基于光学电流互感器的全波形母线保护研究

Research on Full Waveform Bus Protection Based on the Optical Current Transformer

母线是输配电网络的重要组成部分,起着汇聚和分配电能的作用。由于电磁式电流互感器存在不能准确测量非周期分量和磁饱和等问题,母线保护动作时间较长,有时甚至存在误动。为了提升保护动作性能,提出了一种利用全波形信息的母线保护新判据。新判据利用光学电流互感器采集而来的故障全波形数据,取1/4周期内的采样点进行判断,极大地减少了动作时间且不受磁饱和影响。进行了保护定值整定分析,在Simulink平台上搭建母线系统模型,仿真验证了新型母线保护动作时间较传统保护明显减少,且动作可靠性也有提升。最后,分析了谐波对新判据的影响,确保了判据的可行性。

Bus,an important part of the power transmission and distribution network,plays the role of convergence and distribution of electric energy.As the electromagnetic current transformer cannot measure non-periodic components accurately and has the problem of magnetic saturation,bus protection operation takes a long time,and false operation sometimes happens.A new bus protection criterion using full waveform information was proposed to improve the performance of protection actions.According to the new criterion,judgment was made at the sampling points within 1/4 cycle on the basis of fault full-waveform data collected by the optical current transformer,so that the operation time was reduced to a minimum under no affection of magnetic saturation.Setting analysis was made on the protection fixed value.A bus system model was established on the Simulink platform.Simulation verified that the protection operation time of the new type of bus was significantly reduced as compared with traditional protection,and operation reliability was also improved.Finally,the influence of harmonics on the new criterion was analyzed to ensure the feasibility of the criterion.