JPH06233475A - Power supply - Google Patents

Abstract

PURPOSE:To provide a system capable of inspecting an energy storing means especially in the cource of its operation, concerning a power device such as an interruptible power source, etc., having an energy storing means such as a battery, etc., and a power converting means such as an inverter, etc. CONSTITUTION:The current of a battery is controlled so that the battery 4 may be discharged by an AC-DC converter 2 during the operation of a DC-AC converter 3. On this occasion, the battery voltage measured by a voltage sensor 13 is to be a value corresponding to the battery current measured by a current sensor 12, when the battery 4 is normal. But, if the battery 4 is out of order or is not charged sufficiently, the voltage of the battery becomes lower in value than the normal range. A battery malfunction detector 14 detects malfunction, and outputs a malfunction signal.

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 an energy storage means such as a storage battery and a power conversion means such as an inverter, and more particularly to a system capable of inspecting the energy storage means.

[0002]

2. Description of the Related Art Conventionally, an uninterruptible power supply system capable of supplying electric power to a load by combining energy storage means such as a storage battery and electric power conversion means such as an inverter even when energy supply from another is cut off has been known. well known. Such an uninterruptible power supply is used to configure a power supply system that supplies power to a load such as a computer that requires continuous operation even when a power failure occurs in the power system. It

FIG. 12 shows, for example, "an uninterruptible power supply (UP).
S) Introduction battle guide "(published on February 25, 1989 by Denki Shoin Co., Ltd.) Page 58 is a configuration diagram showing the conventional uninterruptible power supply device shown in FIG. In the figure, 1 is an AC power supply that supplies AC power to an uninterruptible power supply, 2 is an AC-DC converter that converts the power of the AC power supply 1 into DC power, 3
Is a DC-AC converter that reversely converts the converted DC power into stable AC power, 4 is a storage battery connected to a DC circuit between the two converters 2 and 3, and 5 is a DC-AC converter 3. An output switch connected to the output side of, a 6 is a direct feed (bypass) circuit, 7 is an alternating current (AC) switch connected to the direct feed circuit 6, and 8 is connected to a common connection point of the output switch 5 and the AC switch 7. It is an AC load on the uninterruptible power supply.

Next, the operation will be described. When the AC power supply 1 is normal, the AC power of the AC power supply 1 is converted into DC power by the AC-DC converter 2, and the storage battery 4 is charged by floating (float), and at the same time the DC-AC converter 3 becomes stable AC. The voltage is inversely converted and is supplied to the AC load 8 via the output switch 5. When the AC power supply 1 fails, the storage battery 4 discharges the DC power and supplies the DC power to the DC-AC converter 3, thereby continuing the power supply to the AC load 8. When an overcurrent that exceeds the rating of the DC-AC converter 3 flows in the AC load 8 or the DC-AC converter 3 fails, the AC power of the AC power supply 1 is passed through the direct feed circuit 6 and the AC switch 7. Are directly supplied to the AC load 8.

[0005]

Since the conventional uninterruptible power supply is configured as described above, the operation (floating charging) is performed.
Even if an abnormality (failure) occurs in the storage battery 4 inside, it cannot be detected, and the failure becomes apparent only when the uninterruptible power supply device is in the state of input power failure, and the AC load 8 is continuously fed. There was a fatal defect as an uninterruptible power supply that could not be done.

The present invention has been made to solve the above-mentioned problems, and enables energy storage means such as a storage battery to be inspected during the operation of the apparatus, and the abnormality can be detected in advance to improve reliability. It is an object to provide a high power supply device.

[0007]

In the power supply device according to the first aspect of the present invention, the abnormality can be detected by controlling the power conversion means to a predetermined operating state and causing the energy storage means to perform the energy discharge operation. It is what

According to a second aspect of the present invention, the power supply device detects the current and voltage of the storage battery, and controls the AC-DC converter to a predetermined operating state during operation of the DC-AC converter. A storage battery abnormality detecting means is provided for discharging the storage battery and detecting an abnormality of the storage battery based on an output from the detecting means at the time of discharging.

According to a third aspect of the present invention, in the power supply device according to the present invention, the means for detecting the current and voltage of the storage battery and the DC-AC converter are in operation, the direct feed circuit is closed, and the direct feed circuit is used to connect the direct feed circuit. Storage battery abnormality detection for controlling the DC-AC converter to regenerate the power of the storage battery to an AC power source to discharge the storage battery, and detecting an abnormality of the storage battery based on the output from the detection means at the time of discharging. It is equipped with means.

