Energy management strategies based on hybrid automata for islanded microgrids with renewable sources, batteries and hydrogen

In this work, an energy management strategy is proposed for the control of islanded off-grid energy systems with energy storage based on renewable energy sources. The proposed supervisory control framework is based on a hybrid automata algorithm which is combined with propositional-based logic, describing the transitions between different operating states of the integrated system's components. The algorithm can be extended to a variety of cases without compromising the operational objectives. Within the paper, four example cases of application are given. These example cases correspond to different load demands (industrial & residential) as well as different renewable energy sources including solar, wind, hydropower and biomass. In all cases the energy is stored in a combination of batteries and hydrogen (via electrolysis) and then used back in a fuel cell. Compared to the current energy solutions in the example cases based on diesel generation sets, a 95.6%-99.4% curtailment of fossil fuel consumption is achieved. The control algorithm manages to supply power without interruption to the current loads while ensuring the health of the storage components.