Research On Selective Leakage Protection Based On Wide Area Information

Coal occupies the main position in our country's energy,and many of the mines in our country use the cable power supply.The cable is easy to be damaged in the underground environment,the damage of the cable is likely to cause the leakage accident,which affects the progress and efficiency of the underground work.When the leakage fault occurred in underground coal mine,in order to quickly locate the fault zone,avoid tripping,according to the principle of partition structure of wide area protection,the underground power supply system,this paper proposes a new method of selective leakage protection based on wide area information under the.According to the characteristics of mine power system,combined with the partitioning scheme of wide area protection,regional division of the installation position in mine power supply line according to the switch,zero sequence information by zero sequence transformer installed on the feeding switch in each divided area.With zero sequence voltage judgement as to whether there is a fault line basis,based on the difference of the zero sequence current of adjacent regions as features,and the features in the fault line and non fault line phase and amplitude difference as a criterion,comparing the current characteristics of different regional zero sequence wide area information,finally obtains the fault point area.Taking into account the underground zero sequence current information is vulnerable to interference,this paper adopt a fault signal based on empirical mode decomposition(Empirical Mode,Decomposition,EMD)filtering scheme,the fault signal is decomposed into several components,which were part of the signal component of the re combination of new signals after noise reduction.In order to explore the feasibility of the method,this paper takes the actual mine area power supply system as reference model,and uses MATLAB Simulink to build the simulation model.The fault criterion is verified by simulation,and the influence of transition resistance on the simulation waveform is also considered.Simulation results show that Matlab,the method proposed in this thesis can not only determine the fault line,but also can get the fault area,help to improve the efficiency of underground maintenance,has a strong practical value.