Research On Power Cable Fault Location System Based On LabVIEW

In modern power system,power cable has been widely used because of its security and reliability.But the more widely used power cable,the higher the requirement of its reliability.However,during operation of the power system,due to some unavoidable interference factors,the performance of the power cable is degraded and damaged.In serious cases,cable power system failure and power supply system interruption will be caused.Therefore,in order to ensure the reliable operation of power cable,it is necessary to quickly locate the cable fault and remove the cable fault.Power cable fault location technology is particularly important.Traveling wave method is widely used in power cable fault location.In order to solve the problems of low identification of test waveform,large measurement error and long cable fault time caused by interference of various factors in the process of cable fault location,based on the understanding of the characteristics of power cable fault,the wavelet analysis of the current waveform when the fault occurs,multi-scale analysis of the fault signal,and detection of the singular value of the singular signal Through the analysis of the modulus maxima of the line mode current,the time difference between the first two wave heads is obtained,and then the corresponding fault distance formula is selected to calculate the fault distance.Finally,an example is given to verify the effectiveness of the method.Then,the power system computer aided design(PSCAD)is used to model and simulate several typical cable faults.Through PSCAD simulation under different conditions and variable parameters,the factors such as different neutral point operation mode,fault initial angle and transition resistance are analyzed.The results show that the traveling wave method has high accuracy in cable fault location,which is not affected by various factors.The effectiveness of traveling wave method is verified.Further,the cable fault location system based on Lab VIEW is designed in this paper.The overall design of the virtual instrument based on the data acquisition card,general PC and Lab VIEW is made.At the hardware level,the USB data acquisition card used by the system is mainly studied.At the software level,the cable type and wave speed selection,and wavelet signals are focused.The program design of Lab VIEW for denoising processing and modulus maximum search is studied.Finally,through the cable fault location system of Lab VIEW,the effectiveness of the system is verified by PSCAD simulation data and field test data.