Dual-Switch Enhanced Gain Boost DC–DC Converters

Abstract

A switching capacitor-based boost converter topological evolution is proposed in this article. Switching capacitor with dual-switch configuration is the basis for the topological evolution with common ground feature. The topologies evolved are capable of yielding high-voltage transformation ratio at smaller duty ratios like in Z-source dc–dc converter topologies. The front-end structure provides a voltage gain of 1/(1 − 2D) while the upstream circuit structure is compatible for embedding the voltage multiplier cells and thus gain enhancement becomes an easier task. On this basis, four different enhanced gain boost topologies with common ground feature [dual-switch-based switching-capacitor converter (DSSCC) Type-1 and -2, and dual-switch-based switching-capacitor fourth-order converter (DSSCFO) Type-1 and -2] are introduced in this article. In all these topologies, a small adjustment in the duty cycle is sufficient enough to ensure load voltage regulation even if the input supply voltage varies over wide ranges. Among these four proposed topologies, DSSCC Type-1 and DSSCFO Type-2 exhibit low source current ripple content due to the presence of inductance at the source side. Of these two, DSSCFO Type-2 exhibits low source current ripples as well as high voltage gain at moderate duty ratios. In view of this, detailed analysis and experimental investigations are established for DSSCFO Type-2. A comprehensive comparison of the proposed topologies with other reported topologies is given, wherein they exhibit identical as well as closely following voltage gain. A 220 V, 120 W, 50 kHz prototype is constructed for performance verification. Measurement results are provided to demonstrate the enhanced gain boosting along with low source current ripple features.