Measurement of electromagnetic emissions from FACTS equipment operational within substations - part I

Within substations installed with flexible ac transmission systems (FACTS) equipment [such as static var compensator (SVC) or static synchronous compensators (STATCOMs)], transient electromagnetic emissions are generated during the switching of thyristor valves. These emissions may cause malfunction or damage to electronic equipment positioned nearby if appropriate immunity measures are not taken. An electromagnetic-compatibility measurement system was devised, and four SVC substations and one STATCOM substation were selected for electromagnetic-interference (EMI) measurement, analysis, and evaluation. The aim of the research project was to characterize both the conducted and radiated emissions produced by FACTS equipment. The probable impact of emissions from FACTS equipment is discussed. The measurement system used is described together with the measurement methodology. A simple circuit analysis was also carried out on the causes of FACTS-based EMI to provide some insight into the interference mechanism.