Optimal power flow with distributed energy storage dynamics

Abstract

Restructuring of the electric power industry along with mandates to integrate renewable energy sources is introducing new challenges for electric power systems and the power grid. Intermittent power sources in particular require mitigation strategies in order to maintain consistent power on the electric grid. We investigate distributed energy storage as one such strategy. Our model for optimal power flow consists of simple charge/discharge dynamics for energy storage collocated with load and/or generation buses cast as a finite-time optimal control problem. We illustrate the effects of energy storage using a modified version of the IEEE 14 bus benchmark example along with time-varying demand profiles. We use both time-invariant and demand based cost functions. The addition of energy storage along with demand based cost functions significantly reduces the generation costs and flattens the generation profiles.