Application benefits of Line- or self-commutated Static Var Compensator

The power grid development in recent years shows that the transmission system increases its complexity due to such aspects as increasing contribution of renewable energy sources and the change of top-down energy flow to bidirectional flow. This has an impact on the voltage stability and necessitates system voltage support. Line commutated Static Var Compensators (SVC) as well as self-commutated Static Var Compensators provide means to achieve system voltage control in affected system nodes. The proper selection of the technology applied to accomplish this task depends on the power grid conditions. This paper presents a comparison of self- and line-commutated SVC technologies. The proper selection of the technology based on an exemplary SVC design is also shown.