Abstract:
This thesis deals with the design and construction of lightning surge voltage measuring system in high voltage 230 kV lines. The measuring system composes of damped-capacitor voltage-divider, surge detector and surge recorder. The characteristics of voltage divider were carried out in accordance with international standard including impulse withstand test, ac withstand test, partial discharge test, step response test, short term stability test, linearity test and scale factor was determined. The measuring system was used to measure and record the lightning impulse in laboratory, the recorded waveforms were illustrated. The test result showed that the measuring system works properly. The measuring system was installed in 230 kV transmission line at EGAT's substation, Bang-Plee