Effective Application of Static Var Compensators to Damp Oscillations

Static Var Compensator (SVC) is recognized to be effective to improve transient stability and to damp voltage fluctuation. The reason why power system planners hesitate to apply SVC to their systems is because of its expense. The authors have proposed a combination type SVC, which consists of both thyristor controlled capacitors and reactors and mechanically switched capacitors. This combination makes it economical to apply SVC to improve transient stability. In this paper another proposal is concerned with the conceivable installation of SVC to damp oscillations of power systems. The so-called "Reset Filters" is applied to the voltage detective circuit of SVC. Because of its leading characteristic, it produces a damping effect on the power system. The economy and effectiveness of the combination type SVC equipped with Reset Filter is illustrated to improve stability of the power system both analytically and quantitatively.