JP2003070183A - Power outage back-up power source equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power source equipment for power outage back-up which can prevent a malfunction by a rapid voltage drop when a power source is switched in power outage and return of the power source. SOLUTION: The power outage back-up power source equipment comprises a power supply input voltage monitoring circuit which discriminates input of a commercial power supply to a main power supply circuit 3, a power supply output voltage monitoring circuit which discriminates the voltage level of a DC voltage fed from the main power supply circuit 3, a switching control means 8 which controls a connection of a back-up battery power supply 5 to an output terminal 2, and a power cut and power return control circuit 10 which connects the back-up battery power supply to the output terminal by closing the switching control means 8 when the input monitoring voltage of the power supply input voltage monitoring circuit is lower than the first voltage level and cuts off the connection between the back-up battery power supply 5 and output terminal 2 when the input monitoring voltage and output monitoring voltage of each power supply input voltage monitoring circuit and power supply output voltage monitoring circuit exceeds the first and second voltage levels.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a power failure backup power supply device having a function of supplying a direct current power source obtained by rectifying and converting a commercial power source at all times and switching to a backup battery at the time of power failure.

[0002]

2. Description of the Related Art Conventionally, in a power supply device having a function of switching to a backup battery at the time of power failure, the detection of power failure and power recovery is detected by either an input voltage or an output voltage.

[0003]

However, in monitoring only the output voltage, the output voltage drops when the output current is limited, so that it is determined that there is a power failure, and therefore the backup battery is switched to even when there is no power failure. When monitoring only the input voltage, it takes time to start the switching power supply and charge the capacitor when switching to the commercial power supply when the power is restored, so the output voltage does not rise sufficiently and the output voltage drops rapidly. There is a problem such as doing.

The present invention has been proposed to solve such a problem, and an object thereof is to prevent a malfunction due to an output voltage drop at the time of power supply switching at the time of power failure and power recovery of the power supply device. To provide a backup power supply.

[0005]

In order to achieve the above object, a power failure backup power supply device according to claim 1 is a DC power supply from a main power supply circuit obtained by rectifying and converting a power supply output from an output terminal into a commercial power supply. A backup battery power supply prepared in advance, and a power failure backup power supply device provided with a switching control means for automatically controlling switching between a normal time and a power failure, and has the following features.

That is, the switching control means uses a sub power supply circuit obtained by rectifying and converting a commercial power supply as a drive power supply, and inputs the power supply voltage supplied to the input side of the main power supply circuit to the main power supply circuit as an input monitoring voltage. The power supply input voltage monitoring circuit that determines whether the commercial power supply is turned on and the power supply voltage supplied to the output side of the main power supply circuit is used as the output monitoring voltage to determine the voltage level of the DC power supply output from the main power supply circuit. A power supply output voltage monitoring circuit, a switching control means for controlling at least the connection of the backup battery power supply to the output terminal, and an input monitoring voltage of the power supply input voltage monitoring circuit lower than a predetermined first voltage level. Is detected, the switching control means is closed to connect the backup battery power source to the output terminal, When the power supply input voltage monitoring circuit and the power supply output voltage monitoring circuit detect that the respective input and output monitoring voltages exceed the first voltage level and the predetermined second voltage level, the switching is performed. A power failure / recovery control circuit is provided which opens the control means and disconnects the connection between the backup battery power source and the output terminal.

According to a second aspect, in the first aspect, the switching control means includes a first switching element provided on the main power supply circuit side and a second switching element provided on the backup battery power supply side. When the power failure / recovery control circuit detects that the input monitoring voltage of the power supply input voltage monitoring circuit is lower than the first voltage level, the first switching element is opened and the first switching element is opened. The switching battery 2 is closed and the backup battery power source is connected to the output terminal, while the power source input voltage monitoring circuit and the power source output voltage monitoring circuit have the respective input and output monitoring voltages as the first voltage. Level, when it is detected that a predetermined second voltage level is exceeded, the first switching element is closed and the second switch is closed. Open grayed device, the main power supply circuit, characterized in that connected to the output terminal.

