Adaptive Current-Mode Control of a High Step-Up DC-DC Converter

A new adaptive current-mode control of a high step-up DC-DC converter is presented. The converter gives a very high voltage gain without using a transformer and maintains low voltage stress across the power devices. The adaptive controller is formed by combining the existing current-mode control law and an adaptive law that generates the inverse of the load resistance. The structure of the proposed adaptive law is such that the derivative of the estimate is both optimized and bounded. To facilitate the controller design, the derived averaged state-space model of the converter with parasitic elements is used. An approximate stability analysis is carried out to gain some insight into the behavior of the adaptive-controlled system. Some experimental results comparing the performance of the proposed adaptive current-mode controller with that of the existing current-mode controller are also presented.