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This paper presents a pulsewidth modulation dc-dc nonisolated buck converter using the three-state switching cell, constituted by two active switches, two diodes, and two coupled inductors. Only part of the load power is processed by the active switches, reducing the peak current through the switches to half of the load current, as higher power levels can then be achieved by the proposed topology. The volume of reactive elements, i.e., inductors and capacitors, is also decreased since the ripple frequency of the output voltage is twice the switching frequency. Due to the intrinsic characteristics of the topology, total losses are distributed among all semiconductors. Another advantage of this converter is the reduced region for discontinuous conduction mode when compared to the conventional buck converter or, in other words, the operation range in continuous conduction mode is increased, as demonstrated by the static gain plot. The theoretical approach is detailed through qualitative and quantitative analyses by the application of the three-state switching cell to the buck converter operating in nonoverlapping mode (D < 0.5). Besides, the mathematical analysis and development of an experimental prototype rated at 1 kW are carried out. The main experimental results are presented and adequately discussed to clearly identify its claimed advantages.Index Terms-Buck converter, dc-dc converters, three-state switching cell (3SSC).

This paper introduces a bridgeless boost converter based on the three-state switching cell for PFC (power factor correction) applications, whose distinct advantages are reduced conduction losses with the use of magnetic elements with minimized size, weight, and volume. The approach also employs the principle of interleaved converters, as it can be extended to a generic number of legs per winding of the autotransformers and high power levels. The theoretical analysis of the proposed converter is developed, while a comparison with the conventional boost converter is also performed. An experimental prototype rated at 1 kW is implemented to validate the proposal, as relevant issues regarding the novel converter are discussed. 1 I. INTRODUCTION

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