According to a third aspect of the present invention, in the power failure / restoration control circuit according to any one of the first and second aspects, the power supply input voltage monitoring circuit and the power supply output voltage monitoring circuit monitor respective inputs and outputs. After detecting that the voltage exceeds the first voltage level and the second voltage level and closing the switching control means, the input monitoring voltage of the power supply input voltage monitoring circuit is changed to the first monitoring voltage. It has a latch function that holds the closing operation unless the voltage level of the device is lowered.

According to a fourth aspect of the present invention, in the third aspect, the power failure / recovery control circuit includes a thyristor, and the thyristor has an input monitoring voltage of the power supply input voltage monitoring circuit at the first voltage level. The first that becomes conductive when crossed
Second photocoupler which is turned on when the power supply voltage of the sub power supply circuit is supplied between the anode and the cathode and the output monitoring voltage of the power supply output voltage monitoring circuit exceeds the second voltage level. Thus, the power supply voltage of the sub power supply circuit is supplied to the gate trigger circuit and driven.

According to a fifth aspect of the present invention, in the first to fourth aspects, the backup battery power source is a storage battery that can be reused by charging, and is constantly charged by a charging power source circuit obtained by rectifying and converting the commercial power source. It has become.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit block diagram showing a configuration example of a power failure backup power supply device of the present invention.

In the figure, 1 is a commercial power supply input terminal, 2 is an output terminal, 3 is a main power supply circuit for rectifying and converting a commercial power supply, and 4 is for rectifying and converting a commercial power supply. Sub-power supply circuit, 5 is a backup battery power supply that supplies DC power to the load in the event of a power failure, 6 is a charging power supply circuit that rectifies and supplies commercial power to charge the backup battery power supply 5, and 7 is switching control means 8 is a switching circuit for switching control, and 10 is a power failure /
The power recovery control circuit is shown. In addition, D. B. Is a full-wave rectifier circuit, D, D1 and D2 are diodes, C is a smoothing capacitor, T is a transformer, and f is a fuse.

The power failure / power recovery control circuit performs the following basic operation.

That is, during normal operation without power failure, the commercial power input from the commercial power input terminal 1 is the diode bridge D. B. After being full-wave rectified by the main switching circuit including the switching transformer T, the direct current is DC converted by the rectifying and smoothing circuit including the diode D, the reactor, and the smoothing capacitor C provided on the secondary side of the transformer T. When the power is output to the load from the output terminal 2 through the diode D1 and a power failure occurs, a switching signal is sent from the power failure / recovery control circuit 10 shown in detail in FIG. 2 to the switching circuit 7 to configure the switching control means. FET8 to do
Is turned on, the battery power of storage battery 5 is diode D
2 is output to the load from the output terminal 2, the load output at the time of power failure is backed up, and when power is restored, a switching signal is sent from the power failure / power recovery control circuit 10 to the switching circuit 7, and the FET 8 constituting the switching control means. Is turned off, so
The output of the storage battery 5 is cut off, and the rectified and converted DC power is again output to the load from the output terminal 2 through the diode D1.

As shown in the figure, this power supply device uses a storage battery 5 as a backup battery power supply, and the storage battery 5 is constantly charged by a charging power supply circuit 6 that rectifies and outputs a commercial power supply. It is configured to

FIG. 2 is a circuit block diagram showing a main configuration of the power failure / power recovery control circuit 10.

In the figure, A is a power supply input voltage monitoring circuit, and the sub power supply is controlled by the conduction control of the first photocoupler 11 which is controlled by the shunt control element 12 having the first voltage level Vth1 as a threshold value. A power supply rectified and converted by the circuit 4 is supplied between the anode and the cathode of the thyristor 17, B is a power supply output voltage monitoring circuit, and shunt control using the second voltage level Vth2 as a threshold value. By the second photocoupler 13 whose conduction is controlled by the element 14, the DC power source rectified and converted from the main power source circuit 3 is supplied to the gate trigger generation circuit 16, and the gate trigger pulse is output to drive the thyristor. ing.

