A new PWM control strategy for the buck converter

Abstract

A new PWM control strategy for the buck converters is presented. The proposed control strategy is based on the switching converter large signal average model linearization and use modern control theory to achieve the control laws for the expected response. Therefore, a new nonlinear PWM controller is made to implement the control law. The new nonlinear PWM controller development is based on the error between the switched variable and the control reference of expected system response to zero each cycle. As a result, the system transfer functions are derived as a function of the desired closed loop poles. Simplifying the design procedure and bringing forward all the important characteristics of the closed loop system. From a conventional control point of view: first, the proposed PWM control strategy such uses an observer approach both to reconstruct an inductor current state and to control the converter based on a current mode technique. Second, this technique also a method of indirectly implementing the sliding-mode control law. The proposed control strategy has significant advantages over conventional current mode control techniques in noise susceptibility, dynamic response and without inductor current sensing. Finally, the simulation results confirm the theory.