电力电子化背景下交流电网保护配置方案

Research on AC Protection Scheme Under the Background of Power Electronics

大量电力电子器件的应用使得交流系统的故障特性发生了较大变化,现有保护配置方案面临严峻挑战。首先分析了纯交流系统、直流输电系统、新能源并网等不同场景下交流线路故障暂态电流波形特征,进而利用相关系数进行暂态电流波形辨识,构建了新型保护原理与配置方案。最后,分析了新型保护方案对互感器、采样频率、数据窗长的配置要求。新型保护配置方案普适性强,出口速度快,实现简单。基于EMTDC/PSCAD仿真与样机测试结果验证了分析结论的正确性。

The application of a lot of power electronic equipment has caused a large change in the fault characteristics of the AC system,and the existing protection schemes faces greater challenge.This paper firstly analyzes the waveform characteristics of AC line fault current in different fault scenarios,such as pure AC systems,DC transmission systems and new energy grid-connection,and then a new protection scheme based on identification of transient current spectrum is proposed.At last,the effect of current transformer,sampling frequency and data window length is analyzed.The new protection scheme has many application scenarios,fast operation,and simple implementation.The conclusions are verified by the simulation results of EMTDC/PSCAD and prototype test.