Frequency Dynamics Constrained Unit Commitment with Wind Plants

Abstract

With the increasing penetration level of renewable energy in power system, system inertia drops significantly, leading to a new challenge in frequency security. How to utilize the capability of wind plants in frequency regulation and incorporate it into the daily dispatch is not yet well addressed. In this paper, we proposed a frequency constrained unit commitment(UC) model with wind plants, combining different response strategies of wind plants and incorporating them into the UC model. A multi-stage integrated strategy is proposed with the combination of temporary response and persistent response of wind plants together with inertia and primary response of synchronous generators. Then a UC model with the incorporation of frequency dynamics and the response strategy is formulated. Piecewise Linearization and big-M methods are introduced to convert the nonconvex constraints into linear constraints. The numerical study validates the proposed method and shows the benefit of the proposed strategy in the aspects of wind integration and cost saving.