JP2004257742A - Apparatus and method for determining degradation of storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine the presence or absence of degradation of a storage battery during the operation of a load in an apparatus and a method for determining degradation of the backup storage battery for an electric power supply. <P>SOLUTION: The storage battery degradation determining apparatus includes: a current detection circuit by a resistor 4 etc. for detecting a current supplied for the load 3; an electronic load circuit including a transistor 10 etc. capable of regulating a passing current by applying a voltage of the storage battery at the determination of degradation of the storage battery 1; a current control circuit 11 for controlling the electronic load circuit in such a way that the sum of the current supplied for the load 3 and the current passing though the electronic load circuit may become a prescribed value corresponding to the capacity of the storage battery 1 at the determination of degradation of the storage battery 1; and a determining circuit 15 for determining the presence or absence of degradation of the storage battery 1 by measuring changes in a terminal voltage of the storage battery 1 at the determination of degradation of the storage battery 1. It is determined that the storage battery 1 has degraded when the terminal voltage is reduced to a determination voltage or lower. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a storage battery deterioration determination device and a storage battery deterioration determination method for determining whether a backup storage battery for a power supply such as a switching power supply that supplies operating power to a load has deteriorated.
[0002]
[Prior art]
Power supplies such as switching power supplies for supplying operating power to loads such as various electronic circuits are required to have an uninterruptible configuration. For this purpose, a configuration is known in which a storage battery is provided as a backup and is constantly charged from a power supply, and when a power failure or power failure occurs, operating power is supplied to the load from the backup storage battery.
[0003]
Such a backup storage battery supplies operating power to the load only at the time of a power failure or a failure, so it is necessary to monitor whether the storage battery operates normally. However, even if the terminal voltage of the storage battery is normal, if the operating power is supplied to the load, the terminal voltage may decrease in a short time, and the operating power may not be continuously supplied for a predetermined time. That is, the storage battery may deteriorate to a state where the predetermined capacity cannot be maintained.
[0004]
Various means have already been proposed as means for judging the deterioration of the storage battery, such as performing a large current discharge for a certain period of time, measuring the terminal voltage after the discharge, and judging deterioration when the voltage drops below a predetermined value. Is common. Further, for example, there is known a means in which a storage battery is pulse-discharged at a constant current value, an internal impedance is obtained based on a change in terminal voltage, and deterioration of the storage battery is determined based on an increase in the internal impedance (for example, Patent Document 1). 1).
[0005]
[Patent Document 1]
JP 2000-121710 A
[Problems to be solved by the invention]
In general, the conventional storage battery deterioration determination means is performed separately from the load. However, since the backup storage battery is used as a backup for a power supply such as a switching power supply, it is necessary to always wait in a state where current can be supplied to the load. Therefore, unlike the conventional deterioration judging means, the test cannot be performed by separating the storage battery from the load.
An object of the present invention is to make it possible to determine the deterioration of a storage battery in a state where backup is always possible.
[0007]
[Means for Solving the Problems]
The storage battery deterioration determination device of the present invention will be described with reference to FIG. 1. The storage battery deterioration determination device determines whether the backup storage battery 1 has deteriorated with respect to a power supply 2 such as a switching power supply that supplies operating power to loads 3 such as various electronic circuits. A battery deterioration determination device for detecting a current supplied from a power supply 2 or a storage battery 1 to a load 3, a current detection circuit including a resistor 4, a comparator 5, and the like. The sum of the current supplied to the load 3 from the storage battery 1 and the current flowing through the electronic load circuit is determined only when the deterioration of the storage battery 1 is determined, and the storage load is the storage battery. The current control circuit 11 controls the electronic load circuit so as to have a predetermined value corresponding to the capacity of the storage battery 1. And it has a configuration including a determining circuit 15 whether a degradation of.
[0008]
Further, when the deterioration of the storage battery 1 is determined, the current flowing through the load 3 and the current flowing through the electronic load circuit may be detected by the same current detection circuit. Further, a timer 12 can be provided for starting the storage battery 1 when the deterioration determination is started, resetting the storage battery 1 when the deterioration determination period elapses, and disconnecting the storage battery 1 from the electronic load circuit. Further, the determination circuit 11 can have a configuration in which the storage battery and the electronic load circuit are disconnected when the voltage of the storage battery 1 changes greatly during the deterioration determination period of the storage battery 1 and the deterioration of the storage battery 1 is determined. .
