JP3139193B2 - Power supply - Google Patents

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, particularly an AC / DC converter, and a storage battery connected to the DC side thereof.
The present invention relates to a power supply device having a DC-AC converter connected to the storage battery.

[0002]

2. Description of the Related Art Conventionally, an uninterruptible power supply which combines a storage battery and an inverter and can supply power to a load even when the supply of energy from another source is cut off is well known. Such an uninterruptible power supply device is used to configure a power supply system that supplies power to a load requiring continuous operation, such as a computer, even when a power failure occurs in a power system. You.

FIG. 12 shows, for example, “Uninterruptible power supply (UP
FIG. 28 is a configuration diagram showing the conventional uninterruptible power supply device shown in FIG. 2.8 on page 58 of “S) Introduction of actual battle guide” (published by Denki Shoin Co., Ltd. on Feb. 25, 1989). 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 for inversely converting 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, 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. This is the AC load of 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 to float (float) charge the storage battery 4 and to make the DC-AC converter 3 stable AC. The power is inverted and supplied to the AC load 8 via the output switch 5. When the AC power supply 1 is out of power, the storage battery 4 discharges the DC power and supplies the DC power to the DC-AC converter 3 to continue the power supply to the AC load 8. When an overcurrent exceeding the rating of the DC-AC converter 3 flows into the AC load 8 or the DC-AC converter 3 breaks down, the AC power of the AC power supply 1 is supplied via the direct feed circuit 6 and the AC switch 7. Is supplied directly to the AC load 8.

[0005]

Since the conventional uninterruptible power supply is constructed as described above, it operates (floating charge).
Even if an abnormality (failure) occurs in the storage battery 4 during that time, it cannot be detected, and the failure becomes apparent only when the uninterruptible power supply enters a required input power failure state, and the AC load 8 is continuously supplied. There was a fatal problem as an uninterruptible power supply that it would not be possible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a highly reliable power supply device by enabling the storage battery to be inspected during operation of the device and detecting the abnormality in advance. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION The power supply device according to the invention, means for detecting the current and voltage of the storage battery, and DC - during operation of the AC converter, AC - stop operation of the DC converter
Shutdown, or the discharge current or power of the storage battery
Base is controlled to so that to discharge the storage battery, the configuration with a battery abnormality detection means for detecting the original on the battery abnormality output from the detection means at the time of the discharge
It was made .

[0008] The power supply according to the present invention, means for detecting the current and voltage 蓄 battery, and DC - during operation of the AC converter, and closing the direct circuit, the power of the storage battery through the direct circuit A storage battery abnormality detecting means for controlling the DC-AC converter to regenerate the AC power to discharge the storage battery and detecting an abnormality of the storage battery based on an output from the detection means at the time of discharging; Things.

[0009] The power supply device according to the present invention is configured to determine that the storage battery is abnormal when the detected storage battery voltage exceeds a predetermined range with respect to the storage battery current.

[0010] The power supply device according to the present invention also controls the discharge current or discharge power of the storage battery to a predetermined value, and the storage battery voltage detected after a lapse of a predetermined time from the start of discharge is smaller than the storage battery current or storage battery power during discharge. When the value exceeds a preset range, it is determined that the storage battery is abnormal.

[0011] The power supply device according to the present invention also releases the abnormality detection operation when the discharge of the storage battery has elapsed for a predetermined time or when the detected storage battery voltage has fallen below a predetermined value. Is returned to the charging operation.

[0012]

In the power supply device according to the present invention, when the AC-DC converter is controlled to a predetermined operating state, for example, when it is stopped, the storage battery is discharged to the AC load via the DC-AC converter. It is based on judging the presence or absence of abnormality of the storage battery from the current and voltage characteristics .

[0013] In the power supply device according to the present invention, its DC - is regenerated electric power of the storage battery by controlling the AC converter to the AC power source through the direct circuit current at that time, the abnormal presence or absence of the battery voltage characteristics Can be determined.

Further, in the power supply device according to the present invention, upon detecting an abnormality of the storage battery, it is determined whether the detected storage battery voltage exceeds a set range with respect to the current, or after a lapse of a predetermined time from the start of discharging. Is determined by whether or not the storage battery voltage exceeds the set range with respect to current or power.

Further, in the power supply device according to the present invention, when the discharge has passed the set time or when the storage battery voltage has fallen below the set value, the abnormality detecting operation is canceled to prevent abnormal discharge due to inspection.