A power supply device according to a fourth aspect of the present invention controls the AC-DC converter in a regeneration mode to an AC power supply while the means for detecting the current and voltage of the storage battery and the DC-AC converter are in operation. Then, the storage battery is discharged, and the storage battery abnormality detection means for detecting abnormality of the storage battery is provided based on the output from the detection means at the time of this discharge.

According to a fifth aspect of the present invention, the storage battery is judged to be abnormal when the detected storage battery voltage exceeds a preset range with respect to the storage battery current.

According to a sixth aspect of the present invention, the power supply device controls the discharge current or the discharge power of the storage battery to a predetermined value, and the storage battery voltage detected after a predetermined time elapses from the start of the discharge is the storage battery current or the storage battery power. On the other hand, when it exceeds the preset range, it is determined that the storage battery is abnormal.

A power supply device according to a seventh aspect of the present invention cancels the abnormality detecting operation when the storage battery is discharged for a preset time or when the detected storage battery voltage drops below a preset value. The storage battery is returned to the charging operation.

[0014]

In the power supply device according to claim 1 of the present invention, when the power conversion means is controlled to a predetermined operating state, for example, when the conversion part from the first power circuit is stopped, the energy storage means operates. The stored energy is discharged to the second power circuit, and the presence or absence of abnormality of the energy storage means can be determined from the discharge characteristic at that time.

In the power supply device according to the second aspect of the present invention, the AC-DC converter is controlled to a predetermined operating state,
For example, when the storage battery is stopped, the storage battery operates to discharge to an AC load via the DC-AC converter, and the presence or absence of abnormality of the storage battery can be determined from the current and voltage characteristics at that time.

In the power supply device according to claim 3 of the present invention, the DC-AC converter is controlled to regenerate the electric power of the storage battery to the AC power supply through the direct transfer circuit, and the current at that time,
Whether or not there is an abnormality in the storage battery can be determined from the voltage characteristics.

In the power supply device according to the fourth aspect of the present invention, the AC-DC converter is controlled in the regenerative mode to discharge the storage battery to the AC power supply, and whether the storage battery is abnormal or not is determined from the current and voltage characteristics at that time. can do.

Further, as a method of detecting an abnormality of the storage battery, in the case of claim 5, it is determined whether or not the detected storage battery voltage exceeds a set range with respect to the current, and in the case of claim 6, from the start of discharging. It is determined by whether or not the storage battery voltage after a lapse of a predetermined time exceeds a set range with respect to current or power.

Further, in the power supply device according to claim 7 of the present invention, the abnormality detection operation is canceled when the discharge has exceeded the set time or when the storage battery voltage has dropped to the set value or less, and the abnormal discharge due to the inspection is performed. To prevent.

[0020]

EXAMPLES Example 1. 1 is a block diagram showing a power supply device according to a first embodiment of the present invention, in which 1 to 4 and 8 are the same as the conventional one. Further, 10 is a control device for the AC-DC converter 2, 11 is a control device for the DC-AC converter 3, 12 is a current sensor that measures the discharge current of the storage battery 4, and 13 is a voltage sensor that measures the voltage of the storage battery 4. , 14 are both sensors 1
A storage battery abnormality detector that detects an abnormality of the storage battery 4 from the measured values of 2 and 13 and sends an abnormality signal, and 15 is an inspection control device that sends a command signal to the control devices 10 and 11 and the storage battery abnormality detector 14 when checking the storage battery. .

Next, the operation will be described. The original operation of the power supply device, that is, the AC power from the AC power supply 1 is once converted into DC power by the AC-DC converter 2, and further DC-
The operation of inversely converting into stable AC power by the AC converter 3 and supplying the AC power to the AC load 8 is the same as the conventional one. At this time, the storage battery 4 is in a floating charge state.

Here, when an inspection command signal is sent from the inspection control device 15 while the power supply device is operating, the control device 10 of the AC-DC converter stops the output of the AC-DC converter 2. As a result, the storage battery 4 changes from the floating charging state up to that time to the discharging state, and the power of the storage battery 4 is supplied to the AC load 8 via the DC-AC power converter 3. At this time, if the storage battery 4 is normal, the storage battery voltage measured by the voltage sensor 13 should be a value according to the storage battery current measured by the current sensor 12, but the storage battery 4 is out of order or is sufficiently charged. If not, the storage battery voltage becomes a value lower than the normal characteristic, and the storage battery abnormality detector 14 detects an abnormality and sends an abnormality signal.

