Modeling and Guaranteed Cost Control of Three-phase APF Based on Switched Linear System

The high performance control of three-phase APF with hybrid dynamics is investigated in this paper. First, the hybrid dynamic uncertain model of the APF is transformed to a equivalent discrete-time switch linear uncertain systems (EDSLS) based on the pulse-width modulator (PWM) theory. Then, the EDSLS is further transformed to a linear equivalent discrete-time switch linear uncertain system by linearization at some neighborhood of the equilibrium manifold with respect to the pulse width. Finally a robust guaranteed cost controller is designed with on-time tracking property, where, in order to avoid the equivalent duty cycle treatment in the conventional controller design, the pulse width is adopted as the control variables. The proposed control scheme has clearer and more rational physical significance and can be easily adopted in practice. Simulation results illustrate the effectiveness of the proposed APF model and the control strategy.