Multi‐stage coordinated dynamic VAR source placement for voltage stability enhancement of wind‐energy power system

Abstract

Increased wind power penetration and induction loads have deteriorated the voltage stability performance of the power system. This study proposes a multi-stage multi-objective dynamic VAR source placement method for wind energy power system, where three sub-objectives are optimised simultaneously: (i) investment cost and operational control cost; (ii) steady-state voltage stability index; (iii) short-term voltage stability index. This method coordinates the dynamic VAR allocation decisions with preventive and corrective stability controls, including wind power curtailment, modification of the line drop compensation, and load shedding, to improve both steady-state and short-term voltage stability of the system. A robust parameter design technique called Taguchi's Orthogonal Array Testing is used to model the wind power uncertainty. Pareto optimal solutions are obtained for flexible decision-making. The computation burden is mitigated by candidate buses selection and critical contingency identification. The proposed model is demonstrated on the New England 39-bus test system using PSS®E. Compared with conventional approaches, it can achieve higher voltage stability level with less overall cost and moderate wind power curtailment, and at the same time avoid the conservativeness of planning decisions.