Lifetime-Oriented Control Strategies for Hybrid Energy Storage Systems in an Islanded Microgrid

Alternative energy sources are becoming more important to ensure the supply of adequate and reliable energy. This forecloses environmental damage by outdated power plants and fossil fuel stocks, which are finite and have to be produced laboriously. Thus, energy management strategies for an islanded smart grid with combined energy storage systems, namely flywheel and battery storage, have been investigated in this paper. Mathematical models for these storage systems were developed in Matlab by analysing typical parameters and characteristics and were derived from simplified equations. Other microgrid components, the load profile, and photovoltaic (PV) system, were based on existing measurement data. Various control algorithms based on the battery's state of charge (SOC), load profile, and available PV power were developed in this paper. The simulations were done for a detached house and settlement for different scenarios including control strategies with and without different flywheel control algorithms. Finally, a reduction of the battery cycles and an increase of maximum off-grid mode time was achieved.