JPH02204928A - Electromagnetic switch with optical communication function - Google Patents

Abstract

PURPOSE:To monitor the operating condition of an electromagnetic switch at a remote control part by furnishing a built-in control circuit, whereby reading and storing the open/close condition of the main contact piece of an electromagnetic contactor and the operating condition of a thermal relay, and transmitting the stored data to the remote control part via an optical fiber in conformity to a command given from the remote control part via optical fiber. CONSTITUTION:At a current transformer 17 the current flowing in the main circuit is measured, and its secondary circuit current is A/D converted by a control circuit part 7 and read in. A part from operation of a thermal relay 15 this control circuit part 7 senses overcurrent condition upon this current value, or shuts the main circuit which is provided with a time limit characteristic in accordance with the overcurrent lasting situation, or otherwise judges if the pretrick condition is to be sensed, i.e., the condition a little before performing the shutting operation. Thus various types of conditions are sensed or judged in the control circuit part 7, wherein the condition is transmitted to a control circuit 14 of a remote control part by data transmission using optical fiber 10.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention has an optical communication function for controlling an electromagnetic switch via an optical fiber, and uses this communication function to transmit data such as the operating status of the electromagnetic switch. This invention relates to an electromagnetic switch that transmits data over long distances.

[Conventional technology]

A conventional electromagnetic switch turns on the main contact by energizing the electromagnetic coil with an electric signal, and shuts off the main contact by releasing the excitation.

Furthermore, an auxiliary contact is provided that operates in conjunction with the main contact of the electromagnetic switch, and this signal is used to configure a control circuit for the electromagnetic switch. Also, current transformers or voltage detection devices used with thermal relays and electromagnetic switches to electronically determine overcurrent conditions! It is connected by an electric wire to a remote control unit that controls the breaker.

(Problems to be Solved by the Invention) The conventional 'I!! magnetic opening/closing lid switch has the following problems.

■A lot of wiring work is required between the electromagnetic switch's electromagnetic coil, auxiliary contact, thermal relay, current transformer, and remote control unit.

■ Not only does the construction cost become expensive due to the increase in the number of wires, but
Wiring errors are likely to occur and maintenance work is time-consuming.

■In addition, these wirings become a source of noise generated from the switching of the main contactor of the electromagnetic switch or the electromagnetic coil, which can adversely affect other electronic devices.

As described above, conventional electromagnetic switches have various problems, but among these problems, the noise problem is the most important in recent years as the use of electronic equipment has increased, and noise countermeasures have become necessary. There is. As a countermeasure against this noise, it is possible to use optical fibers to send and receive signals, but simply applying optical signal transmission would require an optical fiber for each signal, so the cost of installing optical fibers and optical transmission would be high. There are disadvantages in that the required equipment increases and becomes expensive, and the equipment becomes larger.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the conventional device, to be able to control an electromagnetic switch using an optical fiber, and to monitor the operating state of the electromagnetic switch by a remote control unit via the optical fiber. An object of the present invention is to provide an electromagnetic switch with an optical communication function that can perform the following functions.

In order to achieve the above-mentioned object, the present invention has an optical communication function that controls an electromagnetic switch that is a combination of an electromagnetic contactor and a thermal relay from a remote control unit via an optical fiber! In the magnetic switch, at least the open/close state of the main contact of the electromagnetic contactor and the operating state of the thermal relay are read and stored in the electromagnetic switch, and the switching is transmitted from a remote control unit via an optical fiber; A cutoff command and a data request command are received, the electromagnetic coil of the electromagnetic contactor is energized or de-energized according to the turn-on and cutoff commands, and the stored data is sent to the remote control unit via an optical fiber according to the data request command. It is characterized by having a built-in control circuit unit that transmits data to.

[For production]

In the electromagnetic switch with an optical communication function according to the present invention, the electromagnetic switch is controlled to open and close by a closing and shutting command sent from a remote control unit via an optical fiber, and an electromagnetic switch stored in the electromagnetic switch Data such as the operating status of the device is transmitted to the remote controller via an optical fiber in response to a data request command from the remote controller.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings. FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention.

