JP2003299362A - Voltage regulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voltage regulator which can suitably protect a load device even in a state that an input voltage from a power line is normally lower. <P>SOLUTION: A control circuit 8 controls a power circuit 6 based on an output voltage. When the output voltage is lowered from a lower limit value of a supplied specified voltage to the load device 3 and this state is continued for a predetermined period, the protective switching operation of a protective circuit 7 is performed. The circuit 8 has a predetermined warning means to inhibit the operation of the warning means in association with the protective switching operation. The circuit 8 performs an automatic resetting operation for eliminating the protective switching operation by the circuit 7, when the output voltage is raised to a predetermined resetting condition value after a predetermined standby period is elapsed after the protective switching operation is started, and this state is continued for a predetermined period. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, in a convenience store of this type, a voltage regulator is installed after the main breaker of the power supply line to reduce the voltage of the main power supply line to reduce the power consumption of load equipment such as a showcase. To reduce electricity costs.

Conventionally, this type of voltage regulator has an output voltage of 90 V when the voltage regulator itself fails or when a voltage drop occurs when a device inside or around the store is activated. When the voltage drops below the level, a protection switch function is provided to directly connect the input and output of the voltage regulator with a magnet switch or the like to operate the load device normally and to exclude the voltage regulator itself from the power supply line.

[0004]

Here, the input voltage (power receiving voltage of a store) supplied from an electric power company is 10 by definition.
Since it is set to 1V ± 6V, the lower limit value of the specified voltage supplied to the load is 95V. On the other hand, in this type of voltage regulator, a saturable reactor is used as a power circuit unit for adjusting the output voltage, but due to its circuit characteristics,
The minimum voltage drop in the power circuit section is a relatively large value, for example, about 2V.

Therefore, if the input voltage (received voltage) from the main power supply line is lowered to 97 V or less under a constantly low condition, the output voltage is 95 V or less, which is the lower limit value of the specified voltage at the maximum. However, some devices have defects depending on their characteristics and usage environment.
However, such a situation cannot be dealt with by the protection switching function of the conventional voltage regulator, and therefore, the voltage regulator is often installed only in a store with a high input voltage.

The present invention has been made in order to solve the above-mentioned conventional technical problems, and a voltage adjusting device capable of appropriately protecting a load device even under a situation where an input voltage from a power supply line is always low. The purpose is to provide.

[0007]

That is, a voltage adjusting device of the present invention is connected between a main power supply line and a load device to adjust an output voltage to a set value, and a power circuit for adjusting the output voltage. Section, a protection circuit section that executes a protection switching operation that excludes this power circuit section from the power supply line, the power circuit section that controls the power circuit section based on the output voltage, and the output voltage is the lower limit of the specified voltage supplied to the load device. And a control circuit section that executes a protection switching operation by the protection circuit section when the value is lower than a value and the state continues for a predetermined period.

According to the present invention, in a voltage adjusting device which is connected between a main power supply line and a load device and adjusts an output voltage to a set value, a power circuit section for adjusting the output voltage, and a power line section for connecting the power circuit section The protection circuit unit that executes the protection switching operation that is excluded from the control circuit and the power circuit unit that controls the power circuit unit based on the output voltage, and the output voltage is lower than the lower limit value of the specified voltage supplied to the load device, and the state is Since it has a control circuit section that executes a protection switching operation by the protection circuit section when it continues for a predetermined period of time, in a situation where the input voltage from the main power supply line is always lower than the lower limit value of the specified voltage, It becomes possible to automatically execute the protection switching operation and eliminate the decrease in the output voltage due to the voltage drop in the power circuit section.

As a result, it becomes possible to secure an output voltage that is equal to or higher than the lower limit value of the specified voltage, and it is possible to prevent the occurrence of problems caused by the fact that a voltage lower than the lower limit value is continuously supplied to the load device. The normal operation can be ensured.

According to a second aspect of the voltage regulator of the present invention, the control circuit section is provided with a predetermined alarm means, and the operation of the alarm means accompanying the execution of the protection switching operation is prohibited.

According to the second aspect of the present invention, in addition to the above, the control circuit section is provided with a predetermined alarm means, but since the operation of the alarm means accompanying the execution of the protection switching operation is prohibited, the input voltage is originally low. In the use situation, it is possible to avoid the inconvenience of frequent alarms even though the voltage regulator is normal.

In the voltage regulator of the invention of claim 3, in each of the above inventions, the control circuit section causes the output voltage to rise to a predetermined reset condition value after a lapse of a predetermined waiting period after the start of the protection switching operation. Further, when the state continues for a predetermined period, an automatic return operation for canceling the protection switching operation by the protection circuit unit is executed.

According to the third aspect of the present invention, in addition to the above respective aspects, the control circuit section increases the output voltage to a predetermined return condition value after a predetermined waiting period has elapsed after the start of the protection switching operation. In addition, when the state continues for a predetermined period of time, the protection switching operation by the protection circuit section is automatically reset, so if the input voltage is restored to normal, it automatically recovers after the protection switching. It will also be possible to secure energy saving and electricity cost reduction effects.

