In case of slight inter-turn short circuit of shunt reactor

the circulating current of its short turn can reach ten times and even dozens of times of rated current

lead to insulation damage of insulation

but the variation of its phase voltage and current is very small and cannot be used as fault characteristic quantity of inter-turn protection. In this paper

the difference of the imbalance of terminal voltage and phase current of shunt reactor it taken as new fault characteristic quantity characterizing the inter-turn short circuit by way of mathematical models of shunt reactors which is earthed directly or through small reactance. The fault detection algorithm of inter-turn short circuit of shunt reactor is simulated and analyzed

the effectiveness of the algorithm is verified by the simulation result. The detection algorithm is the significant improvement of existing zero and negative sequence fault detection algorithm. The method does not need calculatingreactance

is simple and accurate in calculation.