FIG. 2 is a characteristic diagram showing the relationship between the storage battery current and the storage battery voltage as described above. If the storage battery is in the normal range, the voltage decreases with respect to the current depending on the charging state. It has characteristics. The storage battery abnormality detector 14 detects the state of charge of the storage battery from the measured values of the storage battery current and the storage battery voltage, and determines whether or not the relationship between the storage battery current and the storage battery voltage is within the normal range. Anomalies can be detected. In this embodiment, the abnormality of the storage battery 4 can be detected in advance by simulating the input power failure state as described above. Even when the AC load 8 is not connected, the no-load loss of the DC-AC converter 3 is supplied from the storage battery 4, so that the abnormality of the storage battery 4 can be detected. Further, even when the AC load 8 is being supplied, if the storage battery is abnormal, the AC-DC converter 2 can be quickly restarted to avoid affecting the AC load 8.

Example 2. Next, a description will be given of a second embodiment in which the discharge of the storage battery 4 is controlled under a constant condition so that the abnormality can be detected more stably and surely. The overall structure is the same as that shown in FIG.

Next, the operation will be described. During the operation of the DC-AC converter 3, the control device 10 of the AC-DC converter controls the AC-DC converter 2 and the storage battery 4 is discharged at a predetermined current value by the inspection command signal from the inspection control device 15. To control. At this time, if the storage battery 4 is normal, the storage battery voltage measured by the voltage sensor 13 after a predetermined time (time t1) should be a value according to the storage battery current measured by the current sensor 12, but the storage battery 4 If the battery is out of order or is not sufficiently charged for some reason, the storage battery voltage becomes a value lower than the normal characteristic, and the storage battery abnormality detector 14 detects an abnormality and transmits an abnormality signal.

FIG. 3 is a characteristic diagram showing the relationship between the discharge time and the storage battery voltage when such a storage battery is discharged with a constant current. When the capacity of the storage battery decreases, the storage battery after the start of discharge is shown. The voltage drop is significantly increased. The storage battery abnormality detector 14 detects the state of charge of the storage battery from the measured values of the storage battery current and the storage battery voltage after a predetermined time from the start of discharge control, and determines whether or not the capacity of the storage battery is within the normal range. Thus, the storage battery abnormality can be detected.
As described above, by performing the discharge controlled to the predetermined current value, the abnormality presence / absence determination condition in the storage battery abnormality detector 14 is unified, and the operation becomes more stable and reliable. In the above, the current during discharging is controlled to be constant, but the discharging power may be controlled to be constant.

Example 3. Next, a power supply device according to a third embodiment of the present invention will be described. In this embodiment, means for more surely preventing the influence of the inspection operation of the storage battery 4 performed during the operation of the device on the AC load 8 is added,
The structure is shown in FIG. What is different from that of FIG. 1 is a storage battery abnormality detector 14a, which is newly provided with a voltage drop detection function. If the storage battery voltage drops to an abnormal level before the time t1, an abnormal signal is generated and inspection control is performed. A signal to stop inspection is sent to the device 15.

Next, the operation will be described. During the operation of the DC-AC converter 3, the control device 10 of the AC-DC converter controls the AC-DC converter 2 and the storage battery 4 is discharged at a predetermined current value by the inspection command signal from the inspection control device 15. To control. At this time, if the storage battery 4 is normal, the storage battery voltage measured by the voltage sensor 13 after a predetermined time (time t1) should be a value according to the storage battery current measured by the current sensor 12, but the storage battery 4 If the battery is out of order or is not sufficiently charged for some reason, the storage battery voltage drops sharply before reaching time t1, which is not shown in FIG. There is a risk that the DC low voltage protection level of the device set to a low voltage value may be lowered. In such a case, the voltage detector provided in the storage battery abnormality detector 14a detects the abnormal voltage of the storage battery, transmits an abnormality signal, and sends a signal for stopping the inspection to the inspection control device 15 to stop the inspection. Then, since the normal operation is resumed, there is no possibility that an abnormality will occur in the device, and the power supply to the AC load 8 can be stably continued.

It should be noted that the abnormal voltage level when commanding the above-mentioned inspection cancellation is set to a value slightly lower than the storage battery voltage corresponding to the storage battery charge amount = 0% and the storage battery current maximum value shown in FIG. You may do it. Further, after the start of discharging, when a predetermined set time elapses, the inspection may be always stopped and the operation may be restored regardless of the storage battery voltage.

