Full Digital Control of a Single-Phase Series-Parallel Uninterruptible Power Supply

In this paper, a new digital deadbeat controller is designed, implemented, and applied to a single-phase series-parallel line-interactive uninterruptible power supply (UPS). In this topology, most of the power is supplied directly from the AC line to the load. Therefore, the overall efficiency is higher than that of the conventional on-line UPS. Current and voltage control of the system in different operating modes are discussed. Simulation and experimental results are presented, which show the viability of the proposed controller for this topology.