FIG. 1 is a block diagram showing a power supply device serving as a base of the present invention. Further, reference numeral 10 denotes a control device of the AC-DC converter 2, 1
1 is a control device for the DC-AC converter 3, 12 is a current sensor for measuring the discharge current of the storage battery 4, 13 is a voltage sensor for measuring the voltage of the storage battery 4, and 14 is the storage battery 4 based on the values measured by both sensors 12, 13. Battery abnormality detector for detecting abnormality of the battery and sending an abnormality signal;
0, 11 is an inspection control device that sends a command signal to the storage battery abnormality detector 14.

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,
The operation of inversely converting the AC power 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 operation. At this time, the storage battery 4 is in a floating charge state.

Here, when the inspection control signal is sent from the inspection control device 15 during the operation of the power supply device, 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 charge state to the discharge 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 corresponding to the storage battery current measured by the current sensor 12, but the storage battery 4 has failed 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 transmits an abnormality signal.

FIG. 2 is a characteristic diagram showing the relationship between the storage battery current and the storage battery voltage. If the storage battery is in a normal range, the voltage decreases with respect to the current in accordance with the state of charge of the storage battery. 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 the relationship between the storage battery current and the storage battery voltage is within a normal range. An abnormality can be detected. In this device , by simulating the input power failure state as described above, the storage battery 4
Abnormality can be detected in advance. 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. In addition, even when power is being supplied to the AC load 8, if there is an abnormality in the storage battery, the AC-DC converter 2 can be immediately restarted to avoid affecting the AC load 8.

[0020]

[Embodiment 1 ] Next, a description will be given of a first embodiment of the present invention in which the discharge of the storage battery 4 is controlled to a certain condition so that abnormality detection can be performed more stably and reliably. Since the overall configuration is the same as that shown in FIG. 1, the description is omitted.

Next, the operation will be described. During operation of the DC-AC converter 3, the control device 10 of the AC-DC converter controls the AC-DC converter 2 according to the inspection command signal from the inspection control device 15, and the storage battery 4 is discharged at a predetermined current value. 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 corresponding to the storage battery current measured by the current sensor 12; If the battery has failed or has not been sufficiently charged for some reason, the storage battery voltage has 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 at 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 greater. 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 a predetermined time after the start of the discharge control, and determines whether or not the capacity of the storage battery is in a normal range. This makes it possible to detect a storage battery abnormality.
As described above, by performing the discharge controlled to the predetermined current value, the condition for judging the presence or absence of abnormality in the storage battery abnormality detector 14 is standardized, and the operation becomes more stable and reliable. In the above description, the current during discharge is controlled to be constant, but the discharge power may be controlled to be constant.

Embodiment 2 FIG. Next, a power supply device according to a second embodiment of the present invention will be described. In this embodiment, means for more reliably preventing the inspection operation of the storage battery 4 performed during operation of the apparatus from affecting the AC load 8 is added, and FIG. 4 shows the configuration.
What is different from that of FIG. 1 is a storage battery abnormality detector 14a, which has a new voltage drop detection function. If the storage battery voltage drops to an abnormal level before time t1, an abnormal signal is generated and inspection control is performed. A check stop signal is sent to the device 15.

Next, the operation will be described. During operation of the DC-AC converter 3, the control device 10 of the AC-DC converter controls the AC-DC converter 2 according to the inspection command signal from the inspection control device 15, and the storage battery 4 is discharged at a predetermined current value. 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 corresponding to the storage battery current measured by the current sensor 12; If the battery has failed or has not been sufficiently charged for some reason, the storage battery voltage drops sharply before reaching time t1, and although not shown in FIG. There is a possibility that the DC voltage of the device set to a low voltage value may be reduced to a low voltage protection level. 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, the operation returns to the normal operation, so that there is no possibility that an abnormality occurs in the apparatus, and the power supply to the AC load 8 can be stably continued.

It should be noted that the abnormal voltage level at the time of instructing the stop of the inspection described above is set to a value equal to 0% and a value slightly lower than the battery voltage corresponding to the maximum value of the battery current in FIG. You may make it. Further, after a predetermined set time has elapsed after the start of the discharge, the check may be stopped and the operation may be returned to regardless of the storage battery voltage.

Embodiment 3 FIG. Next, a third embodiment in which an abnormality can be reliably detected regardless of the state of the AC load 8 and the load amount will be described with reference to FIG. In FIG. 5, reference numeral 11a denotes 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 reference numeral 15a denotes inspection control for sending an inspection command signal also to the output switch 5 and the AC switch 7. Device.

