Optimal voltage control by wind farms in distribution networks using regression techniques

Due to the extensive growth of the wind power penetration, the frequency and voltage control by this technology must be evaluated. This paper will focus on the voltage control of
the distribution network which connects the different wind farms of an area to the transmission network bus. The aim of this control is the minimization of the distribution losses while keeping away the system from voltage collapse. This paper investigates if it possible to assess accurately the optimal voltage control of wind farms using simple regression functions instead of running an Optimal Power Flow (OPF) each time. It is proposed to evaluate the relation between selected explanatory variables and the objective function. In order to perform this relation three steps are needed: (a) a data base of optimal operational scenario built using a genetic algorithm, (b) selection of explanatory variables, and (c) developing of regression rules of the optimal voltage control. The methodology proposed in this paper is illustrated considering an actual distribution network
comprising 13 wind farms of the Spanish power system.