A Daily Optimization Method for a PV-Battery Microgrid Considering the Battery Lifetime and Time-of-Use Pricing

A predictive optimization method for a four-terminal photovoltaic (PV) - battery hybrid microgrid is proposed in this paper. This hybrid system has a generation terminal, a battery energy storage terminal, an isolated dc-dc converter and an grid-connected converter (GCC) for load connection. The proposed optimization method aims to minimize the expense of hybrid system operation when grid-connected. The battery lifetime losses model, the PV panel losses model and the time-of-use electricity (TOU) prices are all considered in the optimization. A simulation is performed to verify the economic performance of the optimization method. Different optimization algorithms are compared in the simulation study to get the global optimum. The simulation results shows the benefit of the proposed daily optimization method. Some scenarios tested in the experimental study shows good transient performance.