Bidirectional power converter with adaptive controller applied in direct-current microgrid voltage regulation

Recently, many researches have been done related with the integration of distributed generation in the distribution system. However, in large scale applications, there are several challenges in terms of control design. A simple example is the possibility to operate in island mode or connected to the main power. The operation in island mode requires that power sources should be inserted inside the microgrid structure. The use of dc microgrid is increasing because of advantages in the integration of dc charges, dc loads and storage systems through electronic converters. Between theses advantages, the elimination of frequency are reactive power control are highlighted. However, this simplification does not exempt the microgrid from stability problems, in order to achieve different voltage levels for several power devices. These converters introduce destabilizing effects on the system, leading the microgrid to show significant oscillations in the dc bus voltage. The converter control is the primary concern in operating a microgrid. This work presents a dc microgrid operating in island mode. An adaptive controller is designed to control the balancing of power through a dc-dc bidirectional converter. This converter is connected to a storage device, controlling the dc bus voltage. Simulation results allow us to validate the proposed controller under variations in the availability of energy sources and during load changes.