Voltage Support by Distributed Static VAr Systems (SVS)

Abstract

This paper shows that when load centers require Static VAR Systems (SVS) for regulated voltage control, the strategy of using many, small, distributed SVS located at distribution buses is more advantageous than a few large bulk SVS located at the transmission or sub-transmission bus. The advantages are (i) standby to meet N-1 reliability criterion is reduced; (ii) costly high voltage transformers are no longer needed because the SVS can be connected directly to the low voltage distribution buses; (iii) distribution-side voltage support is more effective so that the total MVAr requirement of the distributed SVS is less. Simulation studies have demonstrated that the distributed SVS units operate harmoniously together.