Research On Fault Location Method Of Transmission Line Based On Wavelet Transform

With the increasing development of society,the improvement of the national economy is inseparable from the power sector's secure and reliable power transmission to users.Nowadays,the scale of power systems is expanding,voltage levels are constantly increasing,distances between transmission lines are increasing,and power grid structures are becoming more complex.As the key link of the power system,the transmission line bears the important responsibility of the power system's stable transmission of electrical energy.Because of the greater influence of external factors,transmission lines are more prone to failure than other links in the power system.The fast and accurate fault location method can accurately find the location of the fault point at the first time,which not only greatly reduces the burden of hunting,but also speeds up power recovery,reduces economic losses caused by power outages,and improves the stability and stability of power systems.Economical.Therefore,the vigorous development and widespread application of transmission line fault location technology is of great significance to the safety and stability and economic operation of power systems.First,this article introduces the basic concepts of traveling waves,analyzes the basic laws of traveling waves in transmission lines,and proposes the use of Karen Bell transform matrix to eliminate the coupling effect between three-phase transmission lines.Several fault ranging methods are briefly introduced,and the main advantages and disadvantages of the existing ranging methods are compared and analyzed.Secondly,the basic concepts of wavelet transform are briefly introduced in this paper.From the perspective of multi-resolution analysis,the fault traveling wave signal is wavelet-decomposed,and the time when the traveling wave head first reaches each measurement point is determined according to the wavelet transform modulus maximum value theory.Thirdly,through the study of existing ranging methods and the application of wavelet transform technology,a new method for traveling-wave fault location of single-ended,double-ended,and T-type transmission lines that is not affected by wave speed is proposed.It performs phase-analog transformation and wavelet transformation on the fault traveling wave component,and measures the time when the traveling wave head first reaches the measurement point to complete fault ranging,eliminating the influence of wave speed uncertainty on ranging accuracy.Finally,according to the aforementioned method,a simulation model of transmission line is built in Matlab/Simulink environment for simulation verification.A large number of simulation experimental results show that the proposed method is not affected by factors such as transition resistance,fault type,traveling wave speed,etc.The error is small,with high accuracy and good applicability.Figure[35]Table[9]reference[80].