Equipment Fault Diagnosis for Electrical Separation Joint of Jointless Track Circuits Using Qualitative Trend Analysis
Sun Shangpen · Zhongguo tiedao kexue · 2014
The induced voltage amplitude envelope of cab signal was simulated according to the calculation model of a jointless track circuit based on uniform transmission line theory.The influence laws of such factors as the equipment faults of electrical separation joints,the faults of trimming capacitors,the variations of ballast resistance and train running speed,etc.on the induced voltage amplitude envelope curve of cab signal were investigated.With the induced voltage amplitude envelope curve of cab signal between the transmitter and the third trimming capacitor as the analysis object,a fault diagnosis approach for the electrical separation joint based on qualitative trend analysis theory was proposed.Signal trend information was extracted using interval-halving algorithm,and then trend matching algorithm was adopted to calculate the similarity between an actual signal trend and that under each fault mode in the knowledge base of diagnosis rules.Finally,fault diagnosis was done through comparing similarity values.Simulation experiment results show that the incipient faults of the electrical separation joint are well detected using this approach.The correct rate of fault diagnosis can reach 94.4% when SNR is 50dB,and it has higher adaptability to the variations of ballast resistance.