Facts Devices And Their Effect On Power Transmission System

As the demand for electricity increases,the large-scale power system now faces many significant challenges,which include power fluctuations and oscillations due to power outages,blackouts,natural disturbances,and system failures along transmission lines,loads,and generators.In recent years,blackouts have occurred in many countries of the world.These major disturbances lead to instability in the power system and make it difficult for the system to operate,plan and maintain the schedule.Under these circumstances,the FACTS controllers such as Interline Power Flow Controller(IPFC),Static Synchronous Series Compensator(SSSC)and Unified Power Flow Controller(UPFC)can significantly improve the transient stability and thus improve the entire system stability during disturbances.In addition to the fast control of active and reactive power in the power system,the SSSC,IPFC,and UPFC devices also play an additional role in transient stability enhancement and therefore play a crucial role in system stability control.In this study,the specific performance and comparison performance of three kinds of devices are studied in terms of damping of the system oscillation.It further studied the relationship between voltage support and loss reduction characteristics and oscillation damping for each device,allowing the power system planner to incorporate the three devices’ transient stability,loss reduction,and voltage support characteristics.In this thesis,the UPFC,SSSC,and IPFC FACTS controllers were used for transient stability enhancement(TSE)analysis taking into the dynamic environment of the standard IEEE 14 bus test system by successfully implementing TSE single compensation device(SSSC)and double compensation device(UPFC and IPFC).The inherent characteristics of these three devices are inferred.By adding fast-acting and properly-positioned FACTS devices,corresponding time-domain responses with and without FACTS devices are obtained and analyzed.From the perspective of system oscillation damping,this study effectively reveals the specific comparison performance of the three devices.The results show that when FACTS devices are used,transient stability can be significantly improved by greatly reducing the post-fault stabilization time of the power system and effectively damping the network oscillation compared to the case where the FACTS devices are out of service.