Control of power converters with hybrid affine models and pulse-width modulated inputs

Abstract

Abstract|In this paper, hybrid dynamical systems theory is applied to the analysis and control of switched converters with Pulse-Width Modulated (PWM) inputs. The system is described by a state-space model with continuous ows and discrete jumps, without averaged equations. The modulation e ects are captured in full without using time-dependent signals, by enlarging the state vector to include the PWM waveform generation process. Furthermore, the sample-and-hold mecha- nism associated with the sampling frequency is also taken into account with this approach. A control law is proposed based on a Lyapunov function candidate. Furthermore, convergence sets and the steady state jitter, inherent to PWM-based controllers, are analyzed estimating limit sets for the augmented state. Consequently, output chattering can be bounded. By using hybrid dynamical system theory, the control designer gains a deeper understanding of the e ect of modulation in the closed- loop dynamics, avoiding the problems associated with the use averaged models. Experimental results validate the proposed method.