Var dispatch and voltage control with feasible setting to controllable shunt compensators

Traditionally, voltage control capability of the SVCs is described by PV bus model with full capacity available. In this paper, based on the sensitivity model for var dispatch and voltage control for SVCs, contributing factors, e.g. the available control margin, slope, reference voltage, static voltage characteristic of the power system, are studied. The numerical results show that: 1) voltage control capability of SVC is dependent on the var reserve margin, weakened by static voltage characteristics of the load and system, and improved by var dispatch with synchronous machines; 2) controllable voltage drop with limited var reserve is improved by higher slope or lower reference voltage, thus to yield less var output and coordinate SVCs at different locations with different operation conditions.