Dynamic Optimal Power Flow for Microgrids Considering Efficiency and Lifetime of Battery Using MINLP

This paper proposes an approach to operate optimally microgrids considering battery efficiency and lifetime. The microgrid system consists of several generators such as diesel generators, microturbines, photovoltaics, wind turbines, and battery. It is assumed that the battery belongs to an ancillary service provider. Therefore, a different price for battery charge and discharge transactions is applied. In addition, battery efficiency and lifetime are also incorporated into the operation problem. The problem is formulated as Dynamic Direct Current Optimal Power Flow (DDCOPF). The objective function is to minimize generation cost and line losses, as well as to maximize battery lifetime. However, unlike other standard DDCOPF, network losses modeled as the quadratic equation are included in the problem formulation. As formulated problem comprises discrete and continuous variables, Mixed Integer Non-Linear Programming (MINLP) is used to solve it. In order to show the effectiveness of the proposed approach, a modified IEEE 30 bus is used as a test system.