DE-based two-stage reactive power planning with wind power penetration

This paper proposed a DE-based two-stage algorithm for power system reactive power planning with wind power integration. In the first stage, with the aid of the sensitivity analysis of Jacobin matrix from power flow program and the partial derivative of the reactive power injection to the node shunt susceptance, a new susceptance-based voltage sensitivity matrix consists of the partial derivative of the voltage to the shunt susceptance for each bus is obtained. The new matrix is used to narrow the boundaries of the compensation capacity with respect to the lower and upper bounds for the bus voltage. The second stage of the proposed method consists of a DE algorithm. The two-stage algorithm is designed to take advantage of the merits of each technique. The method of the first stage is employed to provide a good initial guess and to quickly and locally improve upon the solution provided by the DE with less computation. In this paper, the SVC device is used to minimize the real power losses and to improve the voltage profile during various operation scenarios disturbed by wind power variations. The model is formulated as a constrained optimization problem, where the constraint is to let the voltage of each bus close to 1 p.u. The proposed DE-based two-stage method has been tested in a modified version of the IEEE 30 bus system for 6 scenarios of different wind speed levels and compared with the typical DE one with satisfactory results.