Research On Fault Location Of High Voltage Transmission Line Based On VMD

High-voltage transmission lines are the main carrier of electric energy transmission across regions and long distances.Their operating environment is complex and changeable,and various faults are prone to occur during operation,which seriously threatens the safety of the power grid and has a significant impact on social and economic benefits.Locating and resolving faults quickly and accurately to ensure safe and stable grid operation is a major challenge for the power sector.At this stage,the scale of the power grid continues to develop,and T-type transmission lines have become more widely used in power grid construction applications.Therefore,this paper investigates the fault location problem for double-ended systems and T-shaped lines by using variational modal decomposition(VMD)to decompose the fault traveling wave combined with the Teager energy operator(TEO)to determine the location of the fault point by analyzing the first spike in the energy curve.First,this paper researches and analyzes the traveling wave theory of transmission lines,describes the generation and propagation process of transient traveling waves,and selects the double-end ranging method to realize the calculation of fault distance.To address the problem that the empirical modal decomposition(EMD)is prone to modal aliasing in the decomposition,which leads to the inability to characterize the original signal variation trend and subtle local features,the principle of VMD is further proposed and analyzed,and by comparing the decomposition of simulated faulted noisy signals with EMD and VMD respectively,it is found that the VMD algorithm can better complete the decomposition of non-stationary signals and weaken the modal aliasing and endpoint effects.Secondly,the IMF component with the highest frequency is selected as the characteristic signal component of the fault transient in the mode of the fault current decomposed by VMD,and the Teager energy operator,which can detect the sudden energy change,is introduced,and the first spike in the energy curve is the moment when the initial traveling wave of the fault reaches the measurement end.The first spike in the energy curve is the moment when the initial traveling wave reaches the measurement end.Then,using the new algorithm to avoid the problems of wire draping and uncertainty of wave speed in the fault location of the double-end ranging algorithm and improve the ranging accuracy.Finally,using the PSCAD software to build the simulation model of the double-ended system and the T-shaped line,and using the Matlab software to process the fault data obtained under different working conditions.For the double-ended system,different fault types and transition resistances are set respectively,and compared with the traditional wavelet transform ranging method.The simulation results show that the VMD-TEO-based ranging method has a high accuracy in the dual-ended system.The time difference between the initial traveling waves arriving at the three ends of different branches at the fault point is used to determine the fault branch of the T-line,after that the fault distance is further calculated.The simulation results verify that the method can distinguish the branch of the fault well and realize the precise location of the fault point,which has some applications.Figure[36]Table[5]Reference[76]...