Example 4. Next, a fourth embodiment capable of surely detecting an abnormality regardless of the state of the AC load 8 and the load amount will be described with reference to FIG. In FIG. 5, 11a is a parallel operation control device for operating the DC-AC converter 3 in parallel with the AC power supply 1 via the direct feed circuit 6, and 15a is an inspection control for sending an inspection command signal to the output switch 5 and the AC switch 7. It is a device.

The output switch 5 and the AC switch are output in response to the inspection command signal from the inspection control device 15a while the power supply device is in a no-load state before operation, or during operation when the DC-AC converter 3 is supplying power to the AC load 8. 7 is closed at the same time, and the DC-AC converter 3 and the AC power supply 1 are operated in parallel via the direct feed circuit 6. Control of the parallel operation control device 11a is conventionally known as shown in, for example, Japanese Patent Application No. 4-130912, and therefore detailed description thereof will be omitted. However, by controlling the output frequency of the converter, The active power can be controlled. That is, by appropriately adjusting the output frequency of the converter, it is possible to regenerate a predetermined active power to the AC power supply 1.

In this case, since the predetermined DC power can be discharged from the storage battery 4 regardless of the presence or absence of the AC load 8 and the load amount, the operation of the storage battery abnormality detector 14a becomes stable,
It is possible to reliably detect the abnormality of the storage battery. If the storage battery 4 is inspected during load power supply and there is an abnormality,
Since the power supply from the AC power supply 1 to the AC load 8 is automatically continued via the direct-delivery circuit 6, there is no fear of interruption of the power supply to the load.

Example 5. This embodiment does not use the direct feed circuit 6 and is capable of surely detecting an abnormality regardless of the state and load amount of the AC load 8 as in the case of the fourth embodiment. The configuration is shown. In the figure, 2a is a converter such as a so-called high power factor converter capable of bidirectional power conversion, 10a is a control device for regenerating the converter 2a, and 15a is an inspection control device for sending an inspection command signal to 10a and 14a. Is. FIG. 7 is a circuit diagram showing details of the converter 2a, where 20 is an AC side terminal, 21 is a filter capacitor, 22 is a filter reactor, and 23-.
26 is a switching element such as a transistor, and 27 to 30.
Is a diode, and 31 is a DC side terminal.

In such a high power factor converter, the switching element is usually several tens to ten during one AC cycle.
PWM (pulse width modulation) for switching about 0 times
By controlling the current waveform on the AC side smoothly, you can freely convert power from either AC to DC (power running) or from DC to AC (regeneration) according to the current command. Can be done. Reference numerals 21 and 22 form a filter for removing a high frequency component caused by the switching frequency.

Therefore, in the case of a converter capable of only converting energy from AC to DC, for example, when the AC load 8 is a light load, a sufficient value cannot be selected as the discharge current of the storage battery 4, whereas in this embodiment Since a predetermined DC current can be discharged from the storage battery 4 regardless of the presence / absence of the AC load 8, the load amount, and the operation of the DC / AC converter 3, the operation of the storage battery abnormality detector 14 is stabilized, and the storage battery 4 It is possible to reliably detect the abnormality. Further, since the discharge current of the storage battery 4 can be fixed, the storage battery abnormality detector can be simplified.

In the fifth embodiment, in response to the inspection command signal from the inspection control device 15a, the bidirectional power conversion control circuit 10a causes the AC-DC converter 2a to supply the AC power source 1 with a predetermined power of the storage battery 4 as required. The storage battery 4 is operated to regenerate, and the storage battery abnormality is detected from the voltage and current of the storage battery 4 at this time.

Example 6. Next, an example of a case where the inspection is automatically performed at predetermined intervals during operation will be described with reference to FIG. In FIG. 8, 16 is a timer that determines the inspection cycle, 17 is a timer that operates when the charging time of the storage battery 4 continues for a predetermined value or more, and becomes 0 when a power failure is detected by a power failure detector not shown here. Reference numeral 15b, which is reset, is an inspection control device which sends an inspection command signal by a logical product from the timers 16 and 17. It is assumed that the timer 16 sends a signal at an interval that does not affect the start-up of the power supply device and the life of the storage battery 4 and that frequent failure detection can be performed. In addition, the timer 17 has a time limit that allows the storage battery 4 to be substantially fully charged.

