Small-signal model and analysis of a multiple feedback control scheme for three-phase voltage-source UPS inverters

This paper presents a small-signal model and analysis of a current-controlled, voltage-regulated three-phase voltage-source inverter for uninterruptible power supplies (UPS). Using perturbation and small-signal analysis techniques, linear steady-state and dynamic models of the UPS system in the rotating frame of reference are derived. The small-signal model is used to study the effects of various feedback variables on the dynamic performance of the UPS system. Experimental results are provided to validate the analytical models.