JPH0794050A - Load control device - Google Patents

Abstract

PURPOSE:To save the consumption of power and suppress the deterioration by aging of an used electronic part by automatically interrupting a control power source to at least a display part by a control part not in operation. CONSTITUTION:A main circuit 23 has a main circuit equipment such as an electromagnetic contactor 25, and an operating device and control part 30 for operating a load 22, and the arithmetic logic circuit 31 of the control part 30 controls the main circuit equipment according to the input signal by the operating device and the magnitude of the main circuit current on the basis of a preliminarily stored control program. The judging circuit 41 of the control part 30 judges the presence or absence of an operation signal for opening and closing the electromagnetic contactor 25, and conducts the current carrying and interruption to the control power source in a load control device on the basis of this judgment. When the operation signal for opening the electromagnetic contact 25 is inputted to the judging circuit 41, a DC power source circuit 29 interrupts the control power source in the load control device excluding an input circuit 34, a detecting circuit 40 and the judging circuit 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load control device provided with an operating device for operating a load, in addition to a main circuit device for opening and closing a load.

[0002]

2. Description of the Related Art A control center is known as an example of a load side control device having an opening / closing and protection function for an electric motor or a resistive load. That is, in the control center, a plurality of units, in which devices such as an electromagnetic contactor, a circuit breaker for wiring, a current converter, and an auxiliary relay for control are gathered for each unit circuit, are housed in multiple stages, and each unit is started It is configured by providing a display operation panel including a display unit including a stop display lamp and the like, and an operation device including a start operation switch, a stop operation switch, and the like.

Further, in recent years, in order to easily cope with the specification change of the unit, by adopting an electronic application technique, a necessary function among a plurality of control and protection functions is appropriately set, added or changed. It is also possible to make it possible. That is, in this case, a logical operation circuit including a microcomputer is provided, and the theoretical operation circuit controls the main circuit device and the display unit according to the magnitude of the input signal from the operating device and the main circuit current detected by the current converter. The control mode can be changed flexibly by adopting the configuration for performing.

FIG. 4 schematically shows a configuration example of a control center which employs such a logical operation circuit.
That is, FIG. 4 shows an outline of the circuit configuration for one unit of the control center. The main circuit 3 between the three-phase power bus 1 and the electric motor 2 as a load is a main circuit device. The circuit breaker 4 for wiring, the electromagnetic contactor 5, the current converter 6 for main circuit current detection, and the zero phase current transformer 7 for ground fault current detection are provided. A primary side of the operating transformer 8 is connected to the load side of the wiring breaker 4, and control buses 9a and 9b are connected to the secondary side of the transformer 8.

The control unit 10 fed from the control buses 9a and 9b via a DC power supply circuit (not shown) is mainly composed of a logical operation circuit 11 composed of a microcomputer. The logical operation circuit 11 receives, through the input circuit 14, each ON signal from the starting operation switch 12, the stop operation switch 13, and the normally open auxiliary contact 5a of the electromagnetic contactor 5, which are operating devices. Each signal from the current converter 6 and the zero-phase current transformer 7 is converted into an A / D conversion circuit 1
5, the coil 5b for operation of the electromagnetic contactor 5 is controlled via the output circuit 16 to switch on and off.

The memory circuit 17 stores a control program and function data for executing protection operations such as overload, open phase, undercurrent, ground fault, and control operations such as instantaneous power failure restart and instantaneous restart. Therefore, the logic control circuit 11
The protection operation and the control operation are executed based on the control program, the function data and the input signal. Setting circuit 1
The numeral 8 is composed of a large number of selection switches (not shown) so that the function data stored in the memory circuit 17 can be set and selected as desired at the installation site of the control center.

Since the logical operation circuit 11 thus constructed by the microcomputer is used to control the main circuit equipment and the like, for example, even when the specifications of the unit are changed, the control program for the logical operation circuit 11 is controlled. You will be able to deal with it easily just by changing.

[0008]

By the way, there are various wastes in operating such a control center. In particular, the control device for the load that does not operate for a long period of time has the control power supply alive even though it is not operating. For example, a control device for a load operated in conjunction with the load, a load operated for backup in the event of a failure, or the like is uncertain when to start the operation, so it is necessary to keep the control power supply alive. For loads that have not been operated for a long period of time, it is necessary to perform normal operation after conducting a test operation to check for abnormalities.

