Development And Application Of On-line Insulation Monitoring System For High Voltage Apparatus In Substation

Has been the maintenance of high voltage electrical equipmentpursuant to electrical equipment preventive testing procedures for regularpreventive tests and scheduled maintenance in case of power failure.Preventive tests need to be carried out under conditions of the deviceblackout, concentration of test time, heavy workload, regular maintenancehas certain blindness; can not be found running the equipment inside thehidden faults in a timely manner, can not ensure the safe operation ofequipment maintenance cycle; their test efficiency is poor, the test voltageis much lower than the operating voltage of the device, resulting in someof the equipment insulation defects can not be effectively detected.Substation high voltage capacitor type device is a current transformer(CT), voltage transformers (PT), coupling capacitors the arrester themand collectively referred to occupy a large proportion of the small of thesubstation, the substation high voltage equipment.Based on analysis of all major domestic and international dielectric lossangle measurement method, the paper analyzed the traditional harmonicanalysis in measuring the characteristics and fence effect "and" spectralleakage resulting dielectric loss in the reference capacitor type devicefactor detection technology based on a windowing function algorithmimproved analysis, better able to reduce spectral leakage and picket fenceeffect, and the algorithm for the simulation analysis. Take into accountthe impact of environmental factors as well as the circuit itself mayintroduce interference, the reference phase technology, research and useof "zero flux current transformer and capacitive device DSP-basedinsulation online monitoring in place of measurement units so Thedielectric loss angle accuracy improved to meet the project needs.The main work and research results are as follows: 1: research and the use of the FFT algorithm based on the Hanningwindow, and the design of the MATLAB simulation program to verifycapacitive high-voltage equipment insulation parameters2: research and utilization of a novel zero-flux current sensor improve thesignal sampling accuracy3: Design a reference phase capacitive device insulation in situmonitoring of the unit, to solve the problem of the decline inlong-distance signal transmission may result in errors and the accuracy ofthe measurement resultsIn this paper, the design of Nanhui220kV substation electricalequipment insulation monitoring system for capacitive high-voltageequipment dielectric loss monitoring is effective, relative value methodand trend method can achieve reliable equipment insulating state aftersystem commissioning, the measured data analysis monitoring, provides asolid foundation for the realization of the equipment condition-basedmaintenance management.