Although the life of the storage battery generally becomes shorter as the number of discharges increases, in this embodiment, since the inspection is minimized, the influence on the life of the storage battery can be minimized. Moreover, since the inspection is automatically performed, the operator does not forget to perform the inspection, and the operation is reliable. Also, since a timer for monitoring the charging time is provided, there is no risk of erroneous detection of an abnormality even if the storage battery is discharged due to a power failure occurring immediately before the start of inspection. Although the timers 16 and 17 are used in the above embodiment, the configuration may be simplified by using only the timer 16.

Example 7. Next, an embodiment in which the capacity of the storage battery can be estimated from the storage battery discharge current and the storage battery voltage under inspection will be described with reference to FIG. In FIG. 9, reference numeral 18 denotes a storage battery capacity calculation device having a table for obtaining the storage battery capacity from the storage battery voltage when the storage battery 4 is discharged at a predetermined current for a predetermined time, and the calculated storage battery capacity is displayed on the display device 19. To do.

As shown in FIG. 10, in the table of the storage battery capacity calculating device 18, the capacity of the storage battery is calculated by previously inputting the relationship between the measured storage battery voltage and the estimated storage battery capacity for a predetermined discharge current. Can be easily obtained. Further, by comparing and displaying the storage battery capacity obtained from the measurement result and the capacity of the storage battery 4 actually used on the display device 19, the deterioration degree of the storage battery 4 can be known and it is effective for preventive maintenance of the device.

Example 8. Next, an embodiment in which the remaining life of the storage battery can be estimated from the estimated capacity of the storage battery obtained by the inspection of Embodiment 7 will be described with reference to FIG. In FIG. 11, reference numeral 18a denotes a storage battery capacity calculation device having a table for accurately obtaining the capacity of the storage battery by performing temperature correction from the storage battery voltage and the storage battery ambient temperature when the storage battery is discharged at a predetermined current. Battery capacity display device 1
Display on 9. Reference numeral 40 denotes a storage device that stores the output of the storage battery capacity calculation device 18a for each inspection, and can store data for the past several times. Reference numeral 41 is a remaining life estimation device that estimates the remaining life from the estimated capacity of the storage battery stored in the storage device 40.

The remaining life estimation device 41 approximates the estimated capacity of the storage battery obtained from the measurement results of the past several times by a multidimensional expression, and the remaining capacity of the storage battery (the capacity of the storage battery for judging the end of life) Estimate how long it will reach. This makes it possible to determine the replacement time of the storage battery, which is more effective for preventive maintenance of the device.

Example 9. In each of Examples 1 to 8 described above, the storage battery 4 was used as the energy storage means,
Needless to say, other energy storage means such as a condenser or a flywheel may be used, and the power conversion means may be another conversion means such as an AC-AC converter corresponding to the energy storage means, which has the same effect.

[0044]

As described above, according to the first aspect of the present invention, the power conversion means is controlled so that the energy storage means operates to release the energy. Therefore, the energy storage means can be inspected during the operation of the apparatus. Therefore, the reliability of the power supply device is improved.

Further, according to the second aspect of the present invention, the AC-DC converter is controlled to cause the storage battery to perform the discharging operation, and whether or not the storage battery is abnormal is detected from the output of the storage battery current and voltage detecting means. Accurate and reliable inspection of the storage battery can be performed while the device is operating.

According to the third aspect of the present invention, the DC-AC converter is controlled so that the storage battery is discharged to the AC power source via the direct transfer circuit. Therefore, the storage battery can be inspected regardless of the AC load state. Becomes

Further, according to the fourth aspect of the present invention, the AC-DC converter capable of bidirectional power conversion is controlled to discharge the storage battery to the AC power source in the regenerative mode. Instead, the storage battery can be inspected.

Further, according to the fifth aspect of the present invention, since it is determined that the storage battery is abnormal when the detected storage battery voltage exceeds the set range for the current, it is possible to reliably detect the abnormality of the storage battery. Become.

In the sixth aspect of the present invention, the discharge current or power is controlled to a predetermined value, and when the storage battery voltage exceeds a set range with respect to the discharge current or power after a predetermined time has elapsed from the start of discharge. Since the abnormality is determined, the detection conditions are standardized, and the abnormality detection operation becomes more stable and reliable, and the detection accuracy is improved.

