Digital control system design for a Cuk converter

Cascade control system design for a Cuk converter with pulse-width modulator in control loop is discussed. Proposed control system consists of two cascades. Inner one maintains input current by PI controller with an additional low-pass filtering. In outer one the third-order controller provides output voltage regulation. Analytical expressions are derived for digital implementation of the proposed control laws by microcontroller. Numerical simulation results are presented.

I. Introduction

DEVELOPMENT OF CONTROL SYSTEM design methods for the Cuk converter is discussed in a set of research works as far as such converters are widely used in various industrial applications [1]–[8]. The behavior of the transients in the Cuk converter exhibits complicated nonlinear dynamic. Moreover, specific dynamic nature of the Cuk converters demands to design cascaded control systems in order to avoid the appearance of instable internal dynamics [5]. In should be noted that from practical point of view the recent control techniques are implemented based on microcontrollers then, it is urgent need to get analytical expressions for digital control system design. Applications of singular perturbation technique [9]–[12] in order to develop procedures of the cascade control system design for the Cuk converter have been done in [13], [14]. The main objective of this paper is to derive analytical expressions of digital control laws for the Cuk which can be implemented by microcontroller.