基于故障分量的有功功率极性比较式纵联保护

根据故障附加网络中有功功率的极性特征,提出了基于故障分量的有功功率极性比较式纵联保护原理。其主要思想是:发生内部故障时,附加网络中线路两端有功功率的极性相同;外部故障时两端有功功率的极性相反;正、反向出口处故障时不存在死区问题。借助PSCAD/EMTDC电磁暂态仿真软件,搭建500 k V输电线路模型,对所提方案的动作性能进行了仿真和验证。在此基础上,进一步对比分析了分相保护方案和三相保护方案,并提出了基于故障分量有功功率幅值特征的选相方法。理论分析和仿真结果表明,所提方案能够正确判别区内、外不同类型的故障,抗过渡电阻能力较强,出口故障无死区,两端数据无需严格同步,且不受无功因素影响。

Active power polarity comparison pilot protection based on fault components

According to the polarity characteristic of active power in fault additional networks, an active power polarity comparison pilot protection principle based on fault components is proposed. The main idea of the proposed principle is that the active power at both ends of fault additional network has same polarities under internal faults and opposite polarities under external faults, and there is no dead zone under forward and backward outlet faults. With the help of PSCAD/EMTDC electromagnetic simulation software, a model of 500 kV transmission lines is built for the simulation and verification of operating performance of the proposed scheme, based on which, the split-phase protection scheme and the three-phase protection scheme are compared and analyzed, and a fault phase selection method based on the active power amplitude characteristic of fault components is proposed. Theoretical analysis and simulative results show that the proposed scheme can correctly identify internal and external faults, and immune to reactive power factor, it has great capability against transition resistance with no dead zone under outlet fault and do not need strict synchronization.