Abstract
In this paper, a method of maintaining high power conversion efficiency across the entire load range of a three-phase micro-inverter is proposed. The proposed control method substantially increases the conversion efficiency at light loads by minimizing switching losses of semiconductor devices as well as core losses of magnetic components. This is accomplished by entering a phase skipping operating mode wherein two phases of an inverter are disabled and three inverters combined to form a new three phase system with minimal grid imbalance. The performance of the proposed control method was evaluated on a 400W, 208VAC three-phase micro-inverter.