Interturn starting method of shunt reactor

Abstract

The invention provides a turn-to-turn starting method of a shunt reactor. A problem to be solved is to improve sensitivity and reliability of a starting element. The method comprises steps as follows: calculating parameters by a microcomputer such as a secondary rated impedance of the main reactance, a theoretical value of secondary rated impedance of a smaller reactance, a three-phase voltage at the line side, a vector value of current and measured impedances of three phases in main reactance of the shunt reactor; determining that there is a turn-to-turn fault when any measured impedance of three phases in main reactance of the shunt reactor is not greater than 0.95 * the secondary rated impedance of the main reactance. Compared with the present technology, the invention greatly improves the sensitivity of starting provided that ensuring starting reliability of the turn-to-turn protection by using a characteristic that the measured impedance of the reactor is substantially constant when the reactor is normal, and the measured impedance thereof is obviously lowered when a turn-to-turn fault happens; when an external fault of reactor happens, the turn-to-turn protection starting element of the shunt reactor does not starts because the measured impedance is unchangeable, and that only starts for the turn-to-turn protection when an internal fault happens.

Description

technical field

[0001] The invention relates to a protection method of an electric power system, in particular to a method for judging the start-up of inter-turn short-circuit protection of a shunt reactor of an ultra-high voltage and ultra-high voltage main equipment of the electric power system. Background technique

[0002] Since there are many grounding faults in the power system line, the reclosing after the grounding fault, the transient current contains rich high-order harmonics in the process, and there is energy exchange between the reactor and the line-to-ground capacitance, so the harmonics of the shunt reactor Over-temperature and severe micro-vibration cause a relatively high ratio of turn-to-turn short-circuit faults. However, due to the inductive electrical characteristics of the single-winding inductive electrical characteristics of the current reactor turn-to-turn protection start-up element, the reliability and sensitivity of the start-up element have not be...

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