Transmission voltage support using distributed static compensation

Abstract

FACTS devices such as static var compensators (SVC) or static compensators (STATCOM) are often examined in transmission planning studies and applied in transmission systems for reactive power control and voltage support. For some transmission applications and also for smaller utilities that need to deal with voltage issues at the distribution system level, a distributed approach to reactive power control and voltage support with STATCOM systems in multiple locations where voltage and reactive issues exist can be more effective than a centralized solution. This STATCOM system design is called Distributed Static Compensation. This distributed approach also achieves higher reliability with the redundancy, which eliminates the operational risk of the total loss of reactive power support in the area in the event of a large centralized unit being out of service. The Distributed STATCOM system has a high short-time rating. This unique short-time rating can be applied to support voltage recovery during significant dynamic events. This paper presents and discusses two real system case studies on application of Distributed STATCOMs for voltage support in North American transmission systems. Modeling aspects of the Distributed STATCOM systems are also discussed.