JP2000287354A - Voltage regulating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a voltage regulating apparatus which performs a protective operation properly under various conditions and whose reliability is enhanced. SOLUTION: A control circuit part 8 which controls a power circuit part 6 on the basis of an output voltage, which executes a protection changeover operation by a protective circuit part 7 when the output voltage is lowered to a prescribed protection condition value, and which executes an automatic return operation used to release the protection changeover operation by the protective circuit part when the output voltage is raised to the prescribed return condition value, is provided. The control circuit part 8 inhibits a next automatic return operation when the automatic return operation reaches the prescribed number of times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage regulator connected between a main power supply line and a showcase serving as a load in a store such as a convenience store.

[0002]

2. Description of the Related Art Conventionally, in a convenience store or the like of this type, a power regulator is installed at a stage subsequent to a main breaker of a power supply line, and the voltage of the main power supply line is reduced to adjust the power consumption of load equipment such as a showcase. To reduce electricity costs.

[0003] In addition, this type of voltage regulator is used when the voltage regulator itself fails, or when an abnormal situation such as an overload or a drop in the power supply voltage occurs and the output voltage drops abnormally, the load device becomes inoperable. In order to allow the voltage regulator to operate normally, a protection switch function is provided that directly connects the input and output of the voltage regulator with a magnet switch or the like and excludes the voltage regulator itself from the power supply line.

When the output voltage rises to a predetermined recovery condition, the protection switching is released and the voltage adjustment function is automatically recovered. Thus, even when the protection switching function is activated due to a temporary and one-time voltage drop such as at the time of starting the load device, the protection switching function is intended to be quickly restored to exhibit the energy saving effect.

[0005]

However, in such a conventional configuration, when the power supply line has a continuous voltage drop cycle, the protection switching function and the return function are repeated, so that the magnet switch or the like is not used. There has been a problem that the cost of parts rises, for example, the set life is remarkably shortened, or the capacity is required to be increased.

[0006] Also, in a region where power supply conditions are poor, the power supply voltage may not be reduced to an unusual level, but a low voltage state unfavorable for load equipment may continuously occur. Since the protection switching function does not work, there is a problem that the load device cannot operate normally due to the voltage drop in the wiring.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional technical problems, and an object of the present invention is to provide a voltage regulator capable of performing appropriate protection under various conditions and improving reliability. Aim.

[0008]

That is, a voltage regulator according to the first aspect of the present invention is connected between a main power supply line and a load device and adjusts an output voltage to a set value. A power circuit unit that performs a protection switching operation that excludes the power circuit unit from the power supply line;
Controlling the power circuit unit based on the output voltage, and executing the protection switching operation by the protection circuit unit when the output voltage drops to a predetermined protection condition value, and when the output voltage rises to a predetermined return condition value And a control circuit unit for executing an automatic return operation for canceling the protection switching operation by the protection circuit unit. The control circuit unit inhibits the next automatic return operation when the automatic return operation reaches a predetermined number of times. It is characterized by the following.

According to the first aspect of the present invention, in a voltage regulator connected between a main power supply line and a load device for adjusting an output voltage to a set value, a power circuit unit for adjusting an output voltage, and the power circuit unit A protection circuit for executing a protection switching operation for removing the power supply line from the power supply line, and controlling the power circuit based on the output voltage, and performing protection switching by the protection circuit when the output voltage decreases to a predetermined protection condition value. And a control circuit for executing an automatic return operation for canceling the protection switching operation by the protection circuit when the output voltage rises to a predetermined return condition value. On the other hand, the protection switching operation is automatically performed, and the normal operation of the load device can be ensured.
In addition, for temporary and single voltage drops such as when starting load equipment, energy can be saved by automatic recovery after protection switching.
Electricity bill reduction effects can also be ensured.

[0010] In particular, the control circuit inhibits the next automatic return when the automatic return operation reaches a predetermined number of times. Therefore, the control circuit suppresses the number of times of operation of the protection circuit against repeated voltage abnormal drops. The service life can be extended.

