JPH07112331B2 - Transmission line protection relay device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transmission line protection relay device that protects a transmission line of a power system from a near point failure.

[Conventional technology]

FIG. 5 is, for example, a block configuration diagram showing a conventional transmission line protection relay device described in “Protective Relay System” on pages 64-68 of Densho Shoin, February 25, 1974. PS is the power supply of the power system, L is the protected transmission line, F is the near point fault, CT is the current transformer, PT is the voltage transformer of the protected transmission line L, _If is the fault current, and E is the voltage transformer PT. Secondary voltage of 52
It is a circuit breaker. In addition, 1 is a distance relay (hereinafter simply referred to as distance relay), which has a phase characteristic of the Moh characteristic as shown in FIG. 6. The Moh characteristic distance relay is a kind of directional relay with voltage suppression and is essentially It has the characteristic that it has directionality and few unnecessary movements.

FIG. 7 is a time chart for explaining the operation of the transmission line protection relay device shown in FIG.

In the time chart of FIG. 7, typical values are used for the operation time and the recovery time of the distance relay 1 and the circuit breaker 52.

Next, the operation will be described.

(A) When the near-point fault F occurs during operation of the protected transmission line L (see FIG. 7 (a)) First, the input fault voltage of the distance relay 1 is as shown in FIG.
It is set to a value smaller than the static operation limit voltage of the distance relay 1 as shown by E _f , for example, about 0.1V.

Since the distance relay 1 has a memory function of storing a sound voltage before a failure occurs, when a near-point failure F occurs, the voltage change associated with the failure is sensed by the secondary voltage E of the voltage transformer PT to operate. . The distance relay 1 that has detected the close-point failure F operates, for example, in 40 ms, but at the same time outputs a trip command to the breaker 52 to open the breaker 52 and remove the close-point failure F.

(B) When the protected transmission line L in which the near point fault F has occurred is turned on by the circuit breaker 52 (see FIG. 7 (b)), the grounding disconnector of the protected transmission line L remains closed, that is, The state of changes in the input fault voltage E _f and the fault current I _f when the circuit breaker 52 is turned on while the near-point fault F is occurring
It is shown in Figure (b). The input fault voltage E _f of the distance relay 1 is about 0.1 V as in the case of FIG. 7 (a).

However, in this case, since the memory function of the distance relay 1 does not operate, the distance relay 1 cannot operate, and therefore the close-point failure F cannot be eliminated.

[Problems to be solved by the invention]

Since the conventional transmission line protection relay device is configured as described above, it is possible to detect and eliminate a near-point fault during operation, but it is possible to detect a near-point fault due to forgetting to operate the ground disconnector, etc. When the power transmission line is turned on, the failure cannot be removed, and another backup protection relay (not shown) will be used to rescue the immediate trip. Not only will the damage to the protected transmission line be significantly expanded, but the system stability will be secured. There was a problem that it could not be done.

The present invention has been made to solve the above problems, and even when the circuit breaker of the protected transmission line is turned on while the near-point fault has occurred, the circuit breaker trips at high speed. The purpose of the present invention is to obtain a highly reliable transmission line protection relay device capable of removing a failure.

[Means for solving problems]

A transmission line protection relay device according to the present invention includes a distance relay capable of switching a phase characteristic from a mode characteristic to an offset mode characteristic by an external input signal, and a switch which operates prior to or almost simultaneously with the operation of a circuit breaker. A pulse circuit that generates a pulse output only for a certain period of time after the operation of the switch is provided, and the distance relay is controlled by the output signal of the pulse circuit.

[Work]

The distance relay of the transmission line protection relay according to the present invention has a moo characteristic for a malfunction during operation, and operates by a memory function, but when the breaker is turned on, it operates with an offset moo characteristic for a certain period of time thereafter. Even if the circuit breaker of the protected transmission line is turned on in the state where the near-point fault has occurred, the distance relay is surely operated at a high speed to trip the circuit breaker.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same parts as those in FIG. 5 are shown with the same reference numerals. In FIG. 1, 52A is an auxiliary contact of the circuit breaker 52 which is closed when the circuit breaker 52 is closed, and 3 is the auxiliary contact 52A which is closed. After that, a pulse circuit that generates a pulse output of 100 ms, for example, operates with a moo characteristic when there is no output signal from the pulse circuit 3, and operates as an offset moo characteristic when there is an output signal from the pulse circuit 3. It is a relay.

