JPH0837740A - Power supply backup device - Google Patents

Abstract

PURPOSE:To always secure the function of a backup power source by making either a first battery or second battery to discharge electricity to a discharge circuit by controlling a load switching circuit and measuring and recording the charging and discharging characteristics of the battery when commercial AC power supply is normal. CONSTITUTION:A power supply backup circuit 5 is provided with batteries 5a and 5b, their battery charging circuits 5c and battery voltage monitoring circuits 5d, a charging switching circuit 5e which switches the circuits 5 to each other and voltage monitoring switching circuit 5f which switches the terminal voltages of the batteries by using one circuit 5d, a battery discharging circuit 5g, load switching circuits 5h and 5i, control circuit 5j which outputs control signals CNT1-CNT7, and reverse-current preventing diodes D2-D4. The functional test of each battery is performed while the other battery is used and the time for the terminal voltage of the battery to reach a specific value is recorded. The characteristic test of each battery is performed at intervals of two weeks to several months. Therefore, a power supply backup device can be activated by always recognizing the states of the batteries and the function of the device as a backup power source can be secured always.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises an AC-DC converter for converting a constant-voltage DC power supply using a commercial AC power supply as an input, and a power failure occurs when the power from the AC-DC converter is supplied to a load circuit. For example, the present invention relates to a power backup device that backs up when the commercial AC power is cut off.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing a conventional power source backup device. In FIG. 6, 1 is an input plug of a commercial AC power supply, 2 is an AC-DC converter that converts the commercial AC power supply 1 into a constant-voltage DC power supply, and 3 is driven by a constant-voltage DC power supply from an AC-DC converter 2. Load circuits 4 to 4 for supplying power for driving the load circuit 3 when the commercial AC power supply is cut off, D1 to D3
Indicates a backflow prevention diode.

Here, the power source backup circuit 4 is
AC-DC converter 2 when commercial AC power is cut off
4a that supplies power to the load circuit 3 instead of
When the commercial AC power supply is normal, the battery charging circuit 4b for charging the battery 4a via the diode D2 and the terminal voltage of the battery 4a are monitored, and when the terminal voltage exceeds a certain value. A battery voltage monitoring circuit 4c having a function of instructing the battery charging circuit 4b to temporarily suspend charging and the backflow prevention diodes D2 and D3 are provided.

In the above structure, the battery voltage monitoring circuit 4c is used for charging the battery 4a in a short time, but the battery 4a requires about 1 day to a dozen or more hours.
It is not used when the circuit is configured to charge the. Normally,
Power is supplied from the AC / DC converter 2 to the load circuit 3 via the diode D1, and when the commercial AC power is cut off, power is supplied from the battery 4a to the load circuit 3 via the diode D3. . At this time, the backflow prevention diodes D1 to D3 supply backflow to both the AC-DC conversion device 2 and the power supply backup circuit 4 from one side to the other side so as to prevent backflow so as not to adversely affect the device. To prevent.

[0005]

The conventional power source backup device has a structure in which the battery 4a is almost always charged. When there is no abnormality in the commercial power source, the battery 4a is charged.
Is rarely discharged. Generally, the battery 4a is capable of exerting its original function (supplying power to the control circuit of the device in place of the commercial power supply for a certain period of time) when it is repeatedly charged and discharged. If you just charge the battery without discharging it, the backup time will become shorter and shorter due to the memory effect of the battery. In addition, it is not possible to know the current function of the battery 4a (how long the control circuit of the device can be backed up by the commercial power source while the device is operating). It is possible to discharge the battery 4a and check the remaining capacity at the same time as the maintenance of the device, but if a power outage occurs immediately after inspection, there is almost no backup available time because the charge is not satisfied. Because there is
It cannot be easily inspected.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to always grasp the state of the battery and activate it to extend the life, and always secure the function as the backup power source. The purpose of the invention is to obtain a power supply backup device.

[0007]

A power supply backup device according to the present invention comprises an AC-DC converter for converting a commercial AC power supply as an input into a constant voltage DC power supply and supplying the same to a load circuit, and the commercial AC power supply. In a power backup device including a power backup circuit that supplies backup power to the load when disconnected, the power backup circuit charges the first and second batteries and the first and second batteries. Battery charging circuit for
A battery voltage monitoring circuit for monitoring the terminal voltage of the first and second batteries, a charge switching circuit for switching charging for charging the first and second batteries by the battery charging circuit, and the battery voltage monitoring circuit A voltage monitoring switching circuit for performing monitoring switching for monitoring the terminal voltages of the first and second batteries, a battery discharging circuit for discharging the first and second batteries, and first and second
A load switching circuit for switching the load of each battery and a control circuit for sending a control signal to each of these components to control, and the control circuit switches the charging switching circuit to control the first and the second. The batteries are alternately charged, and when the commercial AC power source is normal, the load switching circuit is switched and controlled to discharge one of the first and second batteries to the battery discharging circuit, and the voltage is monitored. The charging / discharging characteristics of the first and second batteries are measured and recorded by switching control of the switching circuit.

