Feedback Linearization Control of Three-Phase UPS Inverter Systems

In this paper, a feedback linearization technique is proposed to control the output voltage control of three-phase uninterruptible power supply systems. First, a nonlinear model including the output $LC$ filters is derived from the power balance condition between the inverter output terminal and the load side. Then, input–output feedback linearization is applied to the nonlinear model to make it linear. The controller of the linearized model is designed by linear control theory. The tracking control law is obtained with a pole placement technique. It is shown experimentally that the proposed control scheme gives high dynamic responses in response to load variation as well as a zero steady-state error.