High-power-factor single-stage converter with robust controller for universal off-line applications

This paper presents a robust-controlled single-stage converter (SSC) operat ing either in discontinuous conduction mode (DCM) or in continuous conducti on mode (CCM) to achieve high power factor for universal Line voltage range from 90 to 264 V-rms. At light load, the proposed system is operated in th e DCM, while at heavy load the system is operated in the CCM, thus, the de- link voltage can be properly controlled within a certain voltage range and the efficiency can be improved as well. The overall system is with a robust controller and is operated in a fixed frequency. In the design, the load v ariation and line voltage variation are treated as plant uncertainty and co ntrol disturbance, respectively, The H-infinity robust control method is ad opted to design a proper robust controller to achieve robust stability and robust performance, The measured results from a prototype have confirmed th e effectiveness and feasibility of the proposed system.