Mixed-sensitivity based robust H∞ controller design for high-gain boost converter

In this paper, a H∞ robust controller is designed for high-gain boost converter (HGBC) using mixed-sensitivity method. This controller design is based on the model, which uses a linear time-invariant approximation of nonlinear time-variant PWM converter that describes approximately the behavior of the system. The design of voltage-mode controller for boost converter is challenging, as its duty cycle to output voltage transfer function has a right half plane zero (RHPZ), shows non-minimum phase (NMP) behavior. Considering the mixed-sensitivity analysis into account the H∞ controller is designed to stabilize and guarantee a constant output voltage regardless of perturbations in input voltage and load. The closed-loop HGBC system is simulated in PSIM simulator, which shows excellent voltage regulation in presence of load and source disturbances. This clearly indicates that the mixed-sensitivity based H∞ controller yielding better performance and do not depend on the operating point of the converter.