Further, according to claim 7 of the present invention, the abnormality detection operation is canceled when the discharge has passed the set time or when the storage battery voltage has dropped below the set value. It is possible to surely prevent the influence on.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a power supply device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a storage battery current-voltage characteristic for explaining detection of a storage battery abnormality according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a discharge time-voltage characteristic for explaining detection of a storage battery abnormality according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a power supply device according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram showing a power supply device according to a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram showing a power supply device according to a fifth embodiment of the present invention.

7 is a circuit diagram showing an internal configuration of the bidirectional power converter of FIG.

FIG. 8 is a configuration diagram showing a power supply device according to a sixth embodiment of the present invention.

FIG. 9 is a configuration diagram showing a power supply device according to a seventh embodiment of the present invention.

FIG. 10 is a diagram showing characteristics of a table for obtaining a storage battery capacity from a storage battery voltage in Embodiment 7 of the present invention.

FIG. 11 is a configuration diagram showing a power supply device according to an eighth embodiment of the present invention.

FIG. 12 is a configuration diagram showing a conventional power supply device.

[Explanation of symbols]

1 AC power supply as a 1st power circuit 2 AC-DC converter as a power conversion means 3 DC-AC converter as a power conversion means 4 Storage battery 6 as an energy storage means 6 Direct transfer circuit 8 As a 2nd power circuit AC load 10,10a AC-DC converter control device 11,11a DC-AC converter control device 12 Current sensor as current / voltage detection means 13 Voltage sensor as current / voltage detection means 14,14a Storage battery as storage battery abnormality detection means Anomaly detector 15,15a, 15b Inspection control device

Claims (7)

[Claims] 1. A power conversion means for converting power from a first power circuit and supplying it to a second power circuit, and the first power circuit.
In a power supply device having energy storage means for storing energy by the power from the power circuit and replacing the abnormal state of the first power circuit as an input source of the power conversion means, the power conversion means is operated in a predetermined operation. A power supply device capable of detecting an abnormality in the energy storage means during power supply to the second power circuit by controlling the energy storage means to an energy release operation by controlling the state. 2. An AC-DC converter for converting AC power from an AC power source into DC power, a storage battery connected to the DC side of the AC-DC converter, and DC power connected to the storage battery to AC power. DC converted and supplied to AC load
In a power supply device equipped with an AC converter, a unit for detecting the current and voltage of the storage battery, and the AC-DC converter is controlled to a predetermined operating state while the DC-AC converter is in operation to control the storage battery. And a storage battery abnormality detecting means for detecting abnormality of the storage battery based on an output from the detecting means at the time of discharging. 3. An AC-DC converter for converting AC power from an AC power supply into DC power, a storage battery connected to the DC side of the AC-DC converter, and DC power connected to the storage battery for converting DC power to AC power. A DC-AC converter for supplying to an AC load, and a power supply device having a direct transfer circuit configured so that the AC power source and the AC load can be directly connected, means for detecting the current and voltage of the storage battery, and While the DC-AC converter is operating, the direct transfer circuit is configured to be closed, and the DC-AC converter is controlled to regenerate the electric power of the storage battery to the AC power source via the direct transfer circuit to control the storage battery. A power supply device comprising a storage battery abnormality detecting means for discharging and detecting an abnormality of the storage battery based on an output from the detecting means at the time of discharging. 4. An AC-DC converter which is connected to an AC power source and is capable of bidirectionally converting power between AC and DC.
In a power supply device including a storage battery connected to the DC side of the DC converter, and a DC-AC converter connected to the storage battery and converting DC power into AC power and supplying the AC load, current and voltage of the storage battery Means for detecting, and during the operation of the DC-AC converter, the AC-DC converter is controlled in a regenerative mode to the AC power source to discharge the storage battery, from the detecting means at the time of this discharge. A power supply device comprising storage battery abnormality detecting means for detecting an abnormality of the storage battery based on an output. 5. The storage battery abnormality detecting means determines that the storage battery is abnormal when the detected storage battery voltage exceeds a preset range for the storage battery current. The power supply device according to. 6. The storage battery abnormality detecting means controls the discharge current or the discharge power of the storage battery to a predetermined value, and the storage battery voltage detected after a predetermined time has elapsed from the start of the discharge corresponds to the storage battery current or the storage battery power being discharged in advance. The power supply device according to any one of claims 2 to 4, wherein the storage battery is determined to be abnormal when the set range is exceeded. 7. The storage battery abnormality detecting means releases the abnormality detection operation and charges the storage battery when the storage battery discharges for a preset time or when the detected storage battery voltage drops below a preset value. 7. The power supply device according to claim 2, wherein the power supply device is returned to operation.