Impact of correlation on reserve requirements of high wind-penetrated power systems

•Investigating wind farms output correlation effect in reserve of power system.•The proposed framework is founded based on an analytical approach.•The adequacy studies of power system are addressed based on the proposed method.•It provides guidelines for decision makers in determining reserve of the system.

This paper investigates the effects of two important factors, i.e., correlation of wind farms output with load and wind speed coincidence in determining the required static reserve in a high wind-penetrated power system. To this end, it suggests an analytical approach to involve the effects of these two factors in probabilistic analytical multi-state models of wind farms output generation. Based on an optimization framework with the objective of reaching the desirable level of correlation, the key idea is to calculate some joint probabilities for equivalent models of wind farms. As a result, these models become compatible with the ones for conventional generation units in adequacy studies of power systems. The proposed analytical approach, then, continues with evaluating the reliability level of power systems exactly and also practically employing these multi-state models once dealing with wind farms at multiple locations. The proposed analytical approach is applied to the modified IEEE-RTS and the obtained results and discussions offered demonstrate the unavoidable effects of these important factors (load and wind speed coincidence) in real world applications.