三相不对称输电线路单相自适应重合闸的研究

针对某些情况下故障性质判别灵敏度不足的问题,提出了三相不对称输电线路单相自适应重合闸故障性质判别方法。建立了三相不对称输电线路等效电路,推导了断开相恢复电压的计算公式,分析了不同故障性质情况下影响恢复电压幅值大小的因素。研究表明恢复电压幅值受故障性质、潮流方向和大小、故障相别及故障位置的影响。据此提出了新的故障性质判别方法,不同情况下采用相应的判别门槛值。EMTP仿真结果验证了该方法的正确性和有效性,能够提高重合闸成功率。

Study on single-phase adaptive reclosure of the asymmetrical three-phase transmission lines

According to insufficient sensitivity of distinguishing permanent faults from transient faults in some cases, a distinguishing method of single-phase adaptive reclosure for the asymmetrical three-phase transmission lines is proposed. The equivalent circuit of the asymmetrical three-phase transmission lines is established, and the calculation formula of recovery voltage of fault phase is derived, and the factors of influencing recovery voltage amplitude are analyzed under permanent faults or transient faults. The results show that the recovery voltage amplitude is affected by transient faults or permanent faults, the direction and size of the power flow, the fault phase and the fault location. So the new method which uses corresponding threshold in different conditions is proposed. The EMTP simulation results verify the correctness and effectiveness of the proposed method and it can improve the success rate of reclosing. This work is supported by Natural Science Basic Research Plan of Shaanxi Province (No. 2014JM7293) and Natural Science Research Plan of Education Department of Shanxi Province (No. 15JK1513).