JPH0381675A - Starting system for fault point locating device - Google Patents

Abstract

PURPOSE:To start a fault point locating device at one time irrespective of success or failure of extinction of arc by starting the device with an operation of a relay for ground fault and an AND condition elapsing a certain time from throw-in of a circuit breaker of resistor for neutral point grounding point. CONSTITUTION:The fault point locating device 11 is started with the operation of the relay 12 for ground fault over voltage and the AND circuit 14 closing an auxiliary contact 10 of the breaker 9 during a longer time than the set time of a timer 13. For the ground fault generated at the time when the breaker 9 is being closed, the fault locating device 11 is started. At this time, the breaker is closed by the operation of a protective relay, thereby the arc extinction grounding system is formed, and a zero-phase-sequence voltage is made unstable, then the fault locating device 11 is not started even if the operating and recovering of the relay for ground fault over voltage are repeated, since the auxiliary contact 10 of breaker 9 is closed. Further, when a time of timer is set so that a circuit for the auxiliary contact 10 of breaker 9 is not operated until the breaker 6 is interrupted even if the breaker 9 is closed and the arc extinction is failed, the device 11 is started at one time either the arc extinction is succeeded or failed at the time of ground fault for one line.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for activating a failure point locating device installed at an electric station (power station, substation) in order to locate a failure position in a power transmission line.

[Conventional technology]

A method for activating a fault point locating device in the event of a ground fault in a high-resistance grounding system transmission line is to use a ground fault overvoltage relay to detect the zero-sequence voltage that occurs due to a ground fault, and this activates the fault point locating device. ing.

[Problem B that the invention attempts to solve]

The neutral point of the transformer is grounded by a reactor, and a neutral point resistor is connected in parallel to the arc extinguishing reactor grounding system beam axle via a circuit breaker. If such a single-line ground fault occurs in the grounding system, the protective relay device operates to interrupt the neutral point resistance circuit, and the arc extinguishing reactor is used as the grounding system in the hope that the arc at the fault point will be extinguished. When the post-neutral point resistance circuit is turned on, if the arc is successfully extinguished, the protective relay device becomes inoperable and power transmission can continue without the need to open the circuit breaker of the transmission line where the ground fault occurred. . However, if the arc is not successfully extinguished even with an arc extinguishing reactor grounding system, when the neutral point resistor circuit is turned on, the protective relay device operates and interrupts the transmission line where the ground fault has occurred. Open the vessel. When the system uses an arc-extinguishing reactor grounding system, the zero-sequence voltage fluctuates unstablely during the arc-extinguishing process, and may rise and fall around the operating setting value of the ground fault overvoltage relay. The relay will repeatedly operate and return. If the fault point locating device is activated by the operation of the ground fault overvoltage relay, there will be an inconvenience that the fault point locating device will be activated a plurality of times due to - number of failures.

[Means to solve the problem]

In order to prevent the failure point locating device from being activated multiple times due to a single failure, the present invention is designed to operate the earth fault overvoltage relay and turn on the neutral point grounding resistor circuit breaker after a certain period of time has elapsed. The failure point locating device is activated based on the AND condition.

[For use]

By doing this, the failure point locating device for the arc extinguishing reactor grounding system that uses a neutral point earthing resistor can detect a one-wire ground fault, whether the arc extinguishing is successful or the arc extinguishing is unsuccessful.
It can be started once.

【Example】

Figure 1 is a single-line circuit diagram of a fault point locating device that uses bus voltage and transmission line current to locate fault points at an electrical station with an arc-extinguishing reactor grounding system that uses a neutral point grounding resistor. This is the case of the startup method. In addition, FIG. 2 is a circuit diagram for implementing the "starting method" according to the present invention. In FIG. 1, 1 is a transformer, 2 is a reactor for neutral point grounding, and 3 is a resistor for neutral point grounding. , 4 is a busbar, 5 is a transmission line, 6 is a circuit breaker for the transmission line, 7 is a current transformer for obtaining the current of the transmission line, 8 is a transformer for obtaining the voltage of the busbar, 9 is a neutral point grounding 10 is an auxiliary contact of the circuit breaker that moves in the same way as the circuit breaker; 11 is a fault point locating device or its terminal device for locating the fault point of the power transmission line. When a single line ground fault occurs in the system, the circuit breaker 9 is opened for a certain period of time by the protective relay device, and the system becomes an arc extinguishing reactor grounding system. A ground fault overvoltage relay 12 (
Conventionally, the failure point locating device 11 was activated by the operation of this ground fault overvoltage relay 12, but in the present invention, as shown in FIG.
The failure point locating device 11 is activated by the AND circuit 14 of the operation of the circuit breaker 9 and the fact that the auxiliary contact 10 of the circuit breaker 9 has been closed for a time longer than the set time of the timer 13. Note that the set time of the timer 13 is set to be longer than the time from when the circuit breaker 9 closes to when the power transmission line circuit breaker 6 opens in the event of an arc extinguishing failure. By doing this, the failure point locating device 11 is activated in the event of a ground fault that occurs while the circuit breaker 9 is closed. Due to the operation of the protective relay device, the circuit breaker 9 is opened and the arc-extinguishing reactor is grounded, and the zero-sequence voltage becomes unstable and fluctuates around the operating setting value of the ground fault overvoltage relay, causing the ground fault overvoltage relay to operate. Even if the reset is repeated, the failure point locating device 11 does not start because the auxiliary contact 10 of the circuit breaker 9 is open. Furthermore, even if the circuit breaker 9 closes and the arc fails to extinguish, the circuit of the auxiliary contact 10 of the circuit breaker 9 is set by a timer so that it will not operate until the circuit breaker 6 of the transmission line is disconnected by the operation of the protective relay device. If so, the fault point locating device 11 will not be activated, and therefore, the fault point locating device 11 will be activated once regardless of whether arc extinguishing is successful due to a - line ground fault or not.

【Effect of the invention】

By activating the failure point locating device on the AND condition of the operation of the earth fault overvoltage relay and the fact that a certain period of time has elapsed since the circuit breaker for the neutral point grounding resistor was turned on, arc extinguishing can be prevented even if arc extinguishing is successful. It can be activated once even if the

[Brief explanation of drawings]

FIG. 1 is a single-line circuit diagram of a failure point locating device to which the starting method of the present invention is applied, and FIG. 2 is a circuit diagram for implementing the starting method according to the present invention. Code explanation

Claims (1)

[Claims] In a fault point locating device used for grounded power transmission lines that uses a combination of resistance grounding and arc-extinguishing reactor grounding for the transformer neutral point, the operation of a ground fault overvoltage relay that operates at zero-sequence voltage and the transformer neutral point resistance A starting method for a fault point locating device characterized by starting the fault point locating device under an AND condition that a grounding circuit breaker is turned on and a certain period of time has elapsed.