A precise measurement method for positive sequence parameters of EHV and UHV transmission lines and its application

A precise measurement method for positive sequence parameters of EHV and UHV AC transmission lines is proposed. The mathematical models are presented in detail. Global Positioning System (GPS) is used as the synchronous signal for the measurement carried out at different substations simultaneously. The measurement device and digital simulation results are given. Finally, the measurement results of two 500 kV AC transmission lines are given and compared with the measured results by traditional method. Results from both simulation and on-site measurement show that the proposed measurement method is feasible, and its measurement accuracy can satisfactorily meet the requirements of engineering measurement.