Relative Gain Array Based Decoupled Controller design for GaN-Based Multiple Output Flyback Converter

The recently proposed independently controlled multiple output flyback converter (ICMOFC) utilizes gallium nitride (GaN) switches with negative gate turn OFF voltage to improve cross-regulation between multiple output voltages. A cross-coupling between the control and output variables exists in such a multiple-input multiple-output control system. This cross-coupling leads to severe interactions between control loops if the conventional decentralized feedback compensators are designed for high closed-loop bandwidths. These interactions may affect the converter's dynamic performance. As a result, the attainable closed-loop bandwidth for non-decoupled decentralized control is limited. To address this issue, this paper delineates a methodology for decoupled controller design for the ICMOFC to attain a fast transient response. The effect of the right half-plane zero of the plant transfer function is also addressed in the suggested decoupled controller. Simulation and experimental results for a 40 W two-output flyback converter are provided to validate the suggested control scheme.