The thyristor 17, the gate trigger generating circuit 16 composed of a resistor and a capacitor, and the third photocoupler 15 driven by the thyristor 17 constitute a thyristor latch circuit. The gate trigger generation circuit 16 is driven by the second photocoupler 13 controlled by the shunt control element 14.

The third photocoupler is conductively controlled by the turn-on / off operation of the thyristor 17. In the conductive state, a switching signal is sent to the switching circuit 7 to open the FET 7 and supply the DC power from the main power supply circuit 3. Shut off,
In the non-conducting state, the FET 7 is closed to supply the DC power from the backup battery 5.

A first photocoupler 11 controlled by the shunt control element 12 is connected to the anode side of the thyristor 17.

The output voltage of the main power supply circuit 3 which is full-wave rectified is the threshold value of the shunt control element 14, the second level V.
When th2 is exceeded, the photocoupler 13 becomes conductive and the rectified power from the sub power supply circuit 4 is applied to the gate trigger generation circuit 16, so that a gate pulse is applied to the gate of the thyristor 17.

When the input voltage of the main power supply circuit 3 exceeds the first level Vth1, the first photocoupler 11 becomes conductive and the rectifier power supply from the sub power supply circuit 4 is applied to the anode side of the thyristor 17.

The thyristor 17 is turned on at the time when the gate pulse is received in the state where the rectified power supply of the sub power supply circuit 4 is applied to the anode side, and after the turn-on, the holding current is passed through the thyristor 17. As long as the turn-on state is maintained, if the input voltage of the main power supply circuit 3 falls below the first level Vth1, the first
Since the photocoupler 11 becomes non-conductive and the holding current flowing in the thyristor 17 is cut off, the thyristor 17 turns off and the third photocoupler 15 also becomes non-conductive.

Then, based on the above basic operation principle,
The normal operation of the power failure / power recovery control circuit 10 will be described.

When the DC voltage that is full-wave rectified by the sub power supply circuit 4 exceeds a predetermined first voltage level Vth1 (for example, about 100 V DC) of the first shunt control element 12, the first photocoupler 11 becomes conductive. Therefore, a voltage is applied between the anode and cathode of the thyristor 17.

In this state, the full-wave rectified DC voltage of the main power supply circuit 3 becomes the second shunt control element 14
A predetermined second voltage level Vth2 (eg DC about 20
V) is exceeded, the second photocoupler 13 becomes conductive and a voltage is applied to the gate trigger circuit 16 to generate a gate trigger pulse. Therefore, the thyristor 17 turns on, the third photocoupler 15 becomes conductive, and the FET 7 is turned on. Turn off.

As a result, the DC power supply from the backup battery 5 is cut off to the load, and the full-wave rectified DC voltage of the commercial power supply is supplied from the main power supply circuit 3 through the output terminal 2.

As long as the holding current is maintained even if the voltage level drops due to overcurrent, the thyristor 17
Holds turn-on, so that state is maintained.

Next, the operation at the time of power failure will be described.

When a power failure occurs and the half-wave rectified DC voltage of the sub power supply circuit 4 falls below a predetermined first voltage level Vth1 of the first shunt control element 12, the first photocoupler 11 is deactivated. The thyristor 17 is turned on because the holding current does not flow in the thyristor 17 because it becomes conductive. When the thyristor 17 turns off, the third photocoupler 15 also becomes non-conductive, the FET 7 turns on, and the DC power from the backup battery 5 is supplied to the load.

Next, the operation at power recovery will be described.

When the power is restored, the half-wave rectified DC voltage of the sub power supply circuit 10 is applied between the anode and the cathode of the thyristor 17. At that time, the full-wave rectified DC voltage of the main power supply circuit 3 becomes Second shunt control element 1
2 does not exceed the second voltage level Vth2, the second photocoupler 11 becomes non-conductive, and therefore no voltage is applied to the gate trigger circuit 16, so that no gate trigger pulse is generated and the thyristor 17 turns on. do not do.