Further, the voltage adjusting device of the invention according to claim 2 is
A power circuit connected between the main power supply line and the load device for adjusting an output voltage to a set value, and performing a protection switching operation for excluding the power circuit from the power supply line for adjusting the output voltage. Controlling the protection circuit unit and the power circuit unit based on the output voltage, and executing the protection switching operation by the protection circuit unit when the output voltage decreases to a predetermined protection condition value, and setting the output voltage to a predetermined return condition. And a control circuit unit for executing an automatic return operation for canceling the protection switching operation by the protection circuit unit when the output voltage has risen to a value, the control circuit unit having an output voltage lower than the set value and lower than the protection condition value. When the high state is continued for a predetermined period, the protection switching operation is performed by the protection circuit unit, and the automatic return is prohibited.

According to the second aspect of the present invention, in a voltage adjusting device connected between a main power supply line and a load device for adjusting an output voltage to a set value, a power circuit unit for adjusting an output voltage, and the power circuit unit A protection circuit for executing a protection switching operation for removing the power supply line from the power supply line, and controlling the power circuit based on the output voltage, and performing protection switching by the protection circuit when the output voltage decreases to a predetermined protection condition value. And a control circuit for executing an automatic return operation for canceling the protection switching operation by the protection circuit when the output voltage rises to a predetermined return condition value. The protection switching operation is automatically performed in response to the decrease, and the normal operation of the load device can be ensured. In addition, with respect to a temporary and single voltage drop such as at the time of starting the load device, it is possible to secure energy saving and electricity cost reduction effects by automatic recovery after protection switching.

In particular, when the output voltage is lower than the set value and higher than the protection condition value for a predetermined period, the control circuit causes the protection circuit to execute the protection switching operation and inhibits automatic recovery. Therefore, for example, the protection switching operation is performed even in a continuous voltage drop state caused by the supplied power supply voltage, and the normal operation of the load device can be maintained.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a voltage regulator 1 of the present invention, and FIG. 2 is a detailed configuration diagram thereof. The voltage regulator 1 according to the present invention includes a main breaker 2 connected to a rear stage of a power supply AC in a store such as a convenience store.
And a load device 3 composed of a showcase, a branch breaker, and the like, which is connected to the load device 3 and adjusts an output voltage supplied to the load device 3 to a set value to reduce power consumption and reduce electricity cost. The power circuit 6 includes a power circuit 6, a protection circuit 7, a control circuit 8, an input terminal 9 connected to the main breaker 2, an output terminal 11 connected to the load device 3, and the like. .

The power supply AC of the embodiment is a single-phase three-wire AC 100 V (or 200 V) power supply. The power circuit section 6 and the protection circuit section 7 of the voltage regulator 1 are used for the R phase of the power supply AC. Each is provided for the T phase. As shown in FIG. 2, the power circuit unit 6 includes a main transformer 16 connected to a power supply line, a mag-amp (saturable reactor) 17 for voltage adjustment, and a choke coil 18. The mag-amp 17 is a control circuit unit. 8 voltage control outputs (terminals) 8
A is connected. Although FIG. 2 shows only the R phase, the same applies to the T phase.

Each of the protection circuit portions 7 includes a normally open contact 21 and a normally closed contact 22 each formed of a magnet switch. The normally open contact 21 is connected between the input terminal 9 and the output terminal 11 so that when the circuit is closed, The power circuit 6 is short-circuited. The normally closed contact 22 is connected between the main transformer 16 and the neutral point, and disconnects the main transformer 16 from the power supply line when the circuit is opened. Terminal 8B). When the protection switching output 8B of the control circuit 8 is turned on, the normally open contact 21 is closed and the normally closed contact 22 is opened.

Further, the control circuit section 8 includes an electronic circuit and operation switches for the controller, a setting volume for setting a set value of the output voltage, a display lamp and a buzzer, and the like. An input voltage Vi serving as a power source of the control circuit unit 8 is input from a stage subsequent to the terminal 9, and an output voltage Vo for detection is input from a stage preceding the output terminal 11.
(Value) is entered.

In the above configuration, the control circuit 8 outputs the output voltage V
o and the set value V of the output voltage set by the setting volume
s (for example, 100 V), and sends a control output from the voltage adjustment output 8A to the mag amplifier 17 to adjust the output voltage Vo to the set value Vs. Accordingly, in a state where the voltage of the power supply AC is higher than the set value, the voltage of the main power supply line is reduced to the set value Vs, and the reduced output voltage Vo is supplied to the load device 3, so that the consumption of the load device 3 Power can be reduced.

