Seamless transfer of three-phase grid-interactive microturbine inverter between grid-connected and stand-alone modes

This paper deals with required power electronics interface for a 70 kW microturbine-based distributed Generation system. First, an introduction of microturbine technology and its applications is presented, and then the power electronics interface that is required to transfer microturbine´s output power to an islanded local load or an electric power grid is described. Different control strategies for controlling the inverter in stand-alone and grid connected modes and the seamless transfer between two modes are described in this paper. To show effectiveness of the designed inverter and its digital controller the experimental results based on a constructed 70 kW semi-industrial setup has been demonstrated.