Research On Trip Time Of Improving Line Reclosing Success Rate

As an effective measure to ensure the safe power supply and stable operation of the power system,the automatic reclosing technology is widely used on EHV/UHV transmission lines.The problem of the secondary arc current generated by the single-phase reclosing and the overvoltage problem caused by the three-phase reclosing may cause the coincidence of the automatic reclosing failure.In order to improve the success rate of automatic reclosing,this paper proposes an optimization scheme for controlling the trip timing of circuit breaker based on phase-controlled switching technologyAiming at the problem of secondary arc current after single-phase reclosing circuit tripping,the equivalent model of transmission line is established.The influence of the initial state of each component on the transient current of the submerged supply current is studied.The results show that the free component of the submerged current is related to the trip timing of the faulty phase breaker.When the non-fault phase line voltage is 0,the breaking is completed,and the transient process of the submerged current can be suppressed to some extent.Based on this,a tripping time control scheme for improving the success rate of single-phase reclosing is proposed.The simulation model of the double-sided power system is established by PSCAD/EMTDC.The simulation results of various schemes are verified.The results show that the analysis conclusion is correct and the proposed method It has certain applicability in different fault locations,transition resistances,and tidal current deliveryFor the three-phase reclosing transmission line,the arc transient process and overvoltage phenomenon after tripping of the circuit breaker with different fault types are analyzed.A trip timing control scheme for improving the success rate of three-phase reclosing is proposed and verified by simulation.The simulation finds that when this scheme is adopted,the arc of the fault arc can be accelerated,and the condition of the overvoltage can be controlled within the standard range,and the impact on the arrester when the operating overvoltage occurs on the line can be reduced to a certain extent.