Control methods to achieve soft-transition of gains for a variable (n/m)X converter

摘要

Switched capacitor based converters derived from the original Dickson converter have a huge potential in meeting high power density and high efficiency demands of the power electronics industry. Originally, this type of converters offered high efficiency only at fixed voltage gains. Recently, a variant of the Dickson converter, termed as the (n/m)X converter has been proposed. The (n/m)X converter can achieve variable and fractional gains without compromising its efficiency. But, higher peak input transient current during transition from one gain level to another may lead to over-voltage stress across individual devices when compared to the fixed-gain switched capacitor converters. This is a limiting factor as the power level is increased. In this paper, two control methods are proposed to reduce/eliminate this peak current transient occurring during gain transition from one level to another. The over-voltage transient across individual switches is also eliminated. Experimental results from a 1-kW prototype validate the proposed methods.