Research On Fault Location System Of Distribution Line Based On Phase Method

In order to guarantee the normal of the industrial production and people's life,when the distribution network fault,people of power system should be timely find out the cause of the problem and determine the fault point location,they also repair to troubleshooting in the first place.For helping maintenance crews find fault grounded point fast,we could adopt the method of distribution network based on phase of single-phase earth fault positioning way online.When malfunction occurs,the phase of zero sequence current in the around fault point location will reverse,and use this design for information collection in one side of line end.Including three phase current acquisition phase and three phase current value calculation,the current numerical superposition is the zero sequence current.And use the wireless transmission way to transmit data to the operator,at the operator to determine the specific fault point location.Phase method is often used on fault location and the positioning of the way.Discriminant method in this paper,by comparing a variety of advantages and disadvantages,and finally determine the phase method is adopted,by the use of Matlab software Simulink module structures,transmission lines.And the possible fault types in the circuit simulation,get each fault of three-phase voltage,current and zero sequence current waveform,we could clearly see that failure occurs after the zero sequence current reverse phase,further verify the discriminant method of zero sequence current phase can be applied to the fault point location.According to the feasibility of the method,this paper designed the current collection and single chip microcomputer data processing storage systems.Including current acquisition module,signal processing module,GPS module,wireless transceiver module and MCU software design.This design adopts the current mutual inductance coil to realize the collection of three phase current information,after collecting signal through shaping filter in the signal processing module,including thefilter circuit,amplifying circuit and microprocessor;Then with the help of single chip microcomputer internal 10 AD converter to realize analog signals to digital signals,and through the design of single chip microcomputer program integrating data processing.Finally the wireless transmission data remote transmission of information to complete the current work,and deal with in the station to transmit information to determine specific line fault point location.In this paper,the distribution network fault location system for testing,include each module separate test and zero sequence current acquisition terminal of overall test,specific test results are given to verify the reliability of distribution network fault location system,in real-time acquisition fault point before and after the two three-phase current limiting IA,IB,IC and I0 zero sequence current,collect altogether two groups before and after the point of failure data,the data is processed to get two points of zero sequence current phase diagram and the comparison between the two one,the around fault point of zero sequence current amplitude increase obviously,and the phase difference for roughly 180°.Determine simulation of the distribution circuit fault point between the patch A and patch B,and in this paper,theoretical basis,which verified the accuracy of the fault point positioning system.