At present, the power system plays a vital role in China's national economy, therefore, power indicator problem of the system attracting much attention, reactive power and voltage as one of the light elements give enough weight, the stability of the system is not to be neglected, static synchronous compensator (STATCOM) is a member that has high precision control, fast response time, dynamic reactive compensation ability in flexible exchange transmission system devices. At the same time, it has become a hot topic in the study of reactive power compensation devices and a growing number of widely applied to power system.