Economic Dispatch for EV Energy Storage-Integrated Power Systems

Abstract

Several economic and environmental considerations have made the transition to electric mobility inevitable. The power system can derive substantial benefits from this transition since Electric Vehicles (EVs) that are not in transit can be used as energy storage resources in the grid. Successful integration of EV energy storage into the grid requires the accompaniment of certain reforms in grid and market operations, one of which pertains to economic dispatch. In this paper, we address the problem of economic dispatch for a power system that has EV energy storage integrated into it. A quintessential feature that distinguishes EV storage from other forms of energy storage is that EV storage is unreliable: An EV could connect and disconnect from the grid at random times and so the availability of an EV's battery to the grid is intermittent and random. Consequently, the system operator cannot bank on the energy that it stores in an EV to be available for discharge at a future time. These aspects necessitate a rethinking of the economic dispatch problem when EV storage is integrated into the grid. The economic dispatch problem must account not simply for the availability of storage, but also the uncertainty in the availability. In this paper, we model these aspects and formulate the EV storage-integrated Economic Dispatch (EV-ED) problem. We also present an optimal, albeit computationally intensive approach to solving it. Methods to overcome the computational difficulty are briefly discussed.