Further, the control circuit controls the load switching circuit to alternately connect one of the first and second batteries to the load circuit and connect the other to a rest state. To do.

Further, the control circuit allows the first and second
It is characterized in that the battery is periodically charged and discharged for 2 weeks or once every several months.

Further, the above-mentioned control circuit is characterized in that the life of the battery is judged based on the measured and recorded charging / discharging characteristics and the necessity of replacement is output to the monitoring center.

[0011]

In the power supply backup device according to the present invention, the AC-DC converter for converting the commercial AC power supply into the constant voltage DC power supply and supplying it to the load circuit, and the commercial AC power supply when the commercial AC power supply is disconnected. In a power supply backup device including a power supply backup circuit that supplies backup power to the load, the power supply backup circuit includes:
First and second batteries, a battery charging circuit for charging the first and second batteries, first and second
A battery voltage monitoring circuit for monitoring the terminal voltage of the battery, a charge switching circuit for switching the charging for charging the first and second batteries by the battery charging circuit, and a first and a first battery voltage monitoring circuit for the battery voltage monitoring circuit. A voltage monitoring switching circuit that performs monitoring switching for monitoring the terminal voltage of the second battery, a battery discharging circuit that discharges the first and second batteries, and a load switching that switches the loads of the first and second batteries, respectively. A circuit and a control circuit for sending and controlling a control signal to each of these components,
The control circuit switches and controls the charging switching circuit to alternately charge the first and second batteries, and
When the commercial AC power supply is normal, the load switching circuit is controlled to be switched to discharge one of the first and second batteries to the battery discharging circuit, and the voltage monitoring switching circuit is controlled to switch to the first. By measuring and recording the charge and discharge characteristics of the first and second batteries, the state of the battery can always be grasped and activated to prolong the life of the battery, and the function as a backup power source is always ensured.

Further, the control circuit controls the load switching circuit to alternately connect one of the first and second batteries to the load circuit and put the other in a rest state to reduce the load on the battery. To extend the service life.

Further, by the control circuit, the first and second
By regularly charging and discharging the battery for 2 weeks or once every several months, it is possible to avoid the deterioration of the battery function in a short time and to secure the initial capacity of the battery for a long time. .

Furthermore, the control circuit determines the battery life based on the measured and recorded charging / discharging characteristics and outputs the necessity of replacement to the monitoring center, thereby making it possible to notify the battery replacement time. .

[0015]

【Example】

Example 1. Hereinafter, the present invention will be described based on illustrated embodiments. 1 is a block diagram showing a power supply backup device according to a first embodiment of the present invention. In FIG. 1, the same reference numerals as those in the conventional example shown in FIG. 6 indicate the same parts, 1 is an input plug of a commercial AC power supply, 2 is an AC-DC converter for converting the commercial AC power supply into a constant voltage DC power supply, and 3 is a reverse flow. The load circuit driven by the constant voltage DC power source from the AC-DC converter 2 via the prevention diode D1 is shown. Further, as a new reference numeral, reference numeral 5 is a power supply backup circuit according to the first embodiment that supplies power for driving the load circuit 3 when the commercial AC power supply is cut off, and has a configuration described later.

That is, the power source backup circuit 5 includes a first battery 5a and a second battery 5a.
b, a battery charging circuit 5c for charging the first and second batteries 5a and 5b, a battery voltage monitoring circuit 5d for monitoring the terminal voltage of the first and second batteries 5a and 5b, and one battery A charge switching circuit 5e that performs charge switching for charging the two batteries 5a and 5b with the charging circuit 5c, and a monitor for monitoring the terminal voltages of the two batteries 5a and 5b with the same battery voltage monitoring circuit 5d. A voltage monitoring switching circuit 5f for switching, a battery discharging circuit 5g for discharging the battery instead of the load circuit 3 for activating the battery, and a load switching for switching the loads of the first and second batteries 5a and 5b, respectively. Circuits 5h and 5i, and a control circuit 5 for sending and controlling control signals CNT1 to CNT7 to these components If, for backflow prevention diode D2~D
4 and.