The output switch 5 and the AC switch are operated in response to a check command signal from the check control device 15a during a no-load state before the operation of the power supply device or during an operation in which the DC-AC converter 3 supplies power to the AC load 8. 7 are 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. The control of the parallel operation control device 11a is conventionally known as shown in Japanese Patent Application No. 4-130912, and will not be described in detail. However, by controlling the output frequency of the converter, the output is controlled. Active power can be controlled. That is, by appropriately adjusting the output frequency of the converter, predetermined active power can be regenerated to the AC power supply 1.

In this case, a predetermined DC power can be discharged from the storage battery 4 irrespective of the presence or absence of the AC load 8 and the load amount, so that the operation of the storage battery abnormality detector 14a is stabilized,
Abnormality of the storage battery can be reliably detected. If the storage battery 4 is found to be abnormal during the load power supply,
Since the power supply from the AC power supply 1 to the AC load 8 is automatically continued via the direct feed circuit 6, there is no possibility that the power supply to the load is interrupted.

Note that the embodiment does not use the direct sending circuit 6 and
3 Like the AC load 8 state, FIG. 6 a circuit configuration capable of reliably abnormality detection regardless of the load amount, in FIG. 7
Shows you. In the figure, 2a is a converter capable of bidirectional power conversion such as a so-called high power factor converter, 10a is a control device for regenerating the converter 2a, 15a is 10a, 14
This is an inspection control device that sends an inspection command signal to a. FIG.
Is a circuit diagram showing details of the converter 2a, 20 is an AC side terminal, 21 is a filter capacitor, 22 is a filter reactor, 23 to 26 are switching elements such as transistors, 27 to 30 are diodes, and 31 is a DC side terminal. It is.

In such a high power factor converter, the switching element normally has several tens to 10
PWM (pulse width modulation) that performs switching about 0 times
, The current waveform on the AC side can be controlled smoothly, and the power can be freely converted in both directions from AC to DC (power running) or from DC to AC (regeneration) according to the current command. Can be done. Reference numerals 21 and 22 constitute filters for removing high-frequency components caused by the switching frequency.

[0031] Therefore, if the transducer can only energy conversion from AC to DC, compared for example to the AC load 8 does not choose a sufficient value as the discharge current of the battery 4 in the case of light load, in the circuit Since a predetermined DC current can be discharged from the storage battery 4 irrespective of the presence or 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, Abnormality can be reliably detected. Further, since the discharge current of the storage battery 4 can be fixed, the storage battery abnormality detector can be simplified.

In the circuit shown in FIG . 6, in response to an inspection command signal from the inspection controller 15a, the bidirectional power conversion control circuit 10a controls the AC-DC converter 2a to supply predetermined power of the storage battery 4 as necessary to the AC power source 1a. The storage battery 4 is operated to regenerate the current, and the storage battery abnormality is detected from the voltage and current of the storage battery 4 at this time.

Embodiment 5 FIG. Next, an example in which the inspection is automatically performed at predetermined intervals during operation will be described with reference to FIG. In FIG. 8, reference numeral 16 denotes a timer for determining an inspection cycle, and 17 denotes a timer which operates when the charging time of the storage battery 4 has continued for a predetermined value or more, and is reset to 0 when a power failure detector (not shown) detects a power failure. Reset, 15b is the timer 16
This is an inspection control device that sends an inspection command signal by a logical product of AND and 17. The timer 16 sends a signal at the time of starting the power supply device and at an interval that does not affect the life of the storage battery 4 and that can frequently detect a failure. 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 is usually shortened as the number of discharges increases, in this embodiment, the inspection is minimized, so that the influence on the life of the storage battery can be minimized. Since the inspection is performed automatically, the operator does not forget to perform the inspection, and the operation is reliable. Further, since a timer for monitoring the charging time is provided, there is no possibility of erroneously detecting an abnormality even when a power failure occurs immediately before the start of inspection and the storage battery is discharged. Although the timers 16 and 17 are used in the above embodiment, the configuration may be simplified by using only the timer 16.

Embodiment 6 FIG. 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 during 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 calculating the storage battery capacity from the storage battery voltage when the storage battery 4 is discharged for a predetermined time at a predetermined current, and the calculated storage battery capacity is displayed on a display device 19. I do.

