Modularly Expandable ZVS High-gain Converter With High Light-load Efficiency and Reduced Power Components
In this paper,a modularly expandable zero voltage switching(ZVS)high-gain boost converter with high light-load efficiency and reduced power components is proposed.The proposed converter can enhance voltage gain by increasing the number of step-up modules(n).It consists of 2 switches and(n + 1)diodes,which suffer from low voltage stress of[(n + 1)Uin + Uo]/(n + 2).In addition,the input inductor is operated in continuous conduction mode;other inductors are operated in continuous bidirectional conduction mode and the sum of their reverse peak current must be higher than the valley value of the input inductor current.Benefiting from this design method,all power semiconductors realize soft-switching.Besides,a flexible-switching-frequency control method is employed,which involves adjusting the switching frequency through a lookup table based on input voltage and load conditions.This approach limits the peak current of inductors to within a specified range.Consequently,the soft-switching condition is fulfilled,and the current stress and conduction loss are minimized,leading to an improved light-load efficiency.In this paper,the working principle,steady-state characteristics,soft-switching conditions,and control methods of the proposed converter are analyzed in detail,and the correctness of the theoretical analysis is verified with a 250 W experimental prototype.
Boost converterhigh voltage gainlow voltage stresszero voltage switching(ZVS)flexible-switching-frequency