Abstrato

Photovoltaic Controller with CCW Voltage Multiplier Applied To Transformerless High Step-Up DC?DC Converter

Elezabeth Skaria, Beena M. Varghese, Elizabeth Paul

This paper proposes a photovoltaic controller using high step-up dc-dc converter having both three stage and five stage multiplier based on the Cockcroft-Walton (CW) voltage multiplier without a step-up transformer, which provides continuous input current with low ripple and high voltage ratio. For a given input voltage, an output voltage boost up of same value can be generated for both 3-stage and 5-stage multiplier, with the components of reduced specifications. The proposed converter can provide a suitable dc source for any level multilevel inverter. In this paper, the control strategy employs two independent frequencies, one of which operates at high frequency to minimize the size of the inductor while the other one operates at relatively low frequency in order to have a desired output voltage ripple. A 200-W laboratory prototype is build for test, and both simulation and experimental results demonstrate the validity of the proposed converter.