However, after that, the main power supply circuit 3
When the full-wave rectified DC voltage of exceeds the second voltage level Vth2 of the second shunt control element 13, the second photocoupler 11 is turned on and a voltage is applied to the gate trigger circuit 16, so that the gate trigger When a pulse is generated, the thyristor 17 turns on, and the normal operation is performed.

FIG. 3 shows a time chart for explaining the control operation at power failure and power recovery.

(A) is a commercial AC power supply voltage applied to the commercial power supply input terminal, (b) is an input voltage of the power supply input voltage monitoring circuit, (c) is an output voltage of the power supply input voltage monitoring circuit,
(D) shows the current flowing through the thyristor latch circuit, (e) shows the input voltage of the power supply output voltage monitoring circuit, and (f) shows the operation of the thyristor latch circuit. In addition, (a) ~
Regarding the waveform diagram of (e), the corresponding parts in FIGS. 1 and 2 are shown by adding the symbols (a) to (e).

According to the configuration using such a thyristor latch circuit, once the thyristor turns, even if a sudden voltage drop due to an overcurrent occurs in the output voltage due to a change in load or the like, the holding current of the thyristor is reduced. As long as the above is ensured, the load will be a power source obtained by converting a commercial power source into a direct current.

Further, in this method, the commercial power supply reaches a sufficient level as compared with the switching timing (FIGS. (I) and (j)) in the conventional power failure / power recovery method in which the input voltage is monitored and controlled. Since power is restored at the time of power recovery, it is possible to suppress an effect such as a sudden voltage drop at power recovery and making the load unstable ((g), (h) and (i)). , (J) comparison).

In the above embodiments, the example in which the switching control means is constituted by using one FET is shown, but two switching elements are provided on each of the main power supply circuit 3 side and the sub power supply circuit 4 side. May be.

In this case, when the power failure / recovery control circuit detects that the input monitoring voltage of the power supply input voltage monitoring circuit is lower than the first voltage level, the first switching element is opened and the second switching element is opened. While the element is closed and the backup battery power supply is connected to the output terminal, the power supply input voltage monitoring circuit and the power supply output voltage monitoring circuit have respective inputs,
When it is detected that the output monitoring voltage exceeds the first voltage level or the predetermined second voltage level, the first switching element is closed, the second switching element is opened, and the main power supply circuit is connected to the output terminal. Connecting.

[0041]

As can be understood from the above description, according to the power failure backup power supply device of the first aspect, the backup operation at the time of power failure is quick and the operation at power recovery is stable. If a power failure occurs and the voltage level of the commercial power supply input to the main power supply circuit drops, the power will be switched to the backup power supply instantly.When the power is restored, even if the commercial power supply is turned on, the main power supply circuit will As long as the output DC power does not rise to a stable level, the backup battery power supply is maintained, and if the DC power from the main power circuit rises to a stable level, the commercial power is immediately switched to the rectified DC power. Is output.

In the second aspect, the switching control means is
Since the main power supply circuit side and the sub power supply circuit side each include the first and second switching elements, both the first and second switching elements should be open when the power supply device is not used. For example, even if the commercial power supply is not cut off, the output of the power supply can be prohibited and held, so that it is not necessary to separately provide a switching element.

According to the present invention, since the latch function is provided, even if the DC power output from the main power supply circuit is temporarily lowered due to overcurrent or the like, as long as there is no power failure,
Since the output of direct current is not interrupted, the operation is stable and highly reliable.

In the fourth aspect, since the power failure / recovery control circuit is configured by using the thyristor and the photo coupler, the backup operation at the time of power failure is quick and the operation at the time of power recovery is stable with a simple component configuration. It is possible to realize a backup power supply unit that has achieved blackout.

In claim 5, the backup battery power source is
It is composed of a storage battery that can be reused by charging, and is constantly charged by a charging power circuit that rectifies and converts commercial power, so there is no concern that the backup power will be cut off during a power failure, and the reliability of the backup power supply device. Can be increased.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a configuration example of a power failure backup power supply device of the present invention.

