基于小波包变换的暂态电流保护在带固定串补的超高压线路上的应用研究

运用柏德生法则，定性地分析了带固定串补的超高压线路上的波过程及保护安装处反射电流与透射电流的S域表达式，该暂态量保护的性能不受串补电容金属氧化物变阻器（MOV）保护非线性特性的影响。以小波包分解作为分频手段对暂态电流进行分频，利用高低频段能量比作为保护判据。理论推导与仿真结果证明，该原理的保护可应用于带串补的超高压线路。且与串补电容安装位置基本无关，对不同的系统运行方式、故障类型、故障初始角及过渡电阻不敏感。

Research on application of wavelet packet transform based boundary protection on fixed series compensated EHV transmission lines

The transmission of fault-generated wave is discussed. The Peterson Principle is applied to deduce the equations of the reflective and transmissive currents in S domain on fixed series compensated EHV transmission lines.The performance of such transient protection(won't) be influenced by the non-liner characteristic of the metal oxide varistor(MOV) protection.The wavelet packet transform technique is employed to determine the energy ratio of a high frequency band to a low one.Theoretical deduction and simulation results show that the transient current protection can be applied to series compensated EHV lines.The performance of the protection won't be influenced by the location of series capacitor and isn't sensitive to different system operation patterns,fault types,fault inception angles and fault earth resistances.