基于小波暂态能量的超高压输电线路保护新方法  

A New Protection Approach for EHV Transmission Lines Based on Wavelet Transient Energy

作　　者：蒋洪涛[1] 黄纯[1] 杨帅雄[1] 

机构地区：[1]湖南大学电气与信息工程学院,湖南省长沙市410082

出　　处：《电网技术》2012年第8期248-253,共6页Power System Technology

基　　金：国家863高技术基金项目(2010AA0522555001);湖南省科技重大专项(2009FJ1014);湖南省自然科学基金项目(10JJ5055)~~

摘　　要：提出一种基于故障信号高频分量小波暂态能量的保护新方法。首先对线路两端的电流信号进行离散小波多尺度分解,获取特定频段的小波细节系数;然后计算线路两端的小波细节系数的差值与平均值,并计算它们在移动时间窗内的能量,分别作为保护的动作量和制动量,构成暂态能量差动保护判据。所提方法对线路区内故障具有高灵敏性和高速动性,对区外故障具有高可靠性,同时不受故障类型、故障位置、过渡电阻、故障时间、初始相位、系统振荡等故障条件的影响。Matlab/Simulink仿真验证了所提出方法的可行性和实用性,能够满足EHV输电线对保护的要求。A new protection approach based on wavelet transient energy of fault signal＇s high-frequency component was proposed. Firstly, for current signals from both terminals of the transmission line the multi-scale decomposition of discrete wavelet was performed to attain wavelet detail coefficients of a specific frequency band; then the differences and average values of wavelet detail coefficients at both terminals of the transmission line were computed and their energy within a sliding time window was calculated, and the calculated energy were respectively taken as the operating quantity and the restraining one of the protection to construct criteria of transient energy differential protection. The proposed protection approach was indicative of high sensitivity and excellent high response speed for faults occurred inside protection zone as well as high reliability for faults occurred outside protection zone, besides, it was not affected by fault types, fault position, transition resistance, the moment when fault occurred, the phase angle by which the fault occurred and power oscillation of power system. The proposed approach could meet the requirement of EHV transmission lines to protection, and both feasibility and practicality of the proposed approach were verified by results of simulation based on Matlab/Simulink.

关 键 词：输电线路 继电保护 暂态能量 离散小波变换 细节系数 

分 类 号：TM773[电气工程—电力系统及自动化]