ABSTRACT
This chapter discusses reactive power compensation, mainly in transmission systems installed at substations. Reactive power is either generated or consumed in almost every component of the system, generation, transmission, and distribution and eventually by the loads. Reactive power compensation in a power system is of two types—shunt and series. Since most loads are inductive and consume lagging reactive power, the compensation required is usually supplied by leading reactive power. Shunt compensation of reactive power can be employed either at load level, substation level, or at transmission level. Static VAR compensators, commonly known as Static VAR compensators, are shunt-connected devices, vary the reactive power output by controlling or switching the reactive impedance components by means of power electronics. Power injection on the shunt and series connections increases the flexibility and the number of modes of operation of the Unified power flow controller.
