基于形态学的HVDC线路故障识别与定位方法研究

有效的故障行波波头辨识及测距方法是行波保护应用的重要环节。在介绍数学形态学原理及算法的基础上,通过对故障暂态电压行波的多分辨形态学梯度MMG(Multi-resolution Morpho-logical Gradient)处理,提取出故障折、反射行波的幅值及极性,以此对高压直流输电HVDC(High Voltage DC transmission)线路故障类型进行识别,并利用单端或双端测距算法进行故障测距。同时,讨论了几种与线路故障暂态相似的故障类型:换相失败和逆变侧单相接地故障。Matlab仿真结果表明,所提保护算法能够很好地区别HVDC线路故障和其他相似的暂态过程,也能准确地进行故障定位。

HVDC transmission system fault identification and locating algorithm using mathematical morphology

Effective fault traveling wavefront identification and fault locating method is the basis of traveling wave protection.The principle and algorithm of mathematical morphology are introduced,based on which the amplitude and polarity of the refractive and reflected transient traveling waves are abstracted by transient fault voltage traveling wave treatment using MMG(Multi-resolution Mor-phological Gradient) method and the HVDC(High Voltage DC transmission) line faults identified and located using single and double ending fault locating methods.Some types of HVDC faults similar to line fault transient are discussed,such as commutation failure and AC single-phase grounding fault near inverter station.Simulations with Matlab show that the proposed criterion and algorithm work well in distinguishing HVDC line fault and some other similar faults,and correct locating the fault position.