[0009]
The storage battery deterioration determination method according to the present invention is a storage battery deterioration determination method for determining whether or not the backup storage battery 1 has deteriorated with respect to the power supply 2 that supplies operating power to the load 3, wherein the output voltage of the power supply 2 is reduced or cut off. A current is supplied to the load 3 only from the storage battery 1, and a current flowing through an electronic load circuit connected to the storage battery 1 is controlled so that the current has a predetermined value corresponding to the capacity of the storage battery 1. When the change in the terminal voltage of the storage battery within the battery is greater than or equal to a predetermined value, it is determined that the battery has deteriorated.
[0010]
Further, a step of disconnecting the storage battery and the electronic load circuit when it is determined that the storage battery has deteriorated during the deterioration determination period of the storage battery 1 can be included. It also detects whether or not a charging current flows from the power supply 2 to the storage battery 1, monitors the connection state between the power supply 2 and the storage battery 1, and determines the deterioration of the storage battery when the storage battery 1 is not connected to the power supply 2. The method may include a step of stopping.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is an explanatory view of an embodiment of the present invention, wherein 1 is a backup storage battery, 2 is a power supply having a configuration of rectifying an AC voltage and outputting a DC voltage, a switching power supply or the like, and 3 is an electronic device. Load of a circuit, etc., 4 is a resistor for detecting a load current, 5 is a comparator for detecting a load current, 6 is an addition circuit, 7 is a switch circuit that is turned on when a storage battery deterioration judgment is started, and 8 is a current flowing through an electronic load circuit. , A comparator 9 for detecting current, a transistor 10 for forming an electronic load circuit, a current control circuit 11 for controlling a current flowing through the electronic load circuit, a timer 12, and temperature detection 13 and 14. , 15 is a judgment circuit, 16 and 17 are resistors, and 18 is a reference power supply for current control.
[0012]
The output voltage of the power supply 2 is set higher than the terminal voltage of the storage battery 1 to charge the storage battery 1, and always supplies the operating power to the load 3 while charging the storage battery 1. When the output voltage of the power supply 2 decreases or becomes zero due to a power failure or a failure, the terminal voltage of the storage battery 1 increases, and operation power is supplied from the storage battery 1 to the load 3. That is, a backup function for the power supply 2 can be performed. In this case, a diode or the like (not shown) is provided so as not to flow backward to the power supply 2.
[0013]
In order to determine the deterioration of the storage battery 1, a current detection circuit for detecting the voltage across the resistor 4 as a current value, a transistor 10 for applying the voltage of the storage battery 1 via the switch circuit 7, and controlling the flowing current, and the like. An electronic load circuit, a current detection circuit including a comparator 9 for detecting a current flowing through the electronic load circuit as a voltage across the resistor 8, and a current supplied from the storage battery 1 to the load 3 only when the deterioration of the storage battery 1 is determined. A current control circuit 11 for controlling the electronic load circuit so that the sum of the current flowing through the electronic load circuit and the sum of the output signal levels of the comparators 5 and 9 becomes a predetermined value corresponding to the capacity of the storage battery 1. And a determination circuit 15 for measuring a change in the terminal voltage of the storage battery 1 at the time of determining the deterioration of the storage battery 1 and determining whether or not the storage battery 1 has deteriorated. It also includes a timer 12, temperature detectors 13, 14, and the like.
[0014]
When the deterioration of the storage battery 1 is determined, a deterioration determination start signal and a current adjustment signal corresponding to the current capacity of the storage battery 1 are input. In response to the deterioration determination start signal, the power supply 2 controls the output voltage to be lower than the terminal voltage of the storage battery 1 or to be zero, thereby, as in the backup operation, only the load 3 from the storage battery 1. Is supplied with operating power. In response to the deterioration determination start signal, the switch circuit 7 is turned on, an electronic load circuit including a series circuit of the resistor 8 and the transistor 10 is connected to the storage battery 1 in parallel, and operating power is supplied from the storage battery 1 to the load 3. A predetermined current is passed through the electronic load circuit, and the storage battery 1 is set to a state in which a current of a predetermined ratio corresponding to the current capacity flows.
[0015]
Further, the timer 12 is started by the deterioration determination start signal. The timer 12 outputs a signal for turning off the switch circuit 7 when the deterioration judgment period has elapsed, and the timer 12 outputs a signal for validating the current adjustment signal to the current control circuit 11 during the deterioration judgment period from startup. Input to the control circuit 11. For example, the output terminal of the timer 12 that outputs this signal is always low impedance so that the reference power supply 18 and the current amount adjustment signal are bypassed so as not to be input to the current control circuit 11, and during the period from the start to the deterioration determination period. Can be configured so that the current control circuit 11 performs a control operation using the reference power supply 18 and the current amount adjustment signal as high impedance.
