A user energy management system (UEMS)-based microgrid economic dispatch model

Abstract

The economic dispatch of a microgrid is usually modeled as an optimization problem. In much of the literature, controllable loads of users are gathered and regarded as virtual power plants and become a part of the economic dispatch in order to minimize costs and maximize consumption of renewable energy. However, the cost function of different users at different times is difficult to determine because of incomplete information regarding users. To this end, this paper proposes a microgrid economic dispatch approach based on a user energy management system (UEMS). Each UEMS of the users schedules controllable loads based on the received day-ahead price curve to minimize costs greedily. A microgrid control center (MGCC) gathers the load profiles from each UEMS and solves the dynamic optimization power flow (DOPF) problem. The day-ahead price is determined by the marginal cost and acts as a virtual hand to coordinate the MGCC and UEMS. In addition, as an example of a typical controllable load, a schedule model for inverter air conditioner is proposed. A numerical example shows that this approach can minimize overall costs and promote the consumption of renewable energy.