Research Of Matrix Fault Location Algorithm For Distribution Network Based On Current Innovation

Distribution network directly bear the power supply of the terminal load,its working conditions directly affect the user's power supply reliability.According to the voltage level and the actual grid parameters,distribution network grounding methods can be divided into effective grounding and non-effective grounding two categories.Fault characteristics of different systems under different fault conditions are obvious.Meanwhile the existing distribution network fault location algorithm is poor at generality and fault tolerance.In this paper,based on the advantages of the innovation theory in the identification of bad data,load mutation,topology error and other abnormalities in the grid,the improved distribution network matrix location algorithm is proposed.The research achievements are as follows:Firstly,this paper analyzed the current innovation characteristics of different grounding mode systems under different fault conditions.Based on the symmetric component method and the innovation theory on injection source.The current expression before and after the fault is obtained.The current state estimation value before the fault is used as the forecast value,the current measurement value after the fault is taken as the measured value.Measured value minus forecast value to generate the current innovation.The characteristics of current innovation under different conditions is analyzed.Secondly,the fault line location and the bad data identification problem is solved.Using current innovation,according to the formation method of the distribution current innovation graph,link branches is added at related nodes.The load injection current as well as the power injection current in multi terminal power distribution network are introduced as the link branch innovation.The innovation graph features of line fault and measurement bad data is deduced.The problem of identification between these two situations can be solved by applying the theory of current innovation graph.Thirdly,the improved matrix location algorithm is proposed.In order to improve the traditional matrix location algorithm,the current innovation after filtering bad data is used as the information source,instead of the traditional(0,1,-1)overcurrent modes.The fault line can be located in two ways,one is the innovation mutation path,one is the fixed and adaptive threshold criterion.The matrix location algorithm can be used in the location of different line fault types.Finally,this paper built 33 nodes distribution network model and verified the positioning algorithm.Using simulation and data analysis function in MATLAB software,the corresponding distribution network system model is established to verify the reliability of the localization algorithm under different system faults.