Adaptive control design for the buck-boost converter with desired pole/zero assignment

Abstract

In this paper, an adaptive digital control scheme is proposed for the buck-boost converter using a desired pole/zero assignment approach. In the case that the plant parameters are well-known, through the sensitivity function a digital controller for the buck-boost converter with desired pole/zero assignment is proposed by solving some simple algebraic equations instead of solving a Diophantine equation to meet the requirements of internal stability for the closed-loop system. In the case that the plant parameters are uncertain, a digital adaptive controller for buck-boost converter is also proposed using the recursive least-squares (RLS) algorithm to estimate the uncertain parameters, where the desired poles and zero are still assigned for the sensitivity function with respect to the estimated parameters at each sampling step. A projection algorithm is proposed for the estimated parameters to satisfy the characteristics of poles and zero for a buck-boost converter, where poles should be inside the unit circle and zero should be outside the unit circle, respectively. To verify the validity of the proposed digital controller, experimental set-up is built for the buck-boost converter and the fully digital adaptive controller is implemented by a digital signal processor TMS320- F28335.