In Figure 1, what is 1? indicates the main contact of the magnetic contactor,
An auxiliary contact 2 that operates in conjunction with the main contact 1 is provided. The main contact 1 closes the main circuit when the electromagnetic coil 3 is excited, and opens the main circuit when the magnet coil 3 is de-energized. Resistors 4a and 4b are connected from the power supply side of the main contact l.
A full wave rectifier consisting of a diode bridge through the 4C
After full-wave rectification and smoothing with a smoothing capacitor 4d etc. to the DC terminal of the full-wave rectifier 4c, the three-terminal regulator 5
DC control using? 1iillX is being created. This DC power is supplied to a control circuit section 7 consisting of an LSI. This control circuit section 7 may be, for example, a one-chip microcomputer, or in some cases, a dedicated custom I
It may be composed of C. The control circuit section 7 performs various controls and judgments, and when exciting the electromagnetic coil 3, operates the transistor 6 to supply current. Also, LED 8
is a display element that displays the operating state of the electromagnetic switch, and blinks based on the determination result of the control circuit unit 7.

9 and 13 are light receiving circuits, 11 and 12 are light emitting circuits,
10 is an optical fiber, and 14 is a control circuit in the remote control section, which are necessary components for the communication means between the electromagnetic switch and the remote control section. The operation of this communication will be described later.

15 is a thermal relay combined with an electromagnetic contactor,
When an overcurrent flows through the main circuit, the contact 16 of the thermal relay is closed, and the contact signal is read into the control circuit section 7 and stored. When this contact 16 is closed and read into the control circuit section 7, a base current is supplied to the transistor 6, turning on the transistor 6, de-energizing the electromagnetic coil 3, and cutting off the electromagnetic switch.

17 is a current transformer that measures the current flowing in the main circuit;
The next circuit current is A/D converted and read into the control circuit section 7. Based on this current value, the control circuit section 7 detects an overcurrent state separately from the operation of the thermal relay 15, or depending on the continuation of the overcurrent state, shuts off the main circuit with time-limiting characteristics, or performs a shutoff operation. Judgments are made such as detecting a state a little earlier, that is, a pre-trip state.

On the 1st, the photocoupler connects the main contact 1 through the resistor 19.
Detects the load side voltage. The transistor output of this photocoupler 18 is read into the control circuit section 7, and even though the control circuit section 7 receives an input/interruption command from a remote control section, for example, and an excitation signal is given to the electromagnetic coil 3. Detects abnormal conditions such as when an electromagnetic switch does not close or shut off.

The control circuit section 7 detects or judges various states as described above, and these states are transmitted to the control 'n circuit 14 of the remote control section by data transmission using an optical fiber, which will be described later.

TC in the control circuit 14 of the remote control section is an input terminal for a trip coil signal, and the H signal applied to this input terminal means a cutoff signal, and the L signal means a cutoff signal. Further, by operating a functional Ceratos inch (not shown), a request for current detection data flowing to the load side of an electromagnetic switch, which will be described later, is requested.

Based on the transmission data from the electromagnetic switch, the control circuit 14 outputs the a signal when the auxiliary contact 2 is in the closed circuit state, and outputs the b signal when the auxiliary contactor 2 is in the open circuit state. Also, the operating state of the thermal relay 15 can be determined from the state of the contacts 16 by the current transformer 17.
It has a terminal that outputs the overcurrent cutoff state from the next circuit current. Furthermore, when the control circuit 14 transmits a command to turn on or cut off the electromagnetic switch, it checks the operation of the electromagnetic switch from the operating state of the photocoupler 18, and for example, even though the cutoff operation has been performed, voltage still exists. state i1 if
It has a terminal that outputs an L'2 abnormal signal. moreover,
Is there something wrong with the control circuit section 14? It has an output terminal that outputs U-phase and W-phase currents as analog signals based on the secondary circuit current of IL2317.

FIG. 2 shows the communication data of the data transmission performed between the electromagnetic switch mentioned above and the remote control section.

One unit character data of the communication data consists of a start bit, 8 data bits, and a stop bit. In order to improve communication compatibility, parity focusing and other various well-known means can be added, but their explanation will be omitted here. Figure 2 (^) shows the data sent from the control circuit 14 to the electromagnetic switch, which shows the current data ( ]) indicates the U-phase current, current data (2) indicates the W-phase current, and Figure 2 (8) indicates the signal sent from the electromagnetic switch to the control circuit 14. The start bit and stop bit are omitted here. It is shown as follows. The first 8 bits indicate various data stored in the control circuit section 7 described above, followed by current data (+).
, Current data is added according to the return request command in (2). This current data is an A/D converted digital value of 8
Transmitted as bits.

