On-Line Monitoring of Lightning Surge Intruding Into Substation by Current Response of Busbar Capacitor Voltage Transformer
Hongbin Wang · Power System Technology · 2011
The basic principle of on-line monitoring of lightning surge intruding into substations of 110 kV and above voltage classes as well as the calculation of equivalent parameters of resistance,inductance and capacitance in the loop circuit of capacitor voltage transformer(CVT) under high-frequency are presented.The influences of calculation errors of equivalent parameters on overvoltage monitoring are analyzed by simulation model.An approach for on-line monitoring of lightning surge intruding into substation by current response of CVT is proposed to remedy the defects in existing monitoring methods.Based on the proposed method,a busbar overvoltage monitoring system based on current in busbar CVT circuit of substation,by which can monitor busbar overvoltage and intruding currents via inlets can be monitored,is developed to implement the automation,intelligentization and informatization of monitoring and statistics of failures occurred in substation.Comparison of actually measured waveforms and results of simulation by alternative transient program(ATP) shows that the proposed monitoring system can operate continuously and effectively.