Fault Diagnosis Research Of Compensation Capacitor And Tuning Area Of Jointless Track Circuit

As the key equipment for ground-train communication in Chinese train control system,jointless track circuit plays an important role in ensuring the safe operation of tiains and improving the driving dfficiency of trains.The compensation capacitor and the equipments in the tuning area will not only shorten the effective transmission distance of the signal,but also cause frequency crosstalk between adjacent segments,and even cause “red-light-strap” and “code-missing” to endanger the traffic safety.At present,there are problems such as incomplete diagnosis,high diagnositic cost and low efficiency in the fault diagnosis of jointless track circuit at home and abroad,which can no longer meet the needs of the rapid development of Chinese railway.Therefore,this thesis analyzes the influence characteristic of compensation capacitor and tuning area equipments fault on shunt current curve,and proposes the fault diagnosis method of jointless track circuit compensation capacitor and tuning area equipments.Firstly,four-terminal network models with the faultless of jointless track circuit,compensation capacitor failure and equipments failure in the tuning area are respectively established based on the transmission line theory and the two-port network theory.The expression of the shunt current curve is obtained.Set the simulation parameters,simulate and analyze various fault conditions,and obtain the influence law of different fault types on the shunt circuit curve.Then,a comprehensive fault diagnosis method for jointless track circuit based on fuzzy qualitative trend analysis is proposed.According to the characteristics of the shunt current curve,the shunt current curve is divided into several single-peak segments by the position of the compensation capacitor.If the single-peak segment is a complex single-peak segment,the single-peak segment extreme point is found and continues to be divided into two simple single-peak segments.The least-squares method is used to fit the divided single-peak segment,and the trend of the single-peak segment is extracted.And identifying,extracting the Knowledge of the shunt current curve trend of various fault conditions of the jointless track circuit,and calculating the matching degree between the actual signal and the classic failure mode in the knowledge base to obtain the diagnosis result.The results show that the method can accurately identify the fault type of a single tuning area equipment and two compensation capacitors at the same time,which makes up for the shortcomings of the current diagnostic methods in the compensation capacitor fault and the tuning area equipment fault.Finally,a comprehensive fault diagnosis method for jointless track circuits based on angle and linear eigenvectors is proposed.According to the characteristic of the change of the tangential angle of the shunt current curve at the position of the compensation capacitor fault,and the characteristic of the change of the linear trend of the shunt current curve closed to the top three compensation capacitor sections of the transmitting end when the tuning area equipments are faulty,the angle feature vectors and the linear trend are respectively extracted.The angle feature vectors are detected from the transmitting end in turn.If the detection result shows that the determining index of the angle feature vectors are smaller than the determining threshold,the faulty compensation capacitor is output.Otherwise,the linear trend is used to determine whether the tuning area equipments are faulty,and the diagnosis result is given.The results show that the method can accurately diagnose the fault type of single tuning area equipment and multiple compensation capacitors at the same time,which has higher diagnostic efficiency and wider diagnostic range than the diagnostic method of fuzzy qualitative trend analysis.