Research On On-line Monitoring And Fault Location Of MV Cable Based On Bi-terminal Synchronous Sampling

Rated voltages of urban distribution grid are mainly 10kV or 35kV. With the development of city construction, overhead lines are gradually replaced with underground cables. Despite of lower failure rate, cables are difficult for fault location, which influences the reliability and security.Enhancing automation, service quality and management of distribution grid is also crucial, so fault monitoring and location promptly are worthy of in-depth research. This paper conducts the research on fault location of distribution grid, based on bi-terminal synchronous sampling.Considering the difference between MV cables and OHTL, a more applicable and accurate fault location method was put forward with theoretical technical research.Functions of cable length to voltage and current values of two terminals are deduced. Using the function approximation ability of ANN, ANN model was established to undergo training with voltage and current values of two terminals, which simulates the relationship between cable length and voltage and current values of two terminals. Iteration was made to lacate fault spot by ANN model. PSB (Power System Block Set) of MATLAB was chosen to simulate normal and fault circumstance. Feasibility of algorithm was testified by simulation analysis.By comparison with other communication methods, F29DM was chosen as communication model, and has undergone long distance wireless test, which accumulated experience for further application. Hardware framework and circuit were established also.