FIG. 3 shows the communication timing between the control circuit 14 and the electromagnetic switch. When the signal 14^ is transmitted from the control circuit 14, the signal 14B is returned from the control circuit section 7, and this communication is repeated. In other words, cyclic communication is carried out.

FIG. 4 shows a flowchart of the main operations of the control circuit section 7. When started, the initial state is set (
In step S1), the electromagnetic switch is set to an open state in which the electromagnetic coil 3 is de-energized. The optical signal from the control circuit 14 is monitored (Step S2), and when the signal is received, the electromagnetic coil 3 is controlled to be energized or de-energized (Step S5.
S6), after that, the state is determined whether there is a voltage drop, pre-trip, overcurrent cutoff, or an abnormal state by comparing the circuit voltage with the open/close state (step S7), and then a current data request command is issued from the control circuit 14. If there is a request, the current value is set (step S9), and then the status data, current value, etc. are shown in Figure 2 (B).
) Set the transmission data as shown in step 51.
0), Send data after timing adjustment (
Step S11.512).

Further, when the signal from the control circuit 14 is not received in step S2, the contact 16 of the thermal relay 15
Each status signal such as the status of the auxiliary contactor 2 is read (step 513), and if the contact 16 of the thermal relay 15 is on (step 514), the electromagnetic coil 3 is turned on to cut off the electromagnetic switch. If the current transformer 17 output indicates that the overcurrent should be cut off (step 516), the electromagnetic coil 3 is similarly deenergized (step 517), and step S
L2. After S17, the process returns to step S2, and the configuration is such that reception is always possible immediately.

〔Effect of the invention〕

As explained above, according to the present invention, in an electromagnetic switch with an optical communication function that controls an electromagnetic switch in which an electromagnetic contactor and a thermal relay are combined from a remote control unit via an optical fiber, the electromagnetic switch The controller reads and stores at least the open/close state of the main contactor of the electromagnetic contactor and the operating state of the thermal relay, and receives the closing and shutting commands and data request commands transmitted from the remote control unit via the optical fiber. , a built-in control circuit unit that energizes or de-energizes the electromagnetic coil of the electric IF contactor in response to a closing or shutting command, and transmits the stored data to a remote control unit via an optical fiber in response to a data request command. With this configuration, only a pair of optical fibers are required for the signal line connecting the remote control unit and the electromagnetic switch, reducing material and construction costs, construction work, and wiring space. This has the advantage of making inspection and maintenance easier. Also, status signals such as pre-trip status and abnormal operation. Since the signals can be transmitted simultaneously via optical fiber, it is possible to perform fine-grained control of the electromagnetic switch, and it is possible to detect serious troubles in advance and prevent them. It has the advantage of improving performance.

[Brief explanation of the drawing]

1 to 4 each show an embodiment of the present invention, and FIG. 1 is a circuit configuration diagram of an electromagnetic switch with an optical communication function, and FIG.
Figures (A) and (B) are configuration diagrams showing communication data, Figure 3 is a timing chart of communication data, and Figure 4 is a diagram showing the communication data.
The figure is a flowchart showing the operation of the control circuit section built into the SM switch. 3: Electromagnetic coil, 7: Control i11 circuit, 10 optical fiber, 14: Control circuit, 15: Thermal relay [Figure Adata Atsushi? Mouthful flash and - Rikiotsu-ku

Claims (1)

[Claims] 1) In an electromagnetic switch with an optical communication function that controls an electromagnetic switch in which an electromagnetic contactor and a thermal relay are combined from a remote control unit via an optical fiber, at least It reads and stores the open/close status of the contacts and the operating status of the thermal relay, receives closing/cutting commands and data request commands sent from the remote control unit via optical fiber, and generates electromagnetic signals in response to the closing/cutting commands. An electromagnetic switch with an optical communication function, which has a built-in control circuit section that energizes and de-energizes the electromagnetic coil of a contactor and transmits the stored data to a remote control section via an optical fiber in response to a data request command. .