Optimal scheduling of VAR devices considering wind power variability

This paper deals with the optimal short-term scheduling of VAR devices considering the volatile nature of wind power generation. These devices are utilized to maintain the voltage security in the forecasted wind power output case and its associated possible scenarios representing the wind power forecast errors. The random reactive power consumption associated with the wind power variability is included in the proposed formulation to demonstrate its impact on the power system voltage security. The problem is formulated as an optimization problem, where the objective function is to minimize the sum of the energy losses cost and operational cost of the reactive power devices. The consideration of the possible scenarios increases greatly the problem size. Therefore, Benders decomposition technique is employed to break down the intact problem into a master problem representing the hourly forecasted wind power and slave sub-problems relevant to possible volatility scenarios. The optimal VAR dispatch is obtained by iterating between the master problem and slave sub-problems. The proposed approach has been successfully tested on IEEE 14 bus system.