Nonlinear frequency and voltage regulation in a PV-battery-diesel microgrid

Modern power networks require flexibility in control to maintain generation-load balance under severe disturbances. Several infrequent sources have integrated power systems to contribute to electrical power production. The increasing penetration of renewable sources as alternative generations introduces new serious challenges to power systems due to their natural variations. Furthermore, power systems with renewable sources have significant nonlinear behavior. These nonlinearities, fluctuations and other common uncertainties in power systems make traditional controllers unable to perform appropriately over a wide range of operating conditions. To address these challenges, the present paper proposes nonlinear controllers to regulate voltage and frequency in a micro power grid that includes a photovoltaic, a battery and a diesel generator. The input-output feedback linearization technique is used to obtain the controller equations. An adaptive nonlinear MPPT controller is also designed to control the PV generator smoothly and fast. The performance of the proposed technique is tested in simulation.