Abstract:The secondary resonance elimination devices are widely adopted in distribution network, but some field application effects are not satisfactory, and there are some cases of resonance elimination failure. In this paper, based on the analysis of voltage and flux variation characteristics of PT resonance in distribution network, a new control method of resonance elimination is proposed, which is to launch a device when zero sequence flux passes through zero point.This method avoides the influence of PT non-linear characteristics on the secondary resonance elimination process, consumes the resonant energy rapidly, and makes the network return to normal quickly. For the problem that the zero sequence flux cannot be measured in actual system, a zero-crossing detection method based on zero sequence voltage is proposed. The simulation results show that compared with the conventional resonance elimination method, the proposed method can effectively improve the success rate of the secondary resonance elimination, greatly reduce the working time of the secondary resonance elimination devices, and reduce the influence on the distribution network.