In particular, when the output voltage rises to a predetermined reset condition value after a lapse of a predetermined standby period after the start of the protection switching operation, and the state continues for a predetermined period, the protection circuit section protects. Since the switching operation is canceled, the number of operations of the protection circuit section can be suppressed and the life of the protection circuit section can be extended.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a voltage adjusting device 1 of the present invention, and FIG. 2 is a detailed configuration diagram thereof. The voltage adjustment device 1 of the present invention is a main circuit breaker 2 connected to a subsequent stage of a power supply AC in a store such as a convenience store.
And a load device 3 including a power distribution breaker 10 and a showcase, are connected by wiring, and the output voltage supplied to the load device 3 is adjusted to a set value to reduce the power consumption,
It is used to reduce the cost of electricity,
It is composed of a power circuit section 6, a protection circuit section 7, a control circuit section 8, an input terminal 9 connected to the main breaker 2, an output terminal 11 connected to the load device 3 via a distribution breaker 10, and the like.

The power supply AC of the embodiment is a single-phase three-wire type AC 100V power supply, and the specified supply voltage to the load device 3 is 1.
It is 01V ± 6V. The power circuit section 6 and the protection circuit section 7 of the voltage regulator 1 are provided for the R phase and the T phase of the power source AC, respectively. As shown in FIG. 2, the power circuit unit 6 includes a main transformer 16 connected to a power supply line.
And mag-amp (saturable reactor) for voltage adjustment 17
And the choke coil 18, the mag-amp 1
7 is connected to the voltage control output (terminal) 8A of the control circuit unit 8. Although FIG. 2 shows only the R phase, the same applies to the T phase.

Further, the protection circuit section 7 is composed of a normally open contact 21 and a normally closed contact 22 both of which are magnetic switches. The normally open contact 21 is connected between the input terminal 9 and the output terminal 11, and when the circuit is closed, The power circuit unit 6 is short-circuited. Further, the normally-closed contact 22 is connected between the main transformer 16 and the neutral point to disconnect the main transformer 16 from the power supply line when the circuit is opened. Each contact 21, 22 is a protection switching output of the control circuit unit 8 ( Terminal) 8B. When the protection switching output 8B of the control circuit unit 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 is provided with an electronic circuit for the controller, an operation switch, a setting volume 8C for setting the set value of the output voltage, and an alarm means such as a display lamp and a buzzer. Input terminal 9 on 8
The input voltage Vi which becomes the power source of the control circuit unit 8 itself from the latter stage
And the output voltage Vo (value) for detection is input from the preceding stage of the output terminal 11.

With the above configuration, the control circuit section 8 outputs the output voltage V
o is compared with a set value (for example, 95 V) of the output voltage set by the setting volume 8C, and a control output is sent from the voltage adjustment output 8A to the mag amp 17 to adjust the output voltage Vo to the set value. As a result, when 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, and the reduced output voltage Vo is applied to the load device 3.
Is supplied to the load device 3, the power consumption of the load device 3 can be reduced.

Next, the protection operation by the control circuit unit 8 of the voltage regulator 1 will be described with reference to FIG. For example, when the input voltage Vi from the main power line is always low and the input voltage Vi further decreases, the power circuit unit 6
The output voltage Vo also decreases with a difference as small as the voltage drop (for example, 2 V) at. The output voltage Vo is the lower limit value Vl of the specified voltage supplied to the load device 3 9
When the voltage becomes lower than 5 V and decreases to a predetermined protection switching condition voltage Vs (for example, 94 V) lower than the lower limit value V1 and the state continues for, for example, 15 minutes, the control circuit unit 8 executes the protection switching process.

In this protection switching process, the control circuit unit 8 turns on the protection switching output 8B to close the normally open contact 21 of the protection circuit unit 7 as described above, thereby inputting the input terminal 9 and the output terminal 1.
1 is directly connected and the normally closed contact 22 is opened to disconnect the power circuit unit 6 from the power supply line. As a result, the adjustment function of the power adjustment device 1 is deleted, and the power supply AC is directly applied to the load device 3, so that the input voltage Vi = the output voltage Vo = 96V and the load device 3 is regulated. A voltage equal to or higher than the lower limit value of the voltage will be supplied.

In this case, the control circuit section 8 does not issue the alarm by the lamp or the buzzer. As a result, it is not necessary to frequently warn the decrease of the input voltage Vi when the voltage regulator 1 is normal. However, the control circuit unit 8 issues a warning by a lamp or a buzzer when a protective operation occurs at the time of a voltage drop such as an overload or a failure occurs in the voltage adjusting device 1 itself.

Thereafter, the control circuit section 8 continues this protection switching process and maintains the state in which the input terminal 9 and the output terminal 11 are directly connected. After that (after the start of the protection switching process), for example, after a lapse of a waiting period of 24 hours, the output voltage Vo (= the input voltage Vi) rises to reach a predetermined recovery condition value Vr of 98 V or more, and When the state continues for 15 minutes, the control circuit unit 8 turns off the protection switching output 8B.

As a result, the normally open contact 21 of the protection circuit section 7
Is opened and the normally closed contact 22 is closed, the protection switching operation is released and the voltage adjusting function is restored.

