PROPOSAL, ANALYSIS AND EXPERIMENTAL VERIFICATION OF NONISOLATED DC-DC CONVERTERS CONCEIVED FROM AN ACTIVE SWITCHED- COMMUTATION CELL

Mauricio Dalla Vecchia1, Jéssika Melo de Andrade2, Neilor Colombo Dal Pont2, André Luís Kirsten2 Proposal, Analysis and Experimental Verifi cation of Nonisolated 2DC-DC Converters Telles Brunelli Lazzarin Conceived from an Active1 EnergyVille, Switched-Capacitor KU Leuven, Commutation Kasteelpark Arenberg Cell 10, Heverlee, Belgium Mauricio Dalla2 Department Vecchia, of Jéssika Electrical Melo Engineering, de Andrade, Federal Neilor University Colombo of Santa Dal Catarina, Pont, Florianopolis André - SC, Brazil Luís Kirsten,e-mail: m.dallavecchia90@ Telles Brunelli Lazzaringmail.com; [email protected]; [email protected]; [email protected] [email protected]

Abstract – This paper introduces a new family of impedance source circuit [3], [17], [18], series and parallel nonisolated dc-dc converters that are generated by the connections [19], [20], ladder [12], [14] and stacked integration of the active switched-capacitor (ASCC) and connection [21]–[23] have provided alternative ways to the conventional commutation cell (CCC). Based on the obtain high gain, but all of them use a higher number of commutation cell concept, the new conceived hybrid components. active commutation cell (HACC) provides three different The switched capacitor (SC) principle is one way to types of hybrid converters: buck, boost and buck-boost. multiply or divide dc voltage. The SC converters are applied All three converters are investigated in this study in boost topologies [10], [24], [25] as well as in buck through the following approaches: topological stages, topologies [26]. They are capable of supplying a high static gain analysis considering the switched - capacitor conversion ratio and they are magneticless topologies. features, generalization of the HACC and gain for M cells Almost all the structures have good voltage stress sharing and steady-state analysis. The buck version presents a across components and, when they are properly designed, high conversion rate, which demonstrates that it has they can provide high efficiency, high power density and low potential for step-down applications. To verify the weight [27]. However, the output voltage regulation is not as proposed topologies, a prototype was built with the easy as in a conventional converter and this represents a following specifications: 600 V input voltage, 150 V challenge in the design of SC converters. Many authors have output voltage, 70 kHz switching frequency and 1 kW addressed this issue in the literature [10], [26]. rated power. Efficiency close to 95% was obtained at On the other hand, the conventional converters present 1 kW for the buck topology, which demonstrates that the good output voltage regulation, but are not capable of proposed HACC can provide gain and high efficiency at providing a high conversion ratio. