JPH07143619A - Load control system - Google Patents

Abstract

PURPOSE:To easily output maintenance data for a specific load in response to a maintenance person's request. CONSTITUTION:The load control system comprises a controller 11 for controlling a main circuit implement such as an electromagnetic contactor 4, etc., responsive to an input signal of an operating unit such as a starting switch and magnitude of a main circuit current based on a program which is previously stored. The controller 11 has a set memory 18 for accumulating and storing maintenance data such as a load current, a load operating time, switching times of the contactor, etc., and a communicating circuit 20 for communicating the data with an exterior irrespective of whether a load 2 is operating or not. A personal computer 21 is connected to the circuit 20 to output the data of a specific load.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A control center is known as an example of a load control system having an opening / closing function and a protection function for an electric motor or a resistive load. That is, in the control center, a plurality of control units in which devices such as electromagnetic contactors, circuit breakers, current converters, auxiliary control relays, etc. are grouped into unit circuits are stored in multiple stages, and each control unit It is configured by providing a display operation panel including a display device including a start / 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 control unit, by adopting an electronic application technique, necessary functions among a plurality of control and protection functions are appropriately set, added, It is also possible to have a configuration that can be changed. In other words, in this case, a control circuit centered on a logical operation circuit composed of a microcomputer is provided, and the control circuit is used to control the input signal from the operating device and the main circuit current detected by the current converter. The control mode can be flexibly changed by adopting a configuration for controlling the main circuit device and the display device.

[0004]

By the way, in such a control center, although the control circuit has a program for controlling and protecting the load such as overload current protection, the state of the load and the driving of the load are driven. Generally, the maintenance data such as the status of the power supply equipment to be stored is not stored. For this reason, it was not possible to confirm the status of the load and the status of the power supply equipment that drives the load. In this case, it is considered to control and protect the status of all loads by using transmission technology, but in the case of a large number of loads such as power plants, oil plants and chemical plant factories, its operation system is There was a problem that the system had to be changed in order to obtain maintenance data for a specific load established.

The present invention has been made in consideration of the above circumstances, and an object thereof is to perform load control by which maintenance data such as a status confirmation for a specific load and a status grasp of a power supply facility can be easily taken out in response to a request from a maintenance staff. In providing the system.

[0006]

SUMMARY OF THE INVENTION A load control system according to the present invention includes a main circuit device such as an electromagnetic contactor and a current transformer interposed in a main circuit between a power source bus and a load, and switching and protection of the load. An operating device for performing, and a control circuit for controlling the control of the main circuit device according to the magnitude of the input signal and the main circuit current of the operating device based on a program stored in advance, the control circuit Within the load current,
A means for accumulating and storing maintenance data such as load operating time and the number of times of opening and closing of the electromagnetic contactor is provided, and a communication means for communicating maintenance data to the outside regardless of whether the load is operating or not. Is characterized by. (Claim 1) In this case, a display device or an output device can be connected to the communication means. (Claim 2) A personal computer can be used as a display device or an output device. (Claim 3)

[0007]

In the load control system of the present invention, since the control circuit accumulates and stores the maintenance data and further has the communication means, the communication means of the control circuit is separately provided for a specific load. The maintenance data can be easily taken out only by connecting the prepared display device or output device, for example, a portable laptop personal computer or the like.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 is a three-phase main circuit that supplies power to an induction motor 2 that is a load.
The main circuit device includes a circuit breaker for wiring 3, an electromagnetic contactor 4, a current transformer 5 as a current converter for detecting a main circuit current, and a zero-phase current transformer 6 for detecting a zero-phase current of the main circuit. Has been intervened as. The primary winding 7a of the operating transformer 7 is connected between the two phases of the main circuit 1 between the load side of the wiring breaker 3 and the power source side of the electromagnetic contactor 4. The output voltage of the secondary winding 7b of the operating transformer 7 is applied to the bus bar 8 as a power source for the operating circuit. The bus bar 8 has a coil 4a and an auxiliary contact 4b of the electromagnetic contactor 4 so that the bus bar 8 is used as one power line.
One end of each of the start operation switch 9 and the stop operation switch 10 is connected, and the other end of the coil 4a of the electromagnetic contactor 4 is connected to the output circuit 12 of the control circuit 11, and the auxiliary contact 4b, the start operation switch 9, and the stop operation switch. The other end of 10 is connected to the input circuit 13 of the control circuit 11. The control circuit 11 is mainly composed of a theoretical operation circuit 14 composed of a micro computer, and digitally converts an analog signal detected by the current transformer and the zero-phase current transformer 6 in accordance with the magnitude of the main circuit current. A current detection circuit 15 including an A / D converter for converting into a signal, a signal output from the current detection circuit 15 is input, and an analog signal detected by the temperature sensor 16 according to a temperature value is converted into a digital signal. A signal from the temperature detection circuit 19 including an A / D converter is input to monitor the abnormality of the main circuit current and the temperature of the device, and when the abnormality is determined, the electromagnetic contactor 4 is opened / closed. A logical operation circuit 14 for outputting a command to the output circuit 12,
A display circuit 17 for displaying the main circuit current value and the cause of abnormality of the main circuit 1 by a signal from the logical operation circuit 14 and a condition matching the rating of the induction motor 2 are input to the logical operation circuit 14 using a dip switch or the like. The setting storage circuit 18 including a non-volatile memory is provided. Then, the logical operation circuit 14 is configured to execute a protection operation and a control operation based on each signal given from the current detection circuit 15 and the input circuit 13 by a program stored in the setting storage circuit 18 in advance. The power of the control circuit 11 is supplied from the tertiary winding 7c which is insulated from the secondary side of the operation transformer 7 in order to prevent intrusion of switching noise generated by the coil 4a of the electromagnetic contactor 4. Has become.

The logical operation circuit 14 calculates the load current, the operating time, the number of times the electromagnetic contactor is opened and closed, the temperature, etc. by the signal from the current detection circuit 15, the temperature detector 19 and the signal from the input circuit 13, and the setting storage circuit. Then, the setting storage circuit 18 accumulates and stores these maintenance data. The setting storage circuit 18 is provided with a communication circuit 20 as a communication means, and a display device or an output device 21 (hereinafter referred to as a display / output device) separately prepared is connected to an output terminal of the communication circuit 20. This makes it possible to retrieve various maintenance data such as load current, load operating time, device temperature, and number of electromagnetic contactor switching operations.

FIG. 2 is a schematic diagram showing a load control system having the circuit configuration of FIG. In FIG. 2, the display / output device 21 is shown as a laptop personal computer. FIG. 3 is a schematic diagram of the control center 22. The control center 22 accommodates a plurality of control units corresponding to a large number of unit circuits, and the control circuit of each control unit is provided with the output terminal of the communication circuit 20 shown in FIG. Therefore, by connecting the personal computer 21 to the output terminal of the communication circuit 20 of the control unit for a specific load, maintenance data such as the load current of the specific load, the operating time, the number of times the electromagnetic contactor is opened and closed, and the temperature can be easily retrieved. be able to.

It should be noted that the personal computer 21 may be used to input the conditions according to the rating of the induction motor 2 to the setting storage circuit 18. It is also possible to use the personal computer 21 to input maintenance data, such as insulation resistance test results, which has not been accumulated or stored in the setting storage circuit 18, into the memory.

[0012]

According to the present invention, for a specific load,
Various maintenance data such as the load current, the operating time, the number of times the electromagnetic contactor is opened and closed, and the temperature can be easily retrieved as needed.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram of a load control system having the circuit configuration of FIG.

FIG. 3 is a schematic diagram showing a state where the load control system shown in FIG. 2 is applied to a control center.

[Explanation of symbols]

1 is a main circuit, 4 is an electromagnetic contactor, 5 is a current converter, 6 is a zero-phase current transformer, 11 is a control circuit, 14 is a logical operation circuit, 15
Is a current detection circuit, 16 is a temperature sensor, 19 is a temperature detection circuit, 20 is a communication circuit, 21 is a display / output device (personal computer), and 22 is a control center.

Claims (3)

[Claims] 1. A main circuit device such as an electromagnetic contactor and a current transformer interposed in a main circuit between a power bus and a load, an operating device for opening and closing and protecting the load, and an input signal for the operating device. A control circuit for controlling the control of the main circuit device according to the magnitude of the main circuit current based on a pre-stored program, wherein the control circuit has a load current, a load operating time, and Load control characterized in that a means for accumulating and storing maintenance data such as the number of times of opening and closing of the electromagnetic contactor is provided, and a communication means for communicating maintenance data to the outside regardless of whether the load is operating or not. system. 2. The load control system according to claim 1, wherein a display device or an output device is connected to the communication means. 3. The load control system according to claim 2, wherein the display device or the output device is a personal computer.