Operating reserves with flexible loading in electricity market

Abstract

This paper proposes an extended multiple time-step optimal power flow (OPF) model to schedule both energy and operating reserves with load flexibility. Flexible loads can shift demands among time steps under certain constraints to meet their energy consumption requirements. Therefore, peak and trough demands/prices can be more moderate. In addition, a portion of flexibility is able to provide operating reserves, especially regulation reserves, since flexible loads are able to react instantly with digital controls and high speed communications by using smart grid technologies. Flexible loads can be classified into two categories: energy storage flexible loads (ESFLs) and energy consumption flexible loads (ECFLs) by their characteristics of energy consumption. An ESFL should maintain a certain amount of energy in the storage, and an ECFL usually consume a certain amount of energy before a deadline. Market analysis demonstrates the effectiveness of both models in energy dispatch and reserve allocation. Numerical examples show that flexible loads narrow both price and voltage distributions and reduce reserve prices/costs.