Study on Inter-Turn Short Circuit Fault of Dry-Type Air-Core Shunt Reactor Under Low Voltage with Low Frequency

Abstract

When the inter-turn short circuit fault occurs in the dry-type air-core shunt reactor (DASR), the short circuit loop will consume a large amount of active power, which will cause the equipment temperature to rise in a short time and damage the equipment. Therefore, it is very important to detect the fault in the early stage of the inter-turn short circuit fault. This paper presents a method to detect the number of inter-turn short circuit fault turns of the DASR based on modified active power (P <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> ) and modified reactive power (Q <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> ), at low voltage with low frequency. The formulas for Pm and Q <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> are obtained by adding correction factors to the formulas for active power and reactive power respectively. Their correction factors are obtained by using genetic algorithm. The variations of Pm and Q <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> under normal condition and short circuit condition with different turns are studied. The inter-turn short circuit fault with different frequency and different fault location is simulated. It provides a feasible method for detecting the inter-turn short circuit fault of the DASR and determining the number of short circuit turns.