Protection method for turn-to-turn short circuit fault of controllable reactor

Abstract

The invention discloses a protection method for a turn-to-turn short-circuit fault of a controllable reactor. The protection method comprises the following steps of 1, acquiring the electrical quantity of the controllable reactor, namely the grid-side three-phase voltage, three-phase current and the control-side three-phase current; 2, calculating the control side zero-sequence current, the network side negative-sequence voltage and the negative-sequence current according to the electrical quantity; 3, taking the control side zero-sequence current as a protection starting threshold to carry out protection starting judgment; 4, calculating a negative sequence power direction angle by using the grid-side negative sequence voltage and the negative sequence current, and taking the negative sequence power direction angle as a judgment basis of a fault position; and 5, when a small turn-to-turn fault occurs, processing the negative sequence power direction angle by using a dynamic mean value method, and then judging the fault occurrence position in the system. According to the protection method, the control side zero sequence current and the grid side negative sequence power direction principle are combined, so that the sensitivity of the control side turn-to-turn short circuit protection of the controllable reactor can be improved; the problem of negative sequence power direction angle fluctuation during small turn-to-turn short circuit is solved by adopting a dynamic mean value method, and the protection reliability is improved.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a protection method for inter-turn short-circuit fault of a controllable reactor. Background technique [0002] The rapid development of the economy has led to an increase in electricity consumption. However, the power production center and the power load center are far away, and the nearby supply of electric energy cannot be realized, and a large-capacity, long-distance transmission system is required to transmit electric energy. With the continuous increase of transmission capacity, the existing ultra-high voltage transmission system has already faced the problem of insufficient transmission capacity. It is necessary to develop a UHV transmission system to solve such problems and form a grid layout with the UHV transmission system as the backbone grid. Solve the problem of uneven spatial distribution of electricity load, and truly ach...

AI Technical Summary

Problems solved by technology

[0005] The structure of the controllable reactor is relatively complex, and the failure rate is higher than that of other equipment with the same voltage level, especially the turn-to-turn fault of the controllable reactor body. It is a very common fault, and it is also difficult to detect. high

[0006] At present, the more common turn-to-turn fault protection methods of controllable reactors are generally differential protection based on the principle of magnetic balance and zero-sequence power direction protection. , it is difficult to detect faults, and the sensitivity is insufficient

Images