电网技术
電網技術
전망기술
POWER SYSTEM TECHNOLOGY
2012年
1期
258-264
,共7页
林圣%何正友%陈鉴%李小鹏%钱清泉
林聖%何正友%陳鑒%李小鵬%錢清泉
림골%하정우%진감%리소붕%전청천
时频特征%行波%故障测距%Lipschitz指数%小波变换
時頻特徵%行波%故障測距%Lipschitz指數%小波變換
시빈특정%행파%고장측거%Lipschitz지수%소파변환
time-frequency characteristics%traveling wave%fault location%Lipschitz exponent%wavelet transform
行波波速度的确定及故障行波波头到达时刻的标定是影响行波测距精度的主要因素。在考虑线路参数频变特性对行波传播特性的影响的基础上,提出基于行波时频特征的单端测距方法:利用行波信号的利普希茨(Lipschitz)指数将行波信号的时频特性联系起来,运用最小二乘法拟合检测到的第2个行波波头的Lipschitz指数,并据此确定故障行波的频率成分及其到达时刻,计算故障距离。EMTDC仿真实验结果表明:所提方法测距精度较传统的行波测距方法有较明显的提高,且不受故障距离、故障电阻、故障初相角和故障类型的影响,能很好地适应完全换位和非完全换位线路。
行波波速度的確定及故障行波波頭到達時刻的標定是影響行波測距精度的主要因素。在攷慮線路參數頻變特性對行波傳播特性的影響的基礎上,提齣基于行波時頻特徵的單耑測距方法:利用行波信號的利普希茨(Lipschitz)指數將行波信號的時頻特性聯繫起來,運用最小二乘法擬閤檢測到的第2箇行波波頭的Lipschitz指數,併據此確定故障行波的頻率成分及其到達時刻,計算故障距離。EMTDC倣真實驗結果錶明:所提方法測距精度較傳統的行波測距方法有較明顯的提高,且不受故障距離、故障電阻、故障初相角和故障類型的影響,能很好地適應完全換位和非完全換位線路。
행파파속도적학정급고장행파파두도체시각적표정시영향행파측거정도적주요인소。재고필선로삼수빈변특성대행파전파특성적영향적기출상,제출기우행파시빈특정적단단측거방법:이용행파신호적리보희자(Lipschitz)지수장행파신호적시빈특성련계기래,운용최소이승법의합검측도적제2개행파파두적Lipschitz지수,병거차학정고장행파적빈솔성분급기도체시각,계산고장거리。EMTDC방진실험결과표명:소제방법측거정도교전통적행파측거방법유교명현적제고,차불수고장거리、고장전조、고장초상각화고장류형적영향,능흔호지괄응완전환위화비완전환위선로。
accuracy of determination There are two main factors influencing the traveling wave fault location, namely the of traveling wave velocity and the demarcation of the time when the wavefront of fault traveling wave arrives. On the basis of considering the impact of frequency-varying feature of parameters of transmission line on propagation characteristic of traveling wave, a single-terminal fault location method based on the time-frequency characteristics of traveling wave is proposed: firstly, the time characteristic of traveling wave's wavefront is linked with its frequency characteristic by Lipschits exponent of traveling wave signal; then by use of least squares method the Lipschits exponent of the detected second wavefront of traveling wave is fitted; finally, according to fitting result, the frequency components of fault traveling wave and the time when it arrives are determined, thus the fault distance can be calculated. Simulation results of EMTDC show that using the proposed fault location method, the accuracy of fault location is evidently higher than that by traditional traveling wave fault location methods, a~d the locatio~ accuracy is not affected by fault distance, fault resistance, fault inception angle and fault type, besides, the proposed method can well adapt to both transposed and untransposed lines.