Investigation of small signal dynamic performance of IPFC and UPFC devices embedded in AC networks

Abstract

This thesis proposes the small signal model for the Interline Power Flow Controller (IPFC). Using this model, the damping performance of the IPFC with different power system configuration is investigated and also compared with the AC Transmission System (FACTS) based controllers such as the Unified Power Flow Controller (UPFC). The IPFC and the UPFC in constant power control mode can be viewed as effectively cutting the connected transmission line. This change on the structure of the network results in a significant change on the small signal stability. This thesis also addresses issues regarding the different levels of models that are required for the investigation of the behavior of FACTS. An effective validation approach that uses a minimum sized demonstration platform is proposed. This platform is small enough for detailed EMTP validation, yet large enough to exhibit the range of transient electrical and electromechanical behavior which is the focus for FACTS devices. To demonstrate the approach, the small signal models of the system embedded with the IPFC and the UPFC are developed respectively. The results obtained from small signal analysis are validated with EMTP-type simulation and show a close agreement.