A Unified Compensator Design Based on Instantaneous Energy Equilibrium Model for the DC Link Voltage Control of UPQC

Suitable model for the analysis and control of the Unified Power Quality Controller (UPQC) was quite difficult to obtain, which prohibited not only the analysis and comparison between existing control strategies, but also the industrial applications, as no generalized method to design the control loop for different disturbances. In this paper, a unified DC voltage compensator design is proposed for UPQC based on the system instantaneous energy equilibrium model. The main circuit model of UPQC is derived firstly, including both the steady state model and the small signal model. Subsequently, four existing control strategies for the shunt converter control are found and modeled in detail, which are combined with UPQC main circuit model, and the whole control system are obtained accordingly. The UPQC whole system model are compared and evaluated in different disturbances. And then the unified compensator design method for the DC link voltage control is proposed, the worst control strategy is then chosen as an example for the detailed compensator design, based on the newly proposed model. Finally, the computer simulation and prototype experiment are done to verify the validity all the analysis and control.