Next, the operation of the above configuration will be described. FIG. 2 is a diagram for explaining an operating state based on the control of the control circuit 5j of the power source backup circuit 5. The control operation is roughly divided into two types, one is a state in which the power source is backed up, and the other is a backup function. It shows the state of testing. Hereinafter, description will be given with reference to FIG.
The state during the functional test of the battery includes the charge / discharge characteristic test (four types in total) of each of the first and second batteries 5a and 5b. The switching state of each switching circuit at this time is as shown in FIG.

That is, first, while the power supply is backed up, the control circuit 5j controls the switching of the charge switching circuit 5e to switch the batteries 5a and 5b at regular intervals, and similarly the switching control of the voltage monitoring switching circuit 5f. The batteries 5a and 5b are switched at regular intervals, and the load switching circuits 5h and 5i are switching-controlled to switch between the charging side and the normal side at regular intervals. At this time, the batteries backing up the power sources are the batteries 5a and 5b.

On the other hand, during the functional test of the battery, for example, when testing the charging characteristics of the first battery 5a, the control circuit 5j controls the switching of the charging switching circuit 5e to switch the batteries 5a and 5b at regular intervals. Similarly, the voltage monitoring switching circuit 5f is switching-controlled to switch the batteries 5a and 5b at regular intervals, the load switching circuit 5h is switching-controlled to be fixed to the charging side, and the load switching circuit 5i is switching-controlled. And fix it on the normal side. At this time, the battery backing up the power source is only the battery 5b.

When the discharge characteristic of the first battery 5a is tested, the charge switching circuit 5e is controlled by the control circuit 5j to be fixed on the second battery 5b side.
The voltage monitoring switching circuit 5f is switching-controlled to switch the batteries 5a and 5b at regular intervals, and the load switching circuit 5h is switching-controlled to be fixed to the discharging side, and the load switching circuit 5i is switching-controlled to be the normal side. Fixed to. At this time, the battery backing up the power source is only the battery 5b.

When testing the charging characteristics of the second battery 5b, the control circuit 5j controls the switching of the charging switching circuit 5e to switch the first and second batteries 5a and 5b at regular intervals. In addition, the voltage monitoring switching circuit 5f is switching-controlled to control the battery 5 at regular intervals.
a and 5b are switched, and the load switching circuit 5h
Is controlled to be fixed to the normal side, and the load switching circuit 5i is controlled to be fixed to the charging side. At this time, the battery backing up the power source is only the battery 5a.

Further, at the time of testing the discharge characteristic of the second battery 5b, the control circuit 5j performs switching control of the charge switching circuit 5e to fix it on the first battery 5a side, and switching control of the voltage monitoring switching circuit 5f. Then, the batteries 5a and 5b are switched at regular intervals, and the load switching circuit 5h is switching-controlled to be fixed to the normal side, and the load switching circuit 5i is switching-controlled to be fixed to the discharging side. At this time, the battery backing up the power source is only the battery 5a.

Here, the control circuit 5j conducts a functional test of the battery as described above and measures the temporal change of the battery terminal voltage based on the output of the battery voltage monitoring circuit 5d to charge and discharge the battery. By repeating, the function of the battery is maintained for a long time in a state close to the initial state (when new).

That is, the first and second batteries 5a
As 5 and 5b, for example, a rechargeable nickel-cadmium battery is used. Generally, the charge / discharge characteristics of the rechargeable nickel-cadmium battery are as shown in FIGS. 3 and 4, and the time variation of the battery terminal voltage is measured. If you do so, you can grasp the current function. When charging is always performed and discharging is not performed, the initial state can be maintained by moving the charging / discharging characteristics in the deterioration direction and repeating charging / discharging correctly.

Next, FIG. 5 shows how the control circuit 5j connects the battery to the load circuit 3. The batteries 5a and 5b are either one of the batteries except for parallel connection when the batteries are switched. This is because while one of the batteries is in operation, the other is disconnected from the circuit and put into a rest state.
Putting the battery in a rest state reduces the burden on the battery and extends its life. The functional test of the battery is performed while one is in operation, and the time until the terminal voltage of the battery for both discharge and charge reaches the specified value is measured and recorded. Further, the discharge / charge characteristic test is performed at intervals of 2 weeks to several months. This is because charging and discharging in a short period of time becomes a factor that deteriorates the function of the battery. Further, the result of the charge / discharge characteristic test is recorded in the control circuit 5j. For example, when the initial state is lowered three times in a row (about 70% or less), it is determined that the battery has reached the end of life. Notify the monitoring center of the next replacement requirement.