The present invention has been made in consideration of the above circumstances, and a first object of the present invention is to reduce power consumption by automatically disconnecting a control power source for at least a display unit from a load control device which is not in operation. Another object of the present invention is to provide a load control device capable of suppressing aged deterioration of electronic components used together with the load control device.

A second object of the present invention is, in addition to the first object, a load for periodically energizing a control power source to diagnose a circuit abnormality or the like, and to issue an alarm in advance if there is an abnormality. To provide a control device.

[0011]

SUMMARY OF THE INVENTION The present invention provides a main circuit device such as an electromagnetic contactor interposed in a main circuit between a power bus and a load, an operating device for operating the load, and an input by the operating device. In a load control device provided with a logical operation circuit that controls a main circuit device according to the magnitude of a signal and a main circuit current based on a prestored control program, the presence or absence of an operation signal for opening and closing an electromagnetic contactor is determined. A determining means and a DC power supply circuit for turning on and off the control power supply in the load control device based on the determination are provided, and when the determining means determines that there is no operation signal for closing the electromagnetic contactor, it determines the determining means. Except for this, the control power supply is turned off, and when it is determined that there is an operation signal for closing the electromagnetic contactor, the control power supply is energized.

In this case, while the judging means judges that there is no operation signal for closing the electromagnetic contactor, the judging means periodically outputs a signal to the DC power supply circuit to energize the inside of the load control device. The logical operation circuit can be configured to determine whether each circuit inside the load control device is functioning normally.

Further, a main circuit device such as a circuit breaker for wiring interposed in the main circuit between the power source bus and the load, an operating device for operating the load, and an input signal and a main circuit current by the operating device In a load control device provided with a logical operation circuit for controlling a main circuit device according to a control program stored in advance, a signal for an auxiliary contact interlocking with opening and closing of a wiring breaker is input to the wiring breaker. When the determination means determines that the wiring breaker is open, a determination means for determining the opening and closing of the load control circuit and a DC power supply circuit for disconnecting the control power supply in the load control device based on this determination are provided. The control power supply other than the determination means is cut off, and when it is determined that the wiring breaker is closed, the control power supply is energized.

In this case, while the judging means judges that the wiring breaker is open, the judging means periodically sends a signal to the DC power supply circuit to energize the control power supply in the load control device and to make an electromagnetic contactor. Can be energized to determine whether or not each circuit inside the load control device is functioning normally and whether or not the electromagnetic contactor is functioning normally by the logical operation circuit.

[0015]

In the load control device according to the first aspect of the present invention, since the DC power supply circuit energizes the control power supply only when an operation signal for closing the electromagnetic contactor is input, power consumption and power consumption are reduced. Aging deterioration of electronic components can be suppressed.

According to another aspect of the load controller of the present invention,
The load control device is periodically energized to perform self-diagnosis as to whether or not there is an abnormality in each internal circuit. If there is an abnormality, an alarm is issued and maintenance can be performed when operation is required.

According to another aspect of the load control apparatus of the present invention,
Since the DC power supply circuit energizes the control power supply only when an operation signal for closing the circuit breaker for wiring is input, the same operation as in claim 1 is achieved. In the load control device according to the fourth aspect of the present invention, when the circuit breaker for wiring is opened, it is energized periodically, so that self-diagnosis of the entire control circuit can be performed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a control center will be described below with reference to FIGS. First, a first embodiment will be described with reference to FIGS.

That is, FIG. 1 shows a control center 1
The circuit configuration for the unit is shown. In FIG. 1, a main circuit 23 is formed between a three-phase power bus 21 and an electric motor 22 which is a load, and the main circuit 23 has a wiring breaker 24 which is a main circuit device. , Electromagnetic contactor 25, current converter 26 for detection that generates a voltage signal according to the main circuit current, and zero-phase current transformer 27 for ground current detection
Is provided. The primary side of the operating transformer 28 is connected to the power bus 21 side of the circuit breaker 24 in the main circuit 23, and the control buses 29a and 29b are connected to the secondary side of the transformer 28. ing.