Next, the operation of the transmission line protection relay device according to the present invention will be described below with reference to the time chart of FIG.

(A) When the near-point fault F occurs during operation of the protected transmission line L (see FIG. 2 (a)) The operation in this case is exactly the same as the operation of the conventional transmission line protection relay device. That is, when the near-point fault F occurs, the phase characteristic of the distance relay 2 operates through the mho characteristic, the distance relay 2 operates at high speed by the memory function, and the circuit breaker 52
The trip command is output to. Then, the circuit breaker 52 is opened, and the near point fault F is removed.

(B) When the protected transmission line L in which the near-point fault F has occurred is turned on by the breaker 52 (see FIG. 2 (b)) In this case, when the breaker 52 is turned on, the auxiliary contact is made at the same time. 52A is closed and pulse output is generated from the pulse circuit 3 for about 100ms, and the phase characteristic of the distance relay 2 is switched to the offset mode characteristic only during this time. Ensures high speed operation and trips circuit breaker 52 to eliminate faults.

In addition, in the above-mentioned embodiment, the example in which the breaker 52 is closed and the auxiliary contact 52A is closed at the same time as the closing timing of the breaker 52 is described, but as shown in FIG. Even if the contact 3-52A of the switch 3-52 is used, the same effect as that of the above-described embodiment can be obtained.

Further, as shown in FIG. 4, even when the output of the reclosing relay 4 automatically turns on the circuit breaker 52, the circuit configuration is such that the output of the reclosing relay 4 drives the pulse circuit 3. Even if a permanent failure has occurred at the closest point, it is possible to reliably re-cut at a high speed after the breaker 52 is automatically turned on.

〔The invention's effect〕

As described above, according to the present invention, the circuit is configured so that the phase characteristic of the distance relay is set to the offset mode characteristic only for a fixed time after the circuit breaker is turned on, so that the transmission line in which the near point fault has occurred is turned on. Even in this case, the distance relay operates reliably at a high speed, the damage to the protected transmission line can be minimized, and the stability of the system can be secured at the same time.

[Brief description of drawings]

FIG. 1 is a block diagram of a transmission line protection relay device according to an embodiment of the present invention, FIG. 2 is a time chart for explaining the operation of FIG. 1, and FIGS. 3 and 4 are other embodiments. Block configuration diagram, FIG. 5 is a block configuration diagram of a conventional transmission line protection relay device, FIG. 6 is a phase characteristic diagram of the distance relay of FIG. 5,
FIG. 7 is a time chart explaining FIG. 52 is a circuit breaker, 52A is an auxiliary contact of the circuit breaker, L is a protected transmission line, CT is a current transformer, PT is a voltage transformer, 2 is a distance relay, 3 is a pulse circuit, 3-52 is an operation switch, 4 Is a reclosing relay. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] 1. When a near-point failure occurs on a protected transmission line,
In a transmission line protection relay device that operates a circuit breaker by detecting a fault current and a fault voltage of the protected transmission line to remove the near-point fault, the transmission line protection relay device is provided on a bus side of the protected transmission line, and A current transformer connected to one end of the circuit breaker, a voltage transformer provided on the transmission line side of the protected transmission line and connected to the other end of the circuit breaker, the current transformer and the voltage transformer A single distance relay connected to the relay, a switch that operates prior to or approximately at the same time as the operation of the circuit breaker, and an output is generated for a certain period of time after the operation of the switch to generate a phase characteristic of the distance relay. A transmission line protection relay device, comprising: a pulse circuit for controlling a characteristic to an offset mode characteristic. 2. The transmission line protection relay device according to claim 1, wherein the switch is a circuit breaker auxiliary contact that operates according to closing of a main contact of the circuit breaker. 3. The transmission line protection relay device according to claim 1, wherein the switch is an operation switch that closes the circuit breaker when operated. 4. The transmission line protection relay device according to claim 1, wherein the switch is a reclosing relay that automatically closes the circuit breaker.