High-Efficiency Interleaved $LC$ Resonant Boost Topology: Analysis and Design

Abstract

Due to its simplicity, the hard-switching boost converter is widely used in many applications, such as renewable energy and power factor correction. The power density of the converter can be increased with smaller magnetics; however, this requires an increase in the switching frequency. Therefore, it is necessary to provide soft-switching conditions to minimize the switching losses. In this paper, a new resonant step-up converter and the associated analysis are presented. The proposed interleaved LC resonant boost converter provides soft switching for all of the semiconductor elements even under light loading conditions. Small inductors with discontinuous conduction mode (DCM) currents can be used because the interleaving behavior ensures a continuous input current with low ripples. The interleaving also reduces the output capacitor ripple current. Burst mode operation has been applied to improve the efficiency of the converter during light loading conditions. Detailed design methodology and the control strategies are provided. To show the validity of the theoretical analysis, experimental results are provided for a 400-W prototype, and are compared to a benchmark conventional interleaved boost converter with the same components. Substantial efficiency improvements are achieved for different loads and voltage gains, particularly under light loading conditions.