Predictive Control for Isolated Matrix Rectifier Without Current Distortion at Sector Boundary

Three phase active rectifiers are needed to supply dc loads from the ac distribution grid without introducing large distortions on the ac grid. Galvanic isolation is a requirement for many applications due to safety concerns. High frequency link power conversion topologies, based on indirect matrix converters, are an emerging solution for such applications. In this paper a predictive digital control is developed for an isolated three phase ac/dc matrix converter by combining a deadbeat controller and space vector modulation. This approach simplifies the controller design and allows for full-range soft-switching with sinusoidal input currents. Due to the discrete operating sectors of high frequency link topologies, an additional modulation mode is introduced near sector boundaries, reducing the distortion caused by sector changes. The proposed deadbeat controller is validated with PSIM simulations.