The control section 30 fed from the control buses 29a and 29b through the DC power supply circuit 29 is mainly composed of a logical operation circuit 31 composed of a microcomputer. The logical operation circuit 31 outputs ON signals from a start operation switch 32 and a stop operation switch 33, which are operating devices, and ON signals and OFF signals from a normally open auxiliary contact 25a included in the electromagnetic contactor 25. Input circuit 3
4 and receives the current converter 26 and the zero-phase current transformer 2
Each signal from 7 is received via the A / D conversion circuit 35,
Operation coil 2 of electromagnetic contactor 25 via output circuit 36
5b is designed to control the disconnection. The logical operation circuit 31 also controls the display contents, which will be described later, by the display unit 39.

The storage circuit 37 stores a control program and function data for executing protection operations such as overload, open phase, undercurrent, ground fault, and control operations such as instantaneous power failure restart and timed restart. Therefore, the logic control circuit 31
The protection operation and the control operation are executed based on the control program, the function data and the input signal. Setting circuit 3
Reference numeral 8 is composed of a large number of selection switches not shown so that the function data stored in the storage circuit 37 can be set and selected as desired at the installation site of the control center.

The detection circuit 40 includes a starting operation switch 3
2. The ON signal and the OFF signal from the stop operation switch 33 are taken in through the input circuit 34,
Based on these signals, the status signal S as shown in FIG.
Output c. That is, the state signal Sc is a signal in which a high level state indicates an energization command of the electromagnetic contactor 25, and a low level state indicates a disconnection command of the electromagnetic contactor 25.

The determination circuit 41 generates a signal in synchronization with the rising and falling of the state signal Sc, and supplies the synchronization signal to the DC power supply circuit 29 as a signal indicating the determination result of load operation / stop. . The DC power supply circuit 29 supplies at least control power to the display unit 39 based on the falling sync signal from the determination circuit 41 except for the input circuit 34, the detection circuit 40 and the determination circuit 41 as the determination means in the control unit 30. It is designed to turn on and off electricity.

Therefore, when the load 22 is stopped by the stop command, the control power supply from the DC power supply circuit 29 to the display unit 39 is cut off, so that the power consumption of the control unit 30 can be suppressed and the load can be used. It is possible to suppress the heat generation of the electronic component being operated and prevent the electronic component from aged deterioration.

In this case, not only the power consumption of the control unit 30 can be suppressed, but also the electrical connection with each unit of the control unit 30 can be confirmed. That is, while the detection circuit 40 outputs a low-level signal indicating the disconnection command of the electromagnetic contactor 25, the determination circuit 4
1 periodically supplies the rising synchronization signal of the state signal Sc to the DC power supply circuit 29 and also to the logical operation circuit 31. On the other hand, the logical operation circuit 31 has an input circuit 34.
If the signal is taken in via the signal and does not indicate the energization command of the electromagnetic contactor 25, the determination circuit 41
The logical operation circuit 31 confirms continuity with each unit of the control unit 30 based on a periodic signal from the display unit 39, and if there is an abnormality, the display unit 39
To send an alarm display. If there is no abnormality, a signal is sent to the judgment circuit 41. The determination circuit 41 supplies a falling synchronizing signal to the DC power supply circuit 29 based on the signal indicating that there is no abnormality, and the DC power supply circuit 29 disconnects at least the control power supply to the display unit 39.

