Line drop compensation, high side voltage control, secondary voltage control-why not control a generator like a static VAr compensator?

Generators typically regulate terminal voltage via automatic voltage regulator and exciter equipment. The desired high side (transmission side) voltage schedule is usually maintained by the power plant operator or by slow SCADA-type process control computers. Power system dynamic performance, however, can be improved by faster regulation of the transmission voltage. Contrasted to generators, static VAr compensators are designed specifically for transmission voltage regulation. The transmission voltage is directly regulated at high speed. Total SVC and medium voltage component reactive power ratings are referred to the transmission side. All medium voltage equipment are designed to support the transmission side reactive power and voltage regulation requirements. The droop (slope) setting is usually small compared to generators regulating terminal voltage. This paper introduces the panel session on secondary voltage control. The author outline various methods for tighter high side voltage control, with emphasis on control of hydro generation in the US Pacific Northwest