Testing Technology on Very Fast Transient Overvoltage in 500kV HGIS Intelligent Substation

The very fast transient overvoltage (VFTO) generated during switching of disconnector in HGIS or GIS may affect the safe and stable operation of electric equipment, especially with large-scale application of electronic equipment in intelligent substation, the impact will be more serious. The test system and method of external VFTO and TEV on HGIS is comprehensive introduced in this paper. It is texted in 500kV substation that is the first completely intelligent substation. With compared the test results, the waveform characters and frequency components of the whole process of VFTO were proposed and the effects of VFTO to intelligent equipment were analysis. The ability of the main electric equipment to withstand VFTO is checked. The measured data can explore phenomena and laws of VFTO on intelligent substation, provided the basis to the insulation coordination of intelligent equipment and give a reference for the subsequent construction projects of intelligent substation.