator, (8a) ...... Discharge current detector, (9) ...... Charging circuit, (10) ...... Reverse charge prevention diode , (11) ... discharge of measured battery, charging current detector, (12) ... discharge of assembled battery, charging current detector, (13) ... sum detector.

Claims (1)

[Claims] 1. A measured storage battery selected from an assembled storage battery in a floating charge state is discharged by a discharge circuit controlled by a control unit, and is discharged by the discharge circuit when the voltage of the measured storage battery drops to a predetermined value. In the capacity testing device of the storage battery, the storage battery capacity is determined from the measured discharge amount by integrating the discharge current within the discharge time by the discharge circuit with the current integrator and charging the battery by the charging circuit. A first current detector provided in a common circuit of the discharging circuit and the charging circuit so as to detect a discharging current or a charging current flowing in the discharging circuit and the charging circuit,
A second current detector provided to detect a discharge current or a charging current flowing in the assembled battery; and the measured storage battery and the assembled battery detected by the first current detector and the second current detector. A sum detector provided to take the sum of the discharge current and / or the charge current, and the output current of the sum detector detected during the discharge operation or the charge operation of the capacity test of the storage battery to be measured is Measure the capacity of the storage battery to be measured by controlling the discharge circuit or the charging circuit that increases or decreases the discharge current or charging current of the storage battery to be measured by the control unit so as to have a set constant discharge current or charging current. A storage battery capacity testing device characterized by improving accuracy and charging accuracy.