Adaptive pulse width modulation design for power converters based on affine switched systems. (November 2018) - Baldi, Simone
Abstract: In this work we propose a novel adaptive switching strategy for the design of pulse width modulation signals in power converters. Instead of an uncertain averaged model of the power converter, an uncertain switched model is considered, which can better represent the actual power converter dynamics. Uncertainties in the power converters parameters are handled via an adaptive control approach, and all circuit parameters of the switched model are assumed to be unknown (including the load and parasitic effects). After defining the pulse width modulation in terms of a reverse mode-dependent dwell time, an elementary-time-unit Lyapunov function is used to derive a set of linear matrix inequalities (LMIs) based on global uniformly ultimately boundedness of the switched system. The LMIs are solved in an adaptive fashion using an exploitation–exploration mechanism: exploitation is achieved by solving the LMIs based on the estimated switched model, while exploration is achieved by a persistently exciting input voltage source, which guarantees convergence of the estimated parameters to the true system parameters. Highlights: A switched model is considered to better represent the actual power converter dynamics. A (reverse) mode-dependent dwell-time strategy takes into account limited switching frequency. We take into account deviations from the ideal state due to parasitic effects. Full switched parametric uncertainty is considered.