[0016]
In response to the deterioration determination start signal, the determination circuit 15 starts measuring the terminal voltage of the storage battery 1, measures a change in the terminal voltage of the storage battery 1 during a predetermined deterioration determination period, compares the measured change with the deterioration determination voltage, When the terminal voltage of the storage battery 1 becomes equal to or lower than the deterioration determination voltage, it is determined that the storage battery 1 has deteriorated, and, for example, a red light emission display is performed or an alarm sounds. At the time of this deterioration determination, the switch circuit 7 is turned off through a path not shown, and the deterioration determination operation is completed. If the voltage does not drop below the deterioration determination voltage, it is determined that there is no deterioration, and for example, blue light emission display can be performed. Further, the deterioration determination start signal can be automatically input at regular intervals from a higher-level control device or the like (not shown) or manually input when necessary.
[0017]
When the switch circuit 7 is turned on, the electronic load circuit including the resistor 8 and the transistor 10 is connected to the storage battery 1, and the resistor 8 and the comparator 9 detect the electronic load current flowing through the transistor 10. I do. The load current flowing through the load 3 is detected by the resistor 4 and the comparator 5, and the sum of the load current and the electronic load current is obtained by the adding circuit 6 and input to the current control circuit 11. The current control circuit 11 controls the transistor 10 by comparing the current value from the adder circuit 6 with a value obtained by adjusting the voltage of the reference power supply 18 by the current amount adjustment signal.
[0018]
In the determination of the deterioration of the storage battery, for example, a change in terminal voltage of the storage battery is generally measured by setting the current capacity of the storage battery to 30% so that the determination current is referred to as 0.3 C. If the current capacity is, for example, 200 A, the deterioration determination is performed with the determination current set to 60 A. As described above, the judgment current at the time of judging the deterioration of the storage battery 1 is set by the current amount adjustment signal, and the difference between the judgment current and the load current flowing through the load 3 is provided to the transistor 10 constituting the electronic load circuit. Is controlled to flow.
[0019]
2A and 2B are explanatory diagrams of the deterioration judging operation. FIG. 2A shows a good state, FIG. 2B shows a deteriorated state, and FIGS. 2A and 2B show an output voltage Va of the power supply 2 and (a). (b) shows the current Ib of the storage battery 1, (c) shows the terminal voltages Vb0 and Vb1 of the storage battery 1, Vr shows the deterioration determination voltage, T1 shows the deterioration determination period, and T2 shows an example period when deterioration occurs.
[0020]
Upon the start of the deterioration determination, the output voltage Va of the power supply 2 is reduced to zero or zero from the terminal voltage Vb0 of the storage battery 1, and the current Ib is supplied to the load 3 and the electronic load circuit. Thereby, the terminal voltage Vb0 of the storage battery 1 gradually decreases like Vb1. If the voltage does not drop below the deterioration determination voltage Vr after the deterioration determination period T1 has elapsed, it is determined to be good.
[0021]
When the storage battery 1 is in good condition and deteriorates, the terminal voltage Vb1 of the storage battery 1 becomes equal to or lower than the deterioration judgment voltage Vr within the deterioration judgment period T1 as shown in (c) of FIG. At that time, under the control of the determination circuit 15, the switch circuit 7 is turned off, and the output voltage of the power supply 2 is returned to normal Va. That is, when the deterioration is determined in the period T2 within the deterioration determination period T1, the deterioration determining operation is stopped, and the extra discharge to the storage battery 1 is stopped.
[0022]
The temperature detectors 13 and 14 detect the temperature of the current measuring resistor 8, the transistor 10, and other circuit parts. If the temperature exceeds a predetermined temperature, a failure such as burning occurs. Thereby, the switch circuit 7 is turned off, and the operation of determining the deterioration of the storage battery 1 is stopped. Further, the switch circuit 7 is turned off after the elapse of the deterioration judgment period T1 by the judgment circuit 15, and the deterioration judgment operation is stopped. However, when this operation cannot be performed, the timer 12 started by the deterioration judgment start signal is used. The switch circuit 7 is turned off when the deterioration determination period has elapsed, and the deterioration determination operation can be stopped.
[0023]
FIG. 3 is an explanatory view of another embodiment of the present invention, wherein the same reference numerals as in FIG. 1 indicate the same functional portions, 21 indicates a current measuring resistor, and 22 indicates a comparator. In this embodiment, since the sum of the load current flowing through the load 3 and the electronic load current flowing through the electronic load circuit including the transistor 10 flows through the resistor 21, the resistor 4 and the comparator 5 shown in FIG. And the addition circuit 6 can be omitted. The operation of determining the deterioration of the storage battery 1 is the same as that shown in FIG.
