Robust Design and Controllability Analysis for Voltage Mode Controlled Multiport Converter With Structured Uncertainties

ABSTRACT This paper presents a robust voltage‐mode controlled (VMC) strategy and controllability analysis of a time‐multiplexed dc‐dc multiport (TMDCM) converter for non‐minimum phase (NMP) conditions. The instability mitigation is presented using a systematically designed PI controller using the stability boundary locus (SBL) method and Kharitonov's theorem, incorporating structured uncertainties and external disturbances. A robust stability region is defined within the K p and K i plane, and a section with optimal gain values to meet the desired performance criteria. The proposed approach uses voltage feedback from both the output ports of the TMDCM converter. Additionally, it inherently accounts for input and load variations, enhancing voltage regulation performance. A robust single‐loop voltage‐mode controller with structured uncertainties is analytically designed for a time‐multiplexed switched‐boost converter exhibiting a right‐half‐plane (RHP) zero. The switched‐boost mechanism, combined with time‐multiplexed control, enables a multiport converter output that provides bidirectional functionality for charging and discharging management of the battery energy storage system, along with other load output ports. The laboratory prototype is developed, and the real‐time performance of the converter is demonstrated for effective voltage regulation under varying source and load conditions, confirming controller robustness, non‐fragility, and improved disturbance rejection.