Decoupling Sliding Mode Control of Buck Converters with Consideration of Non-minimum Phase Characteristics

In this paper, a novel decoupling sliding mode (SM) control approach is proposed for buck converters with arbitrary order to solve their inherent problems of non-minimum phase and the chattering. Based on the concept of relative degree, a new form of sliding surface with hieratical structure is proposed. As a result, the problem of the non-minimum phase is solved and the system is decomposed into two parts, i.e., an input-output subsystem and a zero dynamic subsystem. In order to guarantee the system stability, the corresponding robust control law is proposed on the basis of the Lyapunov theorem. In order to solve the chattering problem, the boundary layer is introduced to achieve the control continuity. Comparative simulation results validate this paper.