Influence of Three-phase Reclosing on Distance Protection
In order to improve the reliability and security of power supply,a new reclosing method of fault distance,system reactance and trigger angle is proposed to solve the problem of unsatisfactory reclosing of three-phase reclosing in AC-DC power system.According to AC-DC system model when the three-phase fault occurs on the transmission line of the AC system,the distance protection expression is deduced in the head and the end coincide,and the influence of the rectifier side and inverter side system reactance,critical fault distance on the protection is analyzed.Considering control mode and the DC system has commutation failure,analysis of the variation trend with fire angle and fault voltage variation is done.It is concluded that the optimal coincidence scheme of the distance protection maloperation risk in AC-DC system is reduced.The correctness of the conclusion and effectiveness are verified by simulation of the Southern Power Grid and AC-DC system.The results show that the new reclosing scheme can effectively reduce the risk of distance protection and improve the safety and stability of power system.
three-phase reclosingdistance protectionmaloperationAC-DC system
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