Controller order reduction for robust control of parallel operating dc/dc converters

A useful straightforward controller order reduction procedure for multivariable robust control is presented. Reduced controllers regarding robust stability criterion and robust performance criterion are developed. Weighted Balanced Truncation is used as the concept for the real reduction work. The procedure is applied to Loop Shaping Design Procedure, Internal Model Control and Decentralized robust controllers of parallel operating dc/dc converters. Uncertainty robustness and performance of the closed-loop systems with reduced controllers are investigated. The reduction procedure efficiently decreases high controller orders, from which robust theory suffers, preserving at the same time closed-loop robust stability and robust performance at a desired level.