Optimal allocation and sizing of dynamic VAR support to improve short-term voltage stability considering wind farm and dynamic load model

Nowadays short-term voltage instability is a major threat for power system reliability and stability owing to the increasing proportion of renewable energy sources such as solar and wind power, induction motor loads, HVDC links and etc. The aim of this paper is to determine the optimal location and size of static VAR compensator (SVC) to counteract the short-term voltage instability. A multi-objective optimization problem (MOP) is defined to satisfy the two objective functions: 1) minimizing the whole investment cost 2) minimizing the undesirable behavior of transient voltage under multiple probable contingencies. Composite load model consisting of induction motor loads and other components is modeled accurately. Moreover, the system is considered with a high penetration of wind power. Severity and risk indices are proposed to measure the degree of transient voltage performances. Candidate buses for SVC deployment are determined based on trajectory sensitivity analysis. Genetic algorithm is employed to find optimal allocation of SVC. The effectiveness of proposed approach is verified on New England 39-bus system.