Therefore, according to the above embodiment, it is possible to back up the power supply of the target device while maintaining the function of the battery close to the initial state (when it is new) for a long time. Also, it is possible to know the proper battery replacement time.

[0027]

As described above, according to the present invention, an AC-DC converter for converting a constant-voltage direct-current power supply using a commercial alternating-current power supply as an input and supplying it to a load circuit, and the commercial alternating-current power supply are disconnected. In a power supply backup device including a power supply backup circuit that supplies backup power to the load, the power supply backup circuit is provided for charging the first and second batteries and the first and second batteries. A battery charging circuit and a battery voltage monitoring circuit for monitoring the terminal voltage of the first and second batteries,
A charge switching circuit for switching charging for charging the first and second batteries in the battery charging circuit, and a monitoring switching for monitoring terminal voltages of the first and second batteries in the battery voltage monitoring circuit. A voltage monitoring switching circuit for performing, a battery discharging circuit for discharging the first and second batteries, a load switching circuit for switching the loads of the first and second batteries, and a control signal sent to each of these components for control. And a charging control circuit for switching the charging switching circuit to alternately charge the first and second batteries, and switching the load switching circuit when the commercial AC power supply is normal. Control to discharge one of the first and second batteries to the battery discharge circuit, and to switch the voltage monitoring switching circuit to control the And by the charge and discharge characteristics of the second battery is measured and recorded, and keeps track of the state of the battery can extend the life activated, can always secure a function as a backup power source.

Further, the control circuit controls the load switching circuit to alternately connect one of the first and second batteries to the load circuit and put the other in a rest state to reduce the load on the battery. The life can be extended.

Further, the above-mentioned control circuit allows the first and second
By periodically charging and discharging the battery for 2 weeks or once every several months, it is possible to avoid the deterioration of the battery function in a short time and to secure the initial capacity of the battery for a long time.

Further, by the control circuit, the battery life is judged based on the measured and recorded charging / discharging characteristics, and the necessity of replacement is output to the monitoring center, so that the battery replacement time can be notified.

[Brief description of drawings]

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

FIG. 2 is a control circuit 5 of the power supply backup circuit 5 of FIG.
It is explanatory drawing about the operating state based on the control of j.

FIG. 3 is a charging characteristic diagram of a general battery (nickel cadmium battery).

FIG. 4 is a discharge characteristic diagram of a general battery (nickel cadmium battery).

5 is an explanatory diagram of a connection state of the battery of FIG.

FIG. 6 is a configuration diagram showing a conventional power supply backup device.

[Explanation of symbols]

2 AC-DC converter, 3 load circuit, 5 power supply backup circuit, 5a first battery, 5b second battery-, 5c battery charging circuit, 5d battery monitoring circuit, 5e charging switching circuit, 5f voltage monitoring switching circuit, 5g battery discharge circuit, 5h, 5i load switching circuit, 5j control circuit.

Claims (4)

[Claims] 1. An AC-DC converter for converting a commercial AC power supply into a constant-voltage DC power supply and supplying it to a load circuit, and a backup power supply for the load when the commercial AC power supply is cut off. In a power backup device including a power backup circuit, the power backup circuit includes a first and a second battery, and a first and a second battery.
Battery charging circuit for charging the first battery, a battery voltage monitoring circuit for monitoring the terminal voltage of the first and second batteries, and a charge switching for charging the first and second batteries with the battery charging circuit A charge switching circuit for performing the above, a voltage monitoring switching circuit for performing monitoring switching for monitoring the terminal voltages of the first and second batteries with the battery voltage monitoring circuit, and a battery discharging for discharging the first and second batteries A circuit, a load switching circuit for switching between the loads of the first and second batteries, and a control circuit for sending a control signal to each of these components to control, and the control circuit controls switching of the charging switching circuit. Then, the first and second batteries are alternately charged, and the load switching circuit is switched and controlled when the commercial AC power supply is normal. Discharging one of the first and second batteries to the battery discharging circuit, and switching control of the voltage monitoring switching circuit to measure and record the charging / discharging characteristics of the first and second batteries. And power backup device. 2. The control circuit controls the load switching circuit to alternately connect one of the first and second batteries to the load circuit and connect the other to a rest state. The power backup device according to claim 1. 3. The power supply backup according to claim 1, wherein the control circuit periodically charges and discharges the first and second batteries once every two weeks to several months. apparatus. 4. The control circuit according to claim 1, wherein the control circuit determines the life of the battery based on the measured and recorded charging / discharging characteristics and outputs the necessity of replacement to the monitoring center. The power supply backup device described.