JPS5934217Y2 - selection control circuit - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a selection control circuit for circuit breakers, disconnectors, etc., which is highly reliable.

The recent trend of control devices is to reduce their size, and for this reason, in recent control circuits for circuit breakers, disconnectors, etc., position selection opening/closing is provided for each circuit breaker, disconnector, etc. The position of each device is selected depending on the device, and one main control switch is provided in common for each of these positions.
A common method is to issue control commands to each device using this main control switch.

However, because the appliances and circuit networks that make up these devices are designed to be miniaturized, their electrical performance is somewhat inferior to the original appliances and circuit networks, and in order to obtain the desired electrical performance, the circuit It tends to complicate the configuration.

As a result, it can be said that the reliability is somewhat inferior.

FIG. 1 shows an example of a conventional circuit.

This circuit is the most basic selection control circuit configured with a first-come, first-served priority circuit.

In FIG. 1, if one control is to be performed on a controlled device, first, the position selection switch BS1 is selected, and thereby the auxiliary relay 2 is operated to close the normally open contact 2a.

In this state, by operating the main control switch MS, the auxiliary relay 1 is operated, the normally open contact 1a is closed, and the equipment is connected to the auxiliary relay 1.
Issue a control command to.

After the control is completed, the main control switch MS is reset, and then the position selection switch BS1 is also reset, and the series of control operations is completed.

In this case, a malfunction in the main control switch circuit, for example, a mechanical reset failure of the main control switch MS or a malfunction of the auxiliary relay 1 due to insulation breakdown, etc., occurs when the main control switch MS is not operated. If you do so, the IIJ
Position selection switch BS2 of 2 will be selected for equipment III, and since auxiliary relay 1 is already operating, a control command will be issued to 2 of the controlled equipment at the same time as auxiliary relay 2 is selected. This is not a so-called two-stage control, but a one-stage control in which a control command is issued at the same time as position selection, which causes various problems.

In other words, since the two-stage control is different from the one intended by the operator, unexpected accidents are likely to occur.Furthermore, if the problem of multiple position selections overlaps, the auxiliary relay contacts may burn out due to multiple control or multiple selection return commands. do.

In addition, if the controlled equipment is a breaker intended for paralleling different systems, there may be a situation in which forced paralleling is performed without checking the voltage difference, frequency difference, phase difference, etc. between the two systems. There is also a risk of causing disturbance.

In other words, when paralleling different systems, first select the positions of the controlled devices to be paralleled, visually check the voltmeter, frequency system, and synchronization tester, and after confirming that the predetermined conditions are met, open/close the main control. Therefore, when the above-mentioned malfunction occurs, visual confirmation cannot be made.
1 Forced control.

As described above, the conventional method is likely to cause various problems.

An object of the present invention is to provide a selection control circuit that prevents the occurrence of malfunctions by blocking selection control that is likely to be performed immediately after such a problem occurs.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, the main control switch MS is connected to the auxiliary relay 1 which is activated by this selection, and further to the controlled equipment 1. There are position selection switches BS1 and BS2 corresponding to 2 and auxiliary relays 2 and 3 that operate according to position selection.

X is a malfunction detection relay, which closes contact 1a and closes contact 2.
When b and 3b are closed, it is excited from the P and N power supplies.

When this relay X operates, it holds itself and also sounds the alarm of BZ.

When controlling the controlled device 1, the position selection switch BS1 is selected and then the auxiliary relay 2 is operated.

At this time, the normally open contact 2a is closed, and then the normally open contact 1a of the auxiliary relay 1, which is operated under the control of the main control switch MS, is closed, and a control command is issued to the controlled device 1.

At this time, if the malfunction detection relay X of the main control switch circuit detects a malfunction and presses the button, the normally closed contact xb is open, so
The control command is blocked.

Position selection switch BS1. The auxiliary relays 2 and 3 operated by the BS2 are inoperative during normal operation, and the normally closed contacts 2b and 3b are closed.

In this state, the non-operation of the auxiliary relay 1 of the main control switch circuit is normal; if a malfunction occurs, the normally open contact 1a is closed, so the auxiliary relay X detects this and the position The selection circuit is opened to prevent position selection.

Furthermore, the alarm BZ gives a warning to the operator. In this way, the standard two-stage control of first selecting the position and then controlling the main control switch is ensured, so that the various problems described above can be prevented.

This is useful for improving the reliability of a device constructed from one main control switch and a large number of position selection switches as described above.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a conventional example, and FIG. 2 is a circuit diagram of an embodiment of the present invention. MS...Main control switch, BSl, BS2...Position selection switch, 1, 2, 3, X...Auxiliary relay B
Z...Alarm.

Claims (1)

[Scope of utility model registration request] AND condition is established between a main control switch, a selection device for controlled equipment provided corresponding to the controlled equipment, a normally open contact that responds to the main control switch, and a normally open contact that responds to the selection device. In the selection control device that outputs control commands to the controlled equipment, the normally open contact of the auxiliary relay that responds to the main control switch and the selection device of each controlled equipment An auxiliary relay for fault detection is provided in series with a series circuit of normally closed contacts, and a self-holding contact of this auxiliary relay for fault detection is connected in parallel with a series circuit of normally closed contacts that responds to the selection device of the controlled device. , and a normally closed contact that opens when the malfunction detection auxiliary relay is operated is connected in series to a control command circuit for a controlled device.