Design Of An On-line Monitoring System Of Polluted Electrified Railway Insulators

The electrified railway undertakes nearly80%of domestic logistics in raliway. Electrified railway insulator is one of the key components to ensure safe and stable operation of the tractive power supply system. Thus ensuring reliable operation of the insulator is extremely important. Most electrified railway insulator accidents stem from pollution flashover caused by insulator contamination. Railway operators invest a lot of manpower and resources to carry out regular maintenance of insulators every year. The overhaul is full of blindness, high costs, but also causes man-made damages to insulators and risks to normal operation of insulators, reducing the efficiency and reliability. To solve these problems, the paper designs an on-line monitoring system of polluted electrified railway insulators. This way of design can dynamically reflect the filthy conditions of insulators, provide an important basis for insulator pollution flashover warning, overcome the blindness of the regular maintenance and improve the safety and reliability of the tractive power supply system, through the electrified railway insulators on-line monitoring and comprehensive diagnostic analysis.In the analysis of the electrified railway insulators contamination mechanism and pollution flashover principle, this paper identifies the important parameters which meet on-line monitoring’s need, including power frequency leakage current effective value and high frequency discharge pulse number. The on-line monitoring device of polluted insulators is used as a baseline for the system and the insulators monitoring master station is used for estimating the filthy conditions. In view of monitoring device of leakage current, the center of on-line monitoring device of polluted insulators, the design is based on a chip selection in accordance with features of the monitoring, and it contains a collection of functional circuits of the leakage current acquisition unit, power supply circuit, filter circuit, amplifier circuit, RMS conversion circuit, pulse counting unit, central control circuit and peripheral circuit and communication circuit. This on-line monitoring system has the characteristics of real-time multi-tasking, full-featured, easy management and so on.This paper tests the performances of the active leakage current sensor and monitoring device of leakage current. The test results show that it can calculate the leakage current quickly and accurately. Insulators monitoring master station will be able to quickly and securely collect the data to storage and show the data curve, making operation more convenient and intuitive, through putting on-line monitoring system into operation.