A Unified Control Strategy Based on Phase Angle Estimation for Matrix Converter Interface System

Distributed generation based on high-speed generators is evolved dramatically. This paper presents a current-controlled matrix converter (MC) for interfacing microturbine generators. A unified control strategy is introduced to operate the MC interface in either isolated or grid-connected modes. The proposed control system is based on the instantaneous tracking of the phase angle which eliminates the need of using phase-locked loop circuits. The H_∞ algorithm is proposed for the phase angle estimation at the point of common coupling (PCC). In the grid-connected mode, the MC interface is utilized not only to control the active power flow but also to manage the reactive power fed to the grid. This utilization adds a capability to the MC interface for voltage regulation at the PCC. One advantage of the proposed unified strategy is that the structure of the controller remains unchanged for the different operating modes. Simulation results are provided to evaluate the performance of the proposed control technique of the current controlled MC interface system for multifunction operation.