Study Of Insulator Leakage Current Online Monitoring System Of Overhead Line Based On GPRS

With the rapid developing of national economy, the voltage class of the power system in our country is continuously increased, and the bad influence of the contamination flashover gets more and more serious. Laboratory studies and industrial experience have shown that the variation of insulators leakage current has close relationship with insulators contamination, which provides an integrated reflection of the contamination flashover, so the insulator leakage current online monitoring system is an effective method to estimate the contamination degree and initial failure of insulators. Existing insulator leakage current online monitoring system has sorts of disadvantage such as inconvenience of mounting, shortage of leakage current measurement range, fallibility of data transmission and difficulty of diagnosis of contamination condition on insulator surface. In this paper, the key technologies of insulator leakage current online monitoring system are researched and a new type of leakage current remote online monitoring system based on GPRS is developed.The insulator leakage current online monitoring system introduced in this paper real-timely monitors the contamination condition of insulators surface by directly measuring leakage current, dada sampling, data-processing and data communication with monitoring center. With the help of the device, an active partial aperiodic cleaning method will substitute the passive traditional periodic general cleaning method in order to reduce workload and prevent the contamination flashover to a larger extent.Non-contact leakage current transducer is adopted in this system and provides a mounting way without change original insulator-tower structure. Application of new transducer adapter circuit lead to improvement of performance and solution of deficiency in precision, narrow band and sensitivity of change in magnetic core parameter of traditional rogowski coil based current transducer. Programmable variable gain amplifier adopted in the signal processing circuit largely extend the leakage current measurement range and provide a solution to amplify the large range leakage current. The GPRS communication technology is applied in the remote data transmission, which improves the data transfer rate, accurate and reliability of the system and can provide a accurately real-timely data transmission of all the field monitoring data. The solar electrical energy supply system is used in this system, which not only assure a reliable power supply to system, but also avoid the potential insulation puncture dangerous of...