A Mixed LQRI / PI based Control for Three-Phase UPQCs

A mixed linear quadratic regulator with an integral action control technique applied to a unified power quality conditioner (UPQC) is presented. The proposed control approach becomes a robust strategy that is able to keep regulation and stability even under extreme parameters and load power factor variations. The design of the controller parameters uses the well known Riccati equation based on the discrete approximation of the linear model of the UPQC. Key waveforms based on simulated extensive work shows the feasibility of the proposed approach