The State Estimation Of The Secondary Equipment Of Digital Traction Substaion

Digital traction substation shoulders the important responsibility of supplying power to traction loads.Today,the research on state estimation of the primary equipment is quite mature,but for the secondary equipment,there hasn't been a unified evaluation criteria and diagnostic process.As the secondary equipment is getting more intelligent,its self-checking message and on-line monitoring information have been perfected,which provides data base to the research on state estimation and fault diagnosis.In order to make a reliable and comprehensive health assessment on the secondary equipment,this paper works on the technology of state estimation of the secondary equipment of traction substation.Firstly,analyses the on-line monitoring information source of the secondary equipment,then considering the certain fault is mostly caused by the hardware failure,eatablishes a complete state estimation index system for every equipment from the CPU module,power module,communication module and input/output module according to the newest monitoring information standard.Then,an improved fuzzy algorithm modle combining variable weight theory with membership degree correction is proposed to do the state estimation work.Based on the trational fuzzy comprehensive evaluation,considering that the constant weight may bring deviation in multi-level complex problem,and this algorithm modle can't react accurately to the index of rapid deterioration,this paper proposes a method using variable weight and membership degree correction to ameliorate,which improves the reliability and accuracy of the evaluation results.After getting the result of the equipment state estimation,accoding to the connection between health value and failure rate of equipment,a fixed parameter failure rate model based on the health value of the equipment is set up using inversion method.This real-time failure rate of the model is output along with the state estimation result,which can be a reference to the next step of fault prediction,fault diagnosis and residual life prediction.Lastly,with the help of the Matlab software platform and the Access database,completes a state estimation system of the secondary equipment which integrates graphical display,state estimation,intelligent alarm and data query function.This paper starts form the hardware level to assess if the equipment can function as specified,to reduce the incidence of the certain failure.Finally establishes a complete evaluation system of the secondary equipment,and uses the improved fuzzy comprehensive evaluation to improve the reasonableness of the evaluation results.Then combining the failure rate model,it completes a state estimation system of the secondary equipment,whichprovides a reliable and convenient evaluation system to operation and maintenance staffs.