Inter-turn short circuit is a common fault of reactor in operation. In view of the insufficient maintenance state of reactor

a kind of on-line monitoring method which is suitable for inter-turn short circuit fault of distribution reactor is proposed in this paper. First

the equivalent circuit model of the reactor is set up to obtain calculation method of electrical parameters of the reactor. Then

a set of on-line monitoring system of short circuit fault is set up. Finally

the study of short-circuit test of reactor under different fault position and fault degree is carried out. The study results show that the variation rate of equivalent reactance and resistance of inter-turn short circuit of reactor has the symmetry of short circuit position

the absolute value of the variation rate in the middle is maximum and in both ends is minimum. With the deepening of short circuit fault

the equivalent reactance shows the trend of decrease and the decreased amplitude increases. The equivalent resistance shows the trend of increase and the increased amplitude increases. The study technology can achieve effective monitoring of inter-turn short circuit fault of distribution reactor.