机械式直流断路器自适应重合闸策略

An Adaptive Reclosing Strategy for Mechanical DC Circuit Breaker

直流断路器的及时重合闸可降低瞬时性线路故障的不利影响,提高直流线路输电效率。然而,机械式直流断路器的直接重合闸可能会引入故障电流冲击或者引起线路电压振荡。为解决该问题,首先建立了机械式直流断路器重合闸期间的系统等值电路,然后分析了永久性故障和瞬时性故障时电容电压的暂态变化特征,利用电容电压增量的低通滤波值识别线路故障性质,从而提出了适用于机械式直流断路器的自适应重合闸策略,最后在PSCAD/EMTDC平台里验证了所提策略的有效性。分析与仿真结果表明,所提策略有效地抑制了重合闸于永久性故障时的故障电流冲击以及重合闸于瞬时性故障时的线路电压振荡。

Timely reclosing DC circuit breaker(DCB)can reduce the adverse effect of instantaneous faults and improve the transmission efficiency of DC lines.However,reclosing mechanical DCB may lead to a fault current impulse or line voltage oscillation.To solve this problem,the equivalent circuit of the system during reclosing the mechanical DCB is established,and the transient characteristics of the capacitor voltage during the permanent fault and the instantaneous fault are analyzed.Thereafter,the low-pass filter value of the capacitor voltage increment is used to identify the fault properties,and thus an adaptive reclosing strategy suitable for the mechanical DCB is proposed.Finally,the effectiveness of the proposed strategy is validated using PSCAD/EMTDC simulations.The analysis and simulation results show that the proposed strategy can effectively suppress the fault current impulse during the permanent fault and the line voltage oscillation during the transient fault.