Investigations on the performance of voltage source inverter based facts controllers

Abstract

The progress of a nation is assessed by its economic growth, industrial development besides technological advancements. The per capita consumption of electrical energy is treated as a measure to evaluate the overall progress. It is imperative that the existing resources are fully utilized before venturing to look for alternatives, in the present energy crisis scenario. However, it is equally important to realize the rapid depletion of energy sources and contemplate measures to augment its sustainability. The field of power electronics has witnessed tremendous development in recent times. The advent of new power controlled devices has contributed significantly to an enhanced performance of the existing power converters. The birth of innovative converter topologies has paved the way for further improving the overall power quality. It has contributed to build sophisticated utilities and enable precise control of flow of power over the transmission lines. The transmission network has expanded considerably stretching over long distances with a view to reach the dictated requirements through the available power sources. The use of static var compensators (SVC) at strategic points in the network has served to regulate the ac system voltages. The stability limit of the power system is generally raised by offering series capacitor compensation using thyristor controlled switched capacitor (TCSC). These ac power electronic controllers, namely static var compensator and thyristor controlled series capacitor have emerged under the generic name of flexible ac transmission system (FACTS) controllers. The ability of the switching devices with secure turn on and off capabilities has led to the construction of voltage source inverters (VSI). This switched power converters have now become a constituent part of FACTS controller and includes in its fold categories namely static synchronous compensator (STATCOM) and static synchronous series compensator (SSSC), which when connected back to back with a common dc link brings out.