Robust structured controller synthesis for interleaved boost converters using an H-infinity control method

The regulation of output voltage and equivalent distribution of phase currents of multi-phase converters which have non-minimum phase characteristic are still challenges, especially in the presence of uncertainties in real parameters, duty cycle, input voltage, and load disturbances. However, in classical third-order integral-lead (Type-III) controller design methodologies, the controller is synthesized considering only the nominal performance conditions. This paper proposes a structured H-infinity synthesis framework based on an optimization methodology to the design of a robust Type-Ill controller for interleaved boost converters. The structured H-infinity. control approach is adapted for optimization of Type-III feedback and feedforward controllers in two-degree-of-freedom (2-DOF) control system configuration. The robust stability of the closed-loop interleaved boost converter system against model uncertainties is ensured via the classical mu-analysis technique. Numerical comparisons are made among the classical, i.e. unstructured or full order, H-infinity-based controller design method, a dual-loop PI controller, and proposed I-DOF and 2-DOF structured controller synthesis approaches on an interleaved boost converter model. Simulation results verify the effectiveness and advantages of the proposed approach from the viewpoint of the output voltage regulation under different disturbance points.