Power management and control strategies for efficient operation of a solar power dominated hybrid DC microgrid for remote power applications
In this paper, a hybrid DC microgrid consisting of a diesel generator with a rectifier, a solar photovoltaic (PV) system and a battery energy storage system is presented in relation to an effective power management strategy and two different control techniques implemented for power electronic interfaces. The solar PV and battery energy storage system are considered as the main source of energy that supply the load demand on a regular basis whereas the diesel generator is used as a backup for the emergency situations. All system components are connected to a common DC bus through an appropriate power electronics devices (e.g. rectifier systems, DC/DC converter). Also a detailed sizing philosophy of all components along with the power management strategy is proposed. Monthly basis energy distribution patterns of each individual component have also been presented. The power delivered by the solar PV system and diesel generator is controlled via DC-DC converter and excitation controller which are designed based on a linear quadratic regulator (LQR) technique as well as proportional integral (PI) controllers. The component level power distribution is investigated using these controllers under fluctuating load and solar irradiation conditions and comparative results are presented.