As shown in FIG. 10, the relationship between the measured storage battery voltage and the estimated storage battery capacity for a predetermined discharge current is input to the table of the storage battery capacity calculation device 18 in advance. 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 degree of deterioration of the storage battery 4 is known, which is effective for preventive maintenance of the device.

Embodiment 7 FIG. 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 in the sixth embodiment 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 calculating the storage battery capacity 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. The storage battery capacity is displayed on the display device 19. Reference numeral 40 denotes a storage device for storing the output of each inspection performed by the storage battery capacity calculation device 18a, and can store data several times in the past. Reference numeral 41 denotes a remaining life estimating device for estimating the remaining life from the estimated capacity of the storage battery stored in the storage device 40.

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

[0039]

As is evident from the foregoing description, according to the present invention, the AC - controls the DC converter and the storage battery to the discharge operation, by detecting the abnormal presence or absence of the battery from the output of the detection means of the battery current and voltage the inspection of the storage battery during operation of the device accurately, reliably have rows, it is based on improving the reliability of the power supply.

According to this invention, the DC - since so as to discharge AC converter controlled through the direct circuit to the AC power supply to the storage battery, inspection of the battery is made possible regardless of the state of the AC load.

Further, according to the present invention, when the detected storage battery voltage exceeds the set range with respect to the current, it is determined that the storage battery is abnormal, so that the storage battery abnormality can be reliably detected.

Further, according to the present invention, the discharge current or the power is controlled to a predetermined value, and when the storage battery voltage exceeds a set range with respect to the discharge current or the power after a lapse of a predetermined time from the start of the discharge, it is determined that the storage battery is abnormal. Since the determination is made, the detection conditions are standardized, the operation of abnormality detection becomes more stable and reliable, and the detection accuracy is improved.

Further, according to 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. The influence can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a power supply device serving as a base of the present invention.

FIG. 2 is a diagram showing storage battery current-voltage characteristics for explaining detection of a storage battery abnormality in the circuit of FIG . 1 ;

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

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

FIG. 5 is a configuration diagram showing a power supply device according to Embodiment 3 of the present invention.

FIG. 6 is a configuration diagram illustrating an example of a power supply device that does not use a direct transmission circuit .

FIG. 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 Embodiment 5 of the present invention.

FIG. 9 is a configuration diagram showing a power supply device according to Embodiment 6 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 6 of the present invention.

FIG. 11 is a configuration diagram showing a power supply device according to Embodiment 7 of the present invention.

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

[Explanation of symbols]

REFERENCE SIGNS LIST 1 AC power supply, 2 AC-DC converter, 3 DC-AC converter, 4 storage battery, 6 direct feed circuit, 8 AC load, 10, 10 a AC-DC converter control device, 11, 11 a DC-AC converter control device , 12 current sensor, 13 voltage sensor, 14, 14a storage battery abnormality detector, 15, 15a, 15b inspection control device.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-56043 (JP, A) JP-A-62-277026 (JP, A) JP-A-4-58739 (JP, A) JP-A-5-57039 30678 (JP, A) JP-A-2-103746 (JP, U) JP-B-52-42454 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02J 9/00-11 / 00

Claims (4)

(57) [Claims] 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 converting DC power to AC power connected to the storage battery. A DC-AC converter for supplying the AC load to the AC load, and a power supply device including a direct-feed circuit configured to directly connect the AC power supply and the AC load, wherein a means for detecting a current and a voltage of the storage battery; and During operation of the DC-AC converter, the direct-feed circuit is closed, and the DC-AC converter is controlled to regenerate the power of the storage battery to the AC power supply via the direct-feed circuit to discharge the storage battery. And a storage battery abnormality detecting means for detecting abnormality of the storage battery based on an output from the detection means at the time of discharging. 2. A battery abnormality detection means detects the battery voltage according to claim 1 Symbol placement of the power supply is characterized in that so as to determine preset range and the battery abnormality when exceeded against battery current . 3. The storage battery abnormality detection means controls the discharge current or discharge power of the storage battery to a predetermined value, and the storage battery voltage detected after a lapse of a predetermined time from the start of discharging is determined in advance with respect to the storage battery current or storage battery power being discharged. claim 1 Symbol placement of the power supply is characterized in that so as to determine the battery abnormality when exceeding the set range. 4. The storage battery abnormality detection means releases the abnormality detection operation and charges the storage battery when the discharge of the storage battery has elapsed for a preset time or when the detected storage battery voltage has dropped below a preset value. claim 1 Symbol placement of the power supply is characterized in that so as to return to operation.