Analysis of Control Technique for STATCOM

Modern electric power system is facing many challenges due to day by day increasing complexity in their operation and structure. In the recent past, one of the problems that got wide attention is the power system instability. To solve the problem of transient stability in the late 1980s, the Electric Power Research Institute (EPRI) introduced a new approach to solve the problem of designing and operating power systems; the proposed concept is known as Flexible AC Transmission Systems (FACTS).STATCOM is new FACTS devices used to solve voltage instability.This paper proposes the use of 9 level Cascaded Multilevel Inverter (CMLI) as a STATCOM to improve the performance of transmission line.In this paper we have taken only single machine connected to a bus.In order to reduce the THD selective harmonic elimination technique is proposed.