Next, a protection operation by the control circuit unit 8 of the voltage regulator 1 will be described with reference to FIGS. For example, when the output voltage Vo decreases due to an overload, the control circuit unit 8 first sends a control output from the voltage adjustment output 8A to the mag amplifier 17 so as to increase the output voltage Vo. Then, the output voltage Vo still decreases, for example, 90
When the voltage drops to the protection condition value V11 which is an abnormally low voltage such as V, the control circuit unit 8 proceeds to step S3 after step S1 and step S2 in FIG. 3 and executes protection switching processing.

In step S3, the control circuit 8 turns on the protection switching output 8B to close the normally open contact 21 of the protection circuit 7 as described above, and the input terminal 9 and the output terminal 1
1 and the normally closed contact 22 is opened to disconnect the power circuit 6 from the power line (FIG. 4). Also, the fact that the protection switching operation has been started is notified to the outside by the lamp or the buzzer. As a result, the adjusting function of the power adjusting device 1 is deleted, and the power supply AC is applied to the load device 3 as it is. Then, in step S4, the control circuit unit 8 resets, for example, a 15-minute (T1) automatic return delay timer provided as its function.

Thereafter, in step S1, the control circuit unit 8 determines whether or not the abnormal voltage drop protection switching is currently being performed. Since the switching is being performed, the process proceeds to step S5. In step S5, it is determined whether an automatic return voltage condition is satisfied. This judgment is based on the output voltage V
This is a determination of whether or not o has only increased to a return condition value Vr such as, for example, 95 V. If the output voltage Vo has recovered to the return condition value Vr, the control circuit unit 8 proceeds from step S5 to step S6.

In step S6, it is determined whether an automatic return time condition is satisfied. This judgment is for judging whether or not the output voltage Vo has risen to the return condition value Vr as described above and the state has been continued for 15 minutes (T1) counted by the automatic return delay timer. Voltage V
When o has recovered to such a state, the control circuit unit 8 proceeds from step S6 to step S7.

In step S7, it is determined whether or not the number of times of automatic return is within the limit. In this case, the limit value of the number of times of automatic restoration is set to two times, which is the first time in this case, so that the control circuit unit 8 proceeds from step S7 to step S8 and turns off the protection switching output 8B. As a result, the normally open contact 21 of the protection circuit unit 7 is opened and the normally closed contact 22 is closed, so that the protection switching operation is released and the voltage adjustment function is restored. Also,
The operation of the lamp and the buzzer also stops.

However, the protection switching operation due to the abnormal voltage drop is performed twice, and the automatic recovery is performed each time.
After the number of times of the automatic recovery becomes two, if the voltage abnormal drop occurs again and the protection switching operation is executed, the output voltage V
Even if o returns and proceeds to steps S5 to S7,
Since this is the third time, the control circuit unit 8 determines in step S8
And automatic return is prohibited.

Thus, it is possible to suppress the number of operations of the contacts 21 and 22 of the protection circuit section 7 against repeated voltage abnormal drops, and to extend the life of the contacts. The prohibition state can be manually released by a switch of the control circuit unit 8 and restored.

Next, in an area where power supply conditions are particularly bad, as shown in FIG. 6, the output voltage Vo drops abnormally (V11).
Although it cannot be said that it is lower than the set value Vs, for example, Vl
When the voltage drops to between 2 (94 V) and V13 (91 V), the control circuit unit 8 proceeds from step S11 to step S12 in FIG. 5, and determines whether the voltage drop duration time condition is satisfied. This determination is a determination as to whether or not the voltage reduction state has continued for, for example, three hours (T2) counted by a voltage reduction duration timer included in the control circuit unit 8 as its function. Is the step S13
And the same protection switching process as described above is executed. And
Thereafter, automatic return is prohibited.

As a result, the protection switching operation can be performed even in a continuous voltage drop state caused by the supplied voltage of the power supply AC, and the normal operation of the load device 3 can be maintained. Note that the prohibition state in this case can also be manually released and restored by a switch of the control circuit unit 8.