As described above, the control circuit section 8 controls the power circuit section 6 based on the output voltage, and the output voltage is lower than the lower limit value of the regulated voltage supplied to the load device 3, and the state is The protection switching operation is performed by the protection circuit unit 7 when it continues for a predetermined period (15 minutes), so that automatically under the situation where the input voltage from the main power supply line is always lower than the lower limit value of the specified voltage. By performing the protection switching operation, it becomes possible to eliminate the decrease in the output voltage due to the voltage drop in the power circuit section 6.

As a result, it becomes possible to secure an output voltage that is equal to or higher than the lower limit value of the specified voltage, and it is possible to prevent the occurrence of problems caused by the fact that a voltage lower than the lower limit value is continuously supplied to the load device 3. Therefore, normal operation can be secured.

Further, the control circuit unit 8 has the output voltage increased to a predetermined return condition value after a predetermined waiting period (24 hours) has elapsed after the start of the protection switching operation, and the state is kept for a predetermined period. (15 minutes) If continued, the automatic switching operation for canceling the protection switching operation by the protection circuit unit 7 is executed.
When the input voltage returns to normal, it will be possible to automatically restore after protection switching to ensure the original energy saving and electricity cost reduction effects.

In particular, after a predetermined waiting period (24 hours) has elapsed after the start of the protection switching operation, the output voltage rises to a predetermined return condition value and the state is for a predetermined period (15 minutes).
When it continues, the protection switching operation by the protection circuit unit 7 is released, so that it is possible to suppress the number of operations of the contacts 21 and 22 of the protection circuit unit 7 and extend the life thereof.

[0029]

As described above in detail, according to the present invention, in the voltage adjusting device for adjusting the output voltage to the set value, which is connected between the main power supply line and the load device, the power circuit unit for adjusting the output voltage, A protection circuit section that executes a protection switching operation that excludes this power circuit section from the power supply line, and controls the power circuit section based on the output voltage, and the output voltage drops below the lower limit value of the specified voltage to be supplied to the load device. In addition, since the control circuit section that executes the protection switching operation by the protection circuit section when the state continues for a predetermined period is provided, the input voltage from the main power supply line is always lower than the lower limit value of the specified voltage. Under such circumstances, it becomes possible to automatically execute the protection switching operation and eliminate the decrease in the output voltage due to the voltage drop in the power circuit section.

As a result, it becomes possible to secure an output voltage that is equal to or higher than the lower limit value of the specified voltage, and it is possible to prevent the occurrence of problems caused by the fact that a voltage lower than the lower limit value is continuously supplied to the load equipment. The normal operation can be ensured.

According to the second aspect of the present invention, in addition to the above, the control circuit portion is provided with a predetermined alarm means, but since the operation of the alarm means accompanying the execution of the protection switching operation is prohibited, the input voltage is originally low. In the use situation, it is possible to avoid the inconvenience of frequent alarms even though the voltage regulator is normal.

According to the invention of claim 3, in addition to each of the above inventions, the control circuit section causes the output voltage to rise to a predetermined reset condition value after a predetermined standby period has elapsed after the start of the protection switching operation. In addition, when the state continues for a predetermined period of time, the protection switching operation by the protection circuit section is automatically reset, so if the input voltage is restored to normal, it automatically recovers after the protection switching. It will also be possible to secure energy saving and electricity cost reduction effects.

In particular, when the output voltage rises to a predetermined reset condition value after a lapse of a predetermined standby period after the start of the protection switching operation, and the state continues for a predetermined period, the protection circuit section protects the output voltage. Since the switching operation is canceled, the number of operations of the protection circuit section can be suppressed and the life of the protection circuit section can be extended.

[Brief description of 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 the voltage regulator of the present invention.

FIG. 3 is a timing chart showing the states of the input voltage, the output voltage, and the protection switching output of the control circuit unit for explaining the protection operation of the control circuit unit of the voltage regulator of the present invention.

[Explanation of symbols]

1 Voltage regulator 2 Master breaker 6 Power circuit section 7 Protection switching section 8 Control circuit section

Claims (3)

[Claims] 1. A voltage adjusting device, which is connected between a main power supply line and a load device and adjusts an output voltage to a set value, wherein a power circuit unit for adjusting the output voltage and the power circuit unit is excluded from the power supply line. A protection circuit unit that performs a protection switching operation, and the power circuit unit that controls the power circuit unit based on the output voltage, and the output voltage is lower than the lower limit value of the specified voltage supplied to the load device, and the state is And a control circuit section for executing a protection switching operation by the protection circuit section when the protection circuit section continues for a predetermined period. 2. The voltage regulator according to claim 1, wherein the control circuit section includes a predetermined alarm means, and prohibits the operation of the alarm means accompanying the execution of the protection switching operation. 3. The control circuit section, after the start of the protection switching operation, after a lapse of a predetermined standby period, the output voltage rises to a predetermined return condition value, and the state continues for a predetermined period. In this case, the voltage regulator according to claim 1 or 2, wherein an automatic return operation for canceling the protection switching operation by the protection circuit section is executed.