距离保护承受过渡电阻能力分析

探讨系统各因素对单端电源双回线路负荷侧纵联距离保护承受过渡电阻能力的影响。对一起220 kV系统单端电源双回线路负荷侧纵联距离保护拒动事件进行分析,并以数值化的方式分析线路互感等因素对负荷侧距离元件承受过渡电阻能力的影响。线路互感、有源侧零序阻抗、无源侧零序阻抗的变化均不会对负荷侧纵联距离元件承受最大过渡电阻能力产生明显影响,有源侧运行方式是影响负荷侧纵联距离元件承受最大过渡电阻能力的主要因素。该结论可为优化纵联距离保护的整定计算提供依据。

Analysis of Transition Resistance Bearing Capability of Distance Protection

Factors in the power system which influence the transition resistance bearing capability of load side pilot distance protection with single-terminal power source and double-circuit transmission lines are discussed. A maloperation event of a load side pilot distance protection with single-terminal power source and double-circuit transmission lines in 220 kV system are analyzed. The influence of factors such as the mutual impedance of transmission lines to the transition resistance bearing capability of load side distance elements are analyzed numerically. The changes of the mutual impedance of transmission lines, zero-sequence impedance of source side and zero-sequence impedance of passive side have no obvious influences to the transition resistance bearing capability of load side pilot distance elements. The operation mode on source side is the main factor that influences the transition resistance bearing capability of load side pilot distance elements. The conclusion can provide evidence to the optimization of the setting calculation of pilot distance protection.