[0028]

As described above, according to the first aspect of the present invention,
In a voltage regulator connected between a main power supply line and a load device for adjusting an output voltage to a set value, a power circuit unit for adjusting an output voltage and a protection switching operation for excluding the power circuit unit from the power line are executed. Controlling the protection circuit unit and the power circuit unit based on the output voltage, and executing the protection switching operation by the protection circuit unit when the output voltage decreases to a predetermined protection condition value, and setting the output voltage to a predetermined return condition. A control circuit unit for executing an automatic return operation for canceling the protection switching operation by the protection circuit unit when the voltage has risen to a value. Normal operation of the load device can be ensured. In addition, temporary operation such as when starting load equipment
With respect to a single voltage drop, energy saving and reduction of electricity costs can be ensured by automatic recovery after protection switching.

In particular, when the automatic return operation reaches a predetermined number of times, the control circuit unit inhibits the next automatic return operation. Therefore, the control circuit unit suppresses the number of times of operation of the protection circuit unit against repeated voltage abnormal drops. The service life can be extended.

According to the second aspect of the present invention, there is provided a voltage adjusting device connected between a main power supply line and a load device for adjusting an output voltage to a set value. A protection circuit unit for performing a protection switching operation for excluding the circuit unit from the power supply line, and controlling the power circuit unit based on the output voltage, and when the output voltage decreases to a predetermined protection condition value, the protection circuit unit A control circuit unit for executing a protection switching operation and performing an automatic return operation for canceling the protection switching operation by the protection circuit unit when the output voltage rises to a predetermined return condition value. The protection switching operation is automatically executed in response to the abnormal voltage drop, so that the normal operation of the load device can be ensured. In addition, temporary operation such as when starting load equipment
With respect to a single voltage drop, energy saving and reduction of electricity costs can be ensured by automatic recovery after protection switching.

In particular, when the state in which the output voltage is lower than the set value and higher than the protection condition value is continued for a predetermined period, the control circuit unit executes the protection switching operation by the protection circuit unit and inhibits automatic return. Therefore, for example, the protection switching operation is performed even in a continuous voltage drop state caused by the supplied power supply voltage, and the normal operation of the load device can be maintained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a voltage regulator according to the present invention.

FIG. 2 is a detailed configuration diagram of a voltage regulator according to the present invention.

FIG. 3 is a flowchart illustrating a protection operation of a control circuit unit of the voltage adjustment device according to the present invention.

FIG. 4 is a timing chart illustrating states of an input voltage, an output voltage, and a protection switching output of a control circuit unit for explaining the protection operation of FIG. 3;

FIG. 5 is a flowchart illustrating another protection operation of the control circuit unit of the voltage regulator according to the present invention.

6 is a timing chart showing states of an input voltage, an output voltage, and a protection switching output of a control circuit unit for explaining the protection operation of FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 voltage regulator 2 main breaker 6 power circuit section 7 protection switching section 8 control circuit section

Claims (2)

[Claims] 1. A voltage adjusting device connected between a main power supply line and a load device for adjusting an output voltage to a set value, wherein a power circuit unit for adjusting the output voltage and the power circuit unit are excluded from the power line. A protection circuit unit that performs a protection switching operation, and controls the power circuit unit based on the output voltage, and executes the protection switching operation by the protection circuit unit when the output voltage decreases to a predetermined protection condition value. When the output voltage rises to the predetermined return condition value,
A control circuit unit for executing an automatic return operation for canceling the protection switching operation by the protection circuit unit, wherein the control circuit unit inhibits the next automatic return when the automatic return operation reaches a predetermined number of times. A voltage regulator characterized by the above-mentioned. 2. A voltage regulator connected between a main power supply line and a load device for adjusting an output voltage to a set value, wherein the power circuit adjusts the output voltage, and the power circuit is excluded from the power supply line. A protection circuit unit that performs a protection switching operation, and controls the power circuit unit based on the output voltage, and executes the protection switching operation by the protection circuit unit when the output voltage decreases to a predetermined protection condition value. When the output voltage rises to the predetermined return condition value,
A control circuit unit for executing an automatic return operation for canceling the protection switching operation by the protection circuit unit, wherein the control circuit unit is configured so that a state in which the output voltage is lower than a set value and higher than the protection condition value is maintained for a predetermined period. A voltage adjustment device, wherein, when continued, a protection switching operation is performed by the protection circuit unit and automatic recovery is prohibited.