CN203788052U - Relay protection voltage switching monitoring circuit - Google Patents

Abstract

A relay protection voltage switching monitoring circuit, including I bus isolating switch normally open contact, I bus voltage indicator, I bus voltage switching relay without reset coil, I bus voltage switching relay with reset coil, I bus isolating switch Normally closed contact and resistor R1; II bus isolating switch normally open contact, II bus voltage indicator light, II bus voltage switching relay without reset coil, II bus voltage switching relay with reset coil, II bus isolating switch normally closed contact and Resistor R2, between the positive power supply of the signal and the simultaneous action input end of the switching relay, is connected with a series circuit composed of the contacts of the Ⅰ mother voltage switching relay and the Ⅱ mother voltage switching relay contacts, which are connected in parallel at both ends of the series circuit with a return coil A series circuit composed of the contacts of the Ⅰ bus voltage switching relay and the contacts of the Ⅱ bus voltage switching relay with a reset coil. During operation, it is convenient for operating personnel to discover and deal with abnormal situations in time.

Description

Relay Protection Voltage Switching Monitoring Circuit

technical field

The utility model relates to a relay protection voltage switching monitoring circuit.

Background technique

For the electrical components connected to the double busbar system, when the two sets of busbars are operated in parallel (for example, the bus tie circuit breaker is disconnected), in order to ensure that the primary system and the secondary system maintain corresponding voltages, in order to avoid protection or automatic devices Misoperation, refusal to operate, demand protection and the secondary voltage circuit of the automatic device are switched synchronously with the primary operation mode of the main wiring. Use the two auxiliary contacts of the isolating switch in parallel to start the voltage switching intermediate relay, and use its contacts to realize the automatic switching of the voltage circuit. In recent years, due to the contact problem of the auxiliary contact of the isolating switch and the wiring debugging of the protection personnel, the voltage switching circuit is wrongly paralleled, resulting in the loss of voltage of the protection device, and the secondary reverse charging of the voltage transformer of the primary power failure. And it is more harmful, resulting in protection refusal or misoperation, or serious personal and equipment hazards. For example, the 220kv system of a 220kv substation performs bus-inverting operation. Its voltage switching monitoring circuit consists of Ⅰ bus voltage switching relay contact 1YQJ1 and Ⅱ bus voltage switching relay contact 2YQJ1. The two contacts are relay contacts without holding, as shown in Figure 1 As shown, after all the 220kv interval equipment is reversed from the II bus to the I bus, and the 220kv bus tie switch is disconnected to power off the 220kv II section bus, all the operating 220kv equipment protection devices will send out "PT voltage abnormality" alarm signal. After checking 220kvⅠ, Ⅱ female PT secondary voltage all lost. On-site inspection found that the 1YQJ relay and the 2YQJ relay in the voltage switching circuit of 220kv Line A are both in the action state, so that the 220kv I and II bus voltages are paralleled through the voltage switching circuit of Line A. Line A runs on mother I, and it is correct that the action of contact 1YQJ in all voltage switching circuits is connected, but contact 2YQJ should not act. In the follow-up inspection, it was found that the normally closed auxiliary contact of the line II bus isolation knife switch was not connected because the conversion was not in place. After the interval of line A is switched from 220kv Ⅱ bus to Ⅰ bus, the normally closed auxiliary contact of the line Ⅱ bus switch is not closed. From the voltage switching circuit diagram, it can be seen that the type II bus voltage switching relay with reset coil is still in the on state, and the type II bus voltage switching relay without reset coil is in the off state, the "II bus running light" is off, and the "switching Simultaneous action of relays" signal is not issued. Therefore, the secondary voltages of 220kv I and II female PTs are paralleled through the voltage switching circuit of Line A. During the operation of bus inversion, the operating personnel did not pay attention to disconnect the secondary circuit breaker of the II bus PT which was powered off. When the 220kv bus tie switch is separated, the secondary voltage of bus I will be reversely charged to the power-off bus II PT through the parallel point, causing the secondary voltage air switch of 220kv bus I and II PT to trip.

Contents of the invention

The technical problem to be solved by the utility model is to provide a relay protection voltage switching monitoring circuit, which can reflect the state of the auxiliary contact, facilitate the operator to monitor and eliminate hidden dangers in time; facilitate the operator to find and deal with abnormal conditions in time, and select high-quality Auxiliary contacts of the isolating switch, and strengthen the regular maintenance of the isolating switch to keep it in good condition.

