Research On Transmission Line Traveling Wave Fault Location Based On Wavelet Transform And The Permutation Entropy

Transmission lines act as the sole channel for transporting electrical energy, its safetyand stable operation will have a direct impact on the power supply reliability of the entirepower system. When the transmission line faults appear, to find out the fault location quicklyand accurately, to repair lines and restore power timely, can reduce economic losses causedby power outages, which has a very important significance to the safety and stable operationof the whole power system. The traveling wave fault location with its high reliability accuracyand fast positioning, and merits of being free from the system parameters, the fault resistance,the neutral grounding modes and line load, has become a research hot topic in recent years.This paper takes the transmission line as the research object, conducting a series of analysisand studies on the transmission line fault localization method, which is based on mathematicalmorphology, wavelet transform and the permutation entropy. The main work and researchresults, as follows:(1) Firstly, this paper comprehensively summarizes the current situation of moderntravelling wave fault location methods and research, and then, analyses the mechanism oftransmission line traveling wave, traveling wave propagation characteristics and commontraveling wave analysis tools. Finally, the principle, algorithm and application of wavelet andmorphology are discussed.(2) Study on the filtering effect of wavelet transform and mathematical morphology fordifferent noise in the transient traveling wave signal, according to the proposed de-noising, aintegrated de-noising algorithm that using mathematical morphology morphological structureof adaptive filter scale structural elements and wavelet soft threshold integrated de-noisingalgorithm is proposed to process the traveling wave signals. And the simulation experimentsprove that the proposed method can filter the noise effectively, providing a guarantee fortraveling wave fault signal processing.(3) The paper puts forward a transmission line fault location method based on acomprehensive de-noising method combined with wavelet transform modulus maxima. Firstly,fault current signal is de-noised by comprehensive de-noising method and then processed bythe Karrenbauer transform, and then the traveling wave line mode component is detected andanalyzed by wavelet transform modulus maxima and the morphological gradient transformmethod, the fault location method is determined by comparing different effects.(4) This paper propose a new traveling wave mutation detection method, which is basedon permutation entropy of the transmission line traveling wave fault location method. First ofall, take the mapping of typical nonlinear time series of Logistic containing mutation point and the sinusoidal noise signal as the object, to verify the validity of the signal detected bypermutation entropy. Then combined with comprehensive de-noising method, the singularityof traveling wave signal is detected. Finally, the results will be compared with the wavelettransform modulus maxima method and the morphological gradient transform method, toverify the feasibility of permutation entropy applied for the fault location of transmission line.