FIG. 3 shows another embodiment of the present invention.
Input the state signal S to the closing auxiliary contact 24a of the circuit breaker 24 for wiring.
It is intended to be used as c. Circuit breaker 2
The auxiliary closing contact 24a of No. 4 has a control bus 29a and an input circuit 34.
And the on / off signal is output to the logical operation circuit 31 and the detection circuit 40 via the input circuit 34. The detection circuit 40 receives the status signal S based on the ON and OFF signals.
Then, the decision circuit 41 outputs a rising or falling synchronizing signal. The DC power supply circuit 29 is energized by the signal from the determination circuit 41 when the circuit breaker 24 for wiring is closed, and when the circuit breaker 24 for wiring is closed, the input circuit 34, the detection circuit 40, and the determination circuit 41 as the determination means in the control unit 30. The power is cut off except for. When the circuit breaker 24 for wiring is opened and the DC power supply circuit 29 is cut off, the determination circuit 41 gives a rising synchronizing signal Sc to the DC power supply circuit 29 periodically to energize the power supply output to each circuit and at the same time the logical operation circuit. Send a signal to 31. At this time, the OFF signal of the closing auxiliary contact 24a of the circuit breaker 24 for wiring is input to the logical operation circuit 31 at this time, so that the logical operation circuit 31 confirms continuity with each unit of the control unit 30. Since the wiring breaker 24 is open, the load 22 is not energized even when the electromagnetic contactor 25 is operated. Therefore, the operating coil 25b of the electromagnetic contactor 25 is energized via the output circuit 36. The operation of the electromagnetic contactor 25 is confirmed, and the current flowing in the operating coil 25b and the normally-closed auxiliary contact 2 input via the input circuit 34
It is determined whether or not the electromagnetic contactor 25 is functioning normally by the time until the input of 5a, or an input signal from a sensor that detects vibration or sound (not shown). A signal is sent to the display unit 39 to display an alarm. After the series of confirmations, if there is no abnormality, a signal is sent from the logical operation circuit 31 to the determination circuit 41, the determination circuit 41 outputs the falling synchronizing signal to the DC power supply circuit 29, and the DC power supply circuit 29 sends signals to each circuit. Turn off the control power.

In this embodiment, maintenance can be facilitated by periodically performing self-diagnosis not only in the load control device but also in the entire control circuit for a load that is not operated for a long period of time.

[0028]

As described above, according to the present invention, by disconnecting the control power supply while the load is stopped, it is possible to suppress not only the power consumption but also the heat generation to suppress the aging deterioration of electronic components. It is possible to expect an excellent effect that maintenance can be facilitated by regularly performing self-diagnosis.

[Brief description of drawings]

FIG. 1 is a schematic circuit configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a status signal.

FIG. 3 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 4 is a view corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

In the figure, 21 is a power bus, 22 is a load, 23 is a main circuit, 2
4 is a circuit breaker for wiring, 25 is an electromagnetic contactor, 29 is a DC power supply circuit, 30 is a control unit, 31 is a logical operation circuit, 36 is an output circuit, 39 is a display unit, 40 is a detection circuit, and 41 is a determination circuit. Show.

Claims (4)

[Claims] 1. A main circuit device such as an electromagnetic contactor interposed in a main circuit between a power bus and a load, an operating device for operating the load, and a magnitude of an input signal and a main circuit current by the operating device. In a load control device provided with a logical operation circuit for performing control of the main circuit device in accordance with a control program stored in advance, determination means for determining the presence or absence of an operation signal for opening and closing the electromagnetic contactor, and Based on the judgment, a DC power supply circuit for connecting and disconnecting the control power supply in the load control device is provided, and when the judgment means judges that there is no operation signal for closing the electromagnetic contactor, the control excluding the judgment means A load control device configured to energize a control power supply when it is determined that there is an operation signal for turning off the power supply and closing the electromagnetic contactor. 2. While the determination means determines that there is no operation signal for closing the electromagnetic contactor, the determination means periodically outputs a signal to the DC power supply circuit to energize the load control device, 2. The load control device according to claim 1, wherein the logical operation circuit is configured to determine whether or not each circuit inside the load control device is functioning normally during energization. 3. A main circuit device such as a circuit breaker for wiring interposed in a main circuit between a power bus and a load, an operating device for operating the load, and an input signal and a main circuit current by the operating device. In a load control device provided with a logical operation circuit that controls the main circuit device according to the size based on a control program stored in advance, by inputting a signal of an auxiliary contact that is interlocked with opening and closing of the wiring breaker. A determination means for determining whether the circuit breaker for wiring is opened or closed, and a DC power supply circuit for connecting and disconnecting the control power supply in the load control device based on this determination are provided, and the determination means determines that the circuit breaker for wiring is open. In this case, the load side control device is configured to turn off the control power supply except for the determination means, and to energize the control power supply when it is determined that the wiring breaker is closed. 4. The determination means periodically sends a signal to a DC power supply circuit while the determination means determines that the circuit breaker for wiring is open, and the control power source is energized in the load control device, and the electromagnetic contactor is also provided. And a logical operation circuit is used to determine whether each circuit inside the load control device is functioning normally and whether the electromagnetic contactor is functioning normally. The load control device according to claim 3.