The technical solution of the utility model is:

A relay protection voltage switching monitoring circuit, including the normally open contacts of I bus isolating switches connected in series, I bus voltage indicator light, I bus voltage switching relays 1YQJ1~1YQJ3 without reset coils, and I bus voltage switching relays with reset coils 1YQJ4～1YQJ7, and the normally closed contact of I mother isolating switch and resistor R1 connected in series, said resistance I is connected to the reset coil of I mother voltage switching relay 1YQJ4～1YQJ7 with reset coil, the normally open contact of I mother isolating switch and I The common terminal of the normally closed contact of the mother isolating switch is connected to the positive power supply; the normally open contact of the II mother isolating switch in series, the II mother voltage indicator light, the II mother voltage switching relay 2YQJ1~2YQJ3 without a reset coil, and the II bus voltage switch relay with a reset coil The mother voltage switching relays 2YQJ4~2YQJ7, and the normally closed contact of the II mother isolating switch and the resistor R2 connected in series, the other end of the resistor R2 is connected to the return coil of the II mother voltage switching relay 2YQJ4~2YQJ7 with a reset coil, and the II mother The common terminal of the normally open contact of the isolating switch and the normally closed contact of the isolating switch of the Ⅱ mother is connected to the positive power supply, and the contact 1YQJ1 of the Ⅰ mother voltage switching relay and the Ⅱ mother voltage switching are connected between the positive power supply of the signal and the simultaneous action input end of the switching relay. The special feature of the series circuit composed of relay contacts 2YQJ1 is that the two ends of the series circuit are connected in parallel with another relay contact 1YQJ5 composed of I mother voltage switching relay contact 1YQJ5 with reset coil and II mother voltage switch relay contact 2YQJ5 with reset coil. a series loop.

The beneficial effects of the utility model are:

On the basis of the original series circuit, another series circuit composed of I bus voltage switching relay contact 1YQJ5 with reset coil and II bus voltage switching relay contact 2YQJ5 with reset coil is connected in parallel. In this way, if the isolating switch can be switched normally during operation, the signal of "simultaneous action of switching relays" will automatically reset, and when the switching is not in place, the signal will not reset, which is convenient for operators to find and deal with abnormal situations in time.

Description of drawings

Figure 1 is a schematic diagram of the original relay protection voltage switching monitoring circuit;

Fig. 2 is the schematic circuit diagram of the utility model.

Detailed ways

As shown in Figure 2, the relay protection voltage switching monitoring circuit includes the normally open contact 1 of the I bus isolating switch in series, the I bus voltage indicator 1XD, the I bus voltage switching relay 1YQJ1~1YQJ3 without a reset coil, and the Coil I bus voltage switching relays 1YQJ4~1YQJ7, and I bus isolation switch normally closed contact 2 and resistor R1 in series, the other end of the resistor R1 is connected to the reset coil of I bus voltage switching relays 1YQJ4~1YQJ7 with reset coil Above, the common terminal of the normally open contact 1 of the Ⅰ female isolating switch and the normally closed contact 2 of the Ⅰ female isolating switch is connected to the positive power supply; the normally open contact 3 of the Ⅱ female isolating switch in series, the Ⅱ female voltage indicator 2XD, without a reset coil II bus voltage switching relays 2YQJ1~2YQJ3, II bus voltage switching relays 2YQJ4~2YQJ7 with reset coil, and the normally closed contact 4 of the II bus isolating switch and resistor R2 connected in series, the resistor R2 is connected to the II bus with reset coil On the return coils of the voltage switching relays 2YQJ4~2YQJ7, the common terminals of the normally open contact 3 of the Ⅱ female isolating switch and the normally closed contact 4 of the Ⅱ female isolating switch are connected to the positive power supply, and the positive power supply 5 of the signal and the switching relay act simultaneously to open The input terminal 6 is connected with a series circuit composed of I bus voltage switching relay contact 1YQJ1 and II bus voltage switching relay contact 2YQJ1, and a series connection of I bus voltage switching relay contact 1YQJ5 with reset coil and II bus voltage switch relay contact 1YQJ5 with reset coil. Switch another series loop formed by relay contacts 2YQJ5, and connect the two series loops in parallel.

Claims (1)

1. A relay protection voltage switching monitoring circuit, including the normally open contacts of the I bus isolating switch in series, the I bus voltage indicator light, the I bus voltage switching relay 1YQJ1~1YQJ3 without a reset coil, and the I bus voltage switch with a reset coil Switching relays 1YQJ4~1YQJ7, and the normally closed contact of I mother isolating switch and resistor R1 connected in series, said resistor I is connected to the reset coil of I mother voltage switching relay 1YQJ4~1YQJ7 with reset coil, and the normally open contact of I mother isolating switch The common terminal of the normally closed contact of the isolating switch of the I mother is connected to the positive power supply; the normally open contact of the isolating switch of the II mother in series, the voltage indicator light of the II mother, the switching relay of the II mother voltage without a reset coil 2YQJ1~2YQJ3, and a reset coil The II bus voltage switching relays 2YQJ4-2YQJ7, and the series-connected II bus isolating switch normally closed contacts and resistor R2, the other end of the resistor R2 is connected to the reset coil of the II bus voltage switching relays 2YQJ4-2YQJ7 with a reset coil, The common terminal of the normally open contact of the Ⅱ mother isolating switch and the normally closed contact of the Ⅱ mother isolating switch is connected to the positive power supply, and the contact 1YQJ1 of the Ⅰ mother voltage switching relay and the Ⅱ mother are connected between the positive power supply of the signal and the simultaneous action input end of the switching relay. The series circuit formed by the voltage switching relay contact 2YQJ1 is characterized in that: the two ends of the series circuit are connected in parallel by another contact 1YQJ5 of the mother voltage switching relay with a reset coil and the second mother voltage switching relay contact 2YQJ5 with a reset coil. a series loop.