[0024]
Although the case where the resistors 4, 8, and 21 are used for current detection is shown, a current transformer configured to measure a direct current may be used. It is also possible to adopt a configuration in which the function of the switch circuit 7 is realized by the transistor 10 forming the electronic load circuit. That is, the current control circuit 11 starts operating in response to the deterioration determination start signal, turns on the transistor 10, and controls so that a current flows according to the current amount adjustment signal. In that case, a trip circuit that shuts off the switch circuit 7 by an abnormal temperature rise detection signal from the temperature detectors 13 and 14 can be used. Although the electronic load circuit is shown using a field effect transistor, a transistor such as a bipolar transistor may be used.
[0025]
【The invention's effect】
As described above, the present invention relates to a storage battery deterioration determination device and a storage battery deterioration determination method for determining whether the backup storage battery 1 of the power supply 2 has deteriorated. The current control circuit 11 controls the shortage of the load current to be supplied to the electronic load circuit including the transistor 10, and the change in the terminal voltage of the storage battery 1 is measured by the judgment circuit 15 and compared with the judgment voltage. This is for determining whether or not the storage battery 1 has deteriorated, and has the advantage of determining whether or not the backup storage battery 1 of the power supply 2 has deteriorated even if the operation of the load 3 is continued and its operation state fluctuates.
[0026]
In addition, since the electronic load circuit can be controlled so that a current corresponding to the current capacity of the storage battery 1 flows, the presence or absence of deterioration of various backup storage batteries can be determined periodically or as needed, and the backup storage battery can be determined. There is an advantage that can contribute to improvement in reliability.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of one embodiment of the present invention.
FIG. 2 is an explanatory diagram of a deterioration determination operation.
FIG. 3 is an explanatory diagram of another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Storage battery 2 Power supply 3 Load 4 Resistance 5 Comparator 6 Addition circuit 7 Switching circuit 8 Resistance 9 Comparator 10 Transistor 11 Current control circuit 12 Timer 13, 14 Temperature detector 15 Judgment circuit 18 Reference power supply for current control

Claims (7)

In a storage battery deterioration determination device that determines whether or not a backup storage battery has deteriorated with respect to a power supply that supplies operating power to a load,
A current detection circuit for detecting a current supplied from the power supply or the storage battery to the load,
An electronic load circuit that can adjust a current flowing by applying a voltage of the storage battery when determining the deterioration of the storage battery;
Current control for controlling the electronic load circuit so that the sum of the current supplied from the storage battery to the load and the current flowing to the electronic load circuit becomes a predetermined value corresponding to the capacity of the storage battery only when the deterioration of the storage battery is determined. Circuit and
A determination circuit for measuring a change in terminal voltage of the storage battery at the time of determining the deterioration of the storage battery and determining whether or not the storage battery has deteriorated. 2. The storage battery deterioration determination device according to claim 1, further comprising a configuration in which a current flowing through the load and a current flowing through the electronic load circuit are detected by the same current detection circuit when the deterioration of the storage battery is determined. The storage battery deterioration according to claim 1 or 2, further comprising a timer for starting the storage battery when the deterioration determination is started, resetting the storage battery after the deterioration determination period elapses, and disconnecting the storage battery from the electronic load circuit. Judgment device. The determination circuit is configured to disconnect the storage battery and the electronic load circuit when the storage battery has a large voltage change during the storage battery deterioration determination period and the storage battery is determined to be deteriorated. The storage battery deterioration judging device according to claim 1, 2 or 3. In a storage battery deterioration determination method of determining whether a backup storage battery has deteriorated with respect to a power supply that supplies operating power to a load,
The output voltage of the power supply is reduced or cut off, and current is supplied to the load only from the storage battery, and the current flows to an electronic load circuit connected to the storage battery such that the current has a predetermined value corresponding to the capacity of the storage battery. A method for determining deterioration of a storage battery, comprising controlling current and determining deterioration when a change in terminal voltage of the storage battery within a deterioration determination period is equal to or greater than a predetermined value. 6. The method according to claim 5, further comprising the step of disconnecting the storage battery from the electronic load circuit when the storage battery is determined to have deteriorated during the storage battery deterioration determination period. Detecting whether or not a charging current for the storage battery flows from the power supply, monitoring a connection state between the power supply and the storage battery, and stopping determination of deterioration of the storage battery when the storage battery is not connected to the power supply. 6. The method according to claim 5, further comprising the step of:

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