Radiated emissions from FACTS equipment operational within substations-part III

Transient electromagnetic (EM) emissions are generated when thyristor or gate turn-off thyristor (GTO) valves are being switched on and off within substations installed with static var compensators (SVCs) and static synchronous compensators (STATCOMs). These emissions may cause malfunction of, or damage to, electronic equipment positioned nearby without appropriate protection. Four SVC-based substations and one STATCOM-based substation were selected for electromagnetic-interference (EMI) measurement, analysis, and evaluation. A comparison was made between the radiated EMI features from each. The analyzed results were correlated to the present electromagnetic-compatibility standards, and recommendations of changes for immunity tests were presented specifically for flexible ac transmission system (FACTS)-based radiated EMI. Preliminary analysis was also given to the causes of FACTS-based EMI, which indicated that valve switching behavior and the stray parameters of FACTS equipment layout were the main contributors to high-frequency-radiated interference.