过渡电阻对距离保护的影响及其对策分析

Analysis of the Influence of Transition Resistance on Distance Protection and Its Countermeasures

110kV线路多采用距离保护作为线路主保护,而短路点过渡电阻的存在使阻抗继电器的测量阻抗发生变化,易造成距离保护拒动。针对过渡电阻对距离保护的影响问题,基于PSCAD仿真平台搭建110kV双侧电源输电线路及线路距离保护的仿真模型,分析在不同短路情况下保护的动作特性,并基于此线路对仿真结果进行测试验证。仿真结果表明,过渡电阻对距离保护会产生较大影响,而零序电流保护元件抗过渡电阻干扰的能力较强,作为110kV线路的后备保护,与距离保护配合具有较高的可靠性,能维持系统的稳定性。

In 110 kV lines,distance protection is mostly used as the main protection of the line.The presence of a transition resistance changes the measurement impedance of the impedance relay,which causes the distance protection to refuse to move.Aiming at the problem of the influence of the transition resistance on the distance protection,the PSCAD software was used to establish a 110 kV double-sided power transmission line.The operating characteristics of the relay protection under different short-circuit conditions were analyzed.The simulation results were tested and verified based on this line.The distance protection has a greater impact,and the zero-sequence current protection element can remove the fault caused by the transition resistance and maintain the stability of the system.