Impact of Time Duration on Energy Injected during the Test to Verify Repetitive Charge Transfer Rating

Surge arresters prevents the failure of power system equipment during high voltage transients. These transients can be switching, lightning, steep current impulse etc. The latest edition of IEC 60099-4 has introduced the test to verify repetitive charge transfer rating, in order to evaluate the charge carrying capability of surge arrester varistor blocks during the event of high energy surges. Station class varistor blocks can be tested using rectangular impulses or unipolar sine half-wave impulses of 2ms to 4ms virtual total duration. In this paper, we analyse the impact of time duration on energy injected during the test to verify repetitive charge transfer rating. Study is performed on Station Low (SL), Station Medium (SM) and Station High (SH) designation blocks using rectangular impulse wave shape for various time duration between 2ms to 4ms and its impact on the energy injected through the block is quantified and analyzed.