FIG. 2 is a view of a power failure backup power supply device of the present invention,
FIG. 3 is a circuit block diagram showing a main configuration of a power failure / power recovery control circuit.

FIG. 3 is a time chart for explaining a power failure and power recovery control operation.

[Explanation of symbols]

1 Commercial power input terminal 2 output terminals 3 Main power circuit 4 sub power supply circuit 5 backup power supply battery 6 Power supply circuit for charging 7 Switching circuit 8 FET (switching control means) 10 Power failure / power recovery control circuit A Power input voltage monitoring circuit B Power output voltage monitoring circuit 11 First Photocoupler 12 First shunt control element 13 Second photo coupler 14 Second shunt control element 15 Third Photocoupler 16 Gate trigger circuit 17 Thyristor

Claims (5)

[Claims] 1. A power source output from an output terminal is automatically switched between a direct current power source from a main power source circuit obtained by rectifying and converting a commercial power source and a backup battery power source prepared in advance during normal operation and power failure. In the power failure backup power supply device having a switching control means, the switching control means uses a sub-power supply circuit that is rectified and converted from a commercial power supply as a drive power supply, and the power supply voltage supplied to the input side of the main power supply circuit is an input monitoring voltage. As a power supply input voltage monitoring circuit that determines whether the commercial power supply input to the main power supply circuit is turned on, and a power supply voltage supplied to the output side of the main power supply circuit as an output monitoring voltage A power supply output voltage monitoring circuit that determines the voltage level of the power supply, and a switch that controls at least the connection of the backup battery power supply to the output terminal. When it is detected that the input control voltage of the switching control means and the power supply input voltage monitor circuit is lower than a predetermined first voltage level,
The switching control means is closed to connect the backup battery power supply to the output terminal, while the power supply input voltage monitoring circuit and the power supply output voltage monitoring circuit have respective input and output monitoring voltages of the first voltage. And a power failure / recovery control circuit for opening the switching control means and disconnecting the backup battery power source and the output terminal when it is detected that the level exceeds a predetermined second voltage level. A power failure backup power supply device characterized in that 2. The switching control means according to claim 1, further comprising a first switching element provided on the main power supply circuit side and a second switching element provided on the backup battery power supply side, The power failure / recovery control circuit opens the first switching element and detects the second switching when the input monitoring voltage of the power supply input voltage monitoring circuit is detected to be lower than the first voltage level. While closing the element and connecting the backup battery power supply to the output terminal, the power supply input voltage monitoring circuit,
When the power supply output voltage monitoring circuit detects that the input and output monitoring voltages exceed the first voltage level and the predetermined second voltage level, the first switching element is closed, A power failure backup power supply device characterized by opening the second switching element and connecting the main power supply circuit to the output terminal. 3. The power failure / recovery control circuit according to claim 1, wherein the power supply input voltage monitoring circuit and the power supply output voltage monitoring circuit have respective inputs and output monitoring voltages. After detecting that the first voltage level and the second voltage level are exceeded and closing the switching control means, the input monitoring voltage of the power supply input voltage monitoring circuit is changed to the first voltage level. A power outage backup power supply that has a latch function that holds the closing action unless the power is lowered. 4. The power failure / recovery control circuit according to claim 3, further comprising a thyristor, wherein the thyristor is provided when an input monitoring voltage of the power supply input voltage monitoring circuit exceeds the first voltage level. When the power supply voltage of the sub power supply circuit is supplied between the anode and the cathode by the first photocoupler that is conductive to the second power supply and the output monitoring voltage of the power supply output voltage monitoring circuit exceeds the second voltage level. A power failure backup power supply device in which the power supply voltage of the sub power supply circuit is supplied to and driven by the gate trigger circuit by a second photocoupler that conducts. 5. The backup battery power source according to any one of claims 1 to 4, wherein the backup battery power source is composed of a rechargeable storage battery and is constantly charged by a charging power source circuit obtained by rectifying and converting the commercial power source. There is a power outage backup power supply.