Linear and Nonlinear Advanced Control of Switching Power Converters

This chapter provides tools to control switching electronic power converters. It starts by explaining techniques to obtain linear state-space converter models, illustrating them through examples. Linear models are then used to design linear feedback controllers for converters operating in the continuous or discontinuous mode. Nonlinear state-space models and sliding-mode controllers are next used to define exactly the variables to be measured while providing the control and switching laws aiming for robust modulator and controller design. Predictive control uses a detailed nonlinear dynamic model to forecast the converter’s future behavior upon application of every possible converter switching state or vector. The best vector is then applied to the converter by computing the minimum of a cost functional. Fuzzy control needs expert qualitative knowledge of the converter dynamics. The steps to obtain a fuzzy controller are described, and the provided example compares the fuzzy controller performance to current-mode control. The backstepping control methodology is explained using a recursive procedure interconnecting the selection of the candidate Lyapunov function with the design of the feedback control loop to obtain stability and robust control under conditions less restrictive than other methods. A method to compute the backstepping controller gains is also presented.