Constrained reference tracking for a high-speed buck converter

Buck converters are ubiquitous in modern electronics, providing well regulated supply voltage to processing units and other integrated circuits, as well as to many other loads. In many applications, e.g., power supplies for processors, the reference for the output is piecewise constant, and typically the power converter must effectively reject disturbances due to fast changes in the load behavior. Furthermore, the stress on the converter components must be kept within specified limits to ensure increased life-time and high reliability of the end equipment. To answer this challenge, this paper investigates a previously proposed set-theoretic method for constrained reference tracking, and extends the approach towards handling additive disturbances which can be either measured or estimated. Within the method a nominally stabilizing control law and the associated domain of attraction are exploited to define the tracking control law which inherits the domain of attraction from the stabilizing one even in the presence of bounded additive disturbance. The approach is experimentally validated on a real-life buck converter and the measurement results are provided. Although, the control solution is illustrated on a buck converter only, the result is generic, and can be applied to any power converter with a linear averaged model.