Modeling of STATCOM and SVC for Power System Steady State Operation and Enhancement of Transient Stability of a Multi Machine Power System by STATCOM

Abstract

Transmission networks of modern power systems are becoming increasingly stressed because of growing demand and restrictions on building new lines. One of the consequences of such a stressed system is the threat of losing stability following a disturbance. Flexible ac transmission system (FACTS) devices are found to be every effective in stressing a transmission network for better utilization of its existing facilities without sacrificing the desired stability margin. Flexible AC Transmission System (FACTS) controllers, such as Static Synchronous Compensator (STATCOM) and Static VAR Compensator (SVC), employ the latest technology of power electronic switching devices in electric power transmission systems to control voltage
and power flow, and play an important role as a stability aid for and transient disturbances in an interconnected power systems.
This report presents the improvement of transient stability of a multi-machine power system with a STATCOM. Transient stability improvement is essential from the view point of
maintaining system security that is the incidence of a fault should not lead to tripping of generating unit due to loss of synchronism. Static synchronous compensator is widely used in power system to control power by injecting appropriate reactive power into the system. STATCOM has the capability of improving stability and dampin by dynamically controlling it’s reactive power output. The STATCOM is modeled by a voltage source connected to the system through a coupling transformer. The transient stability improvement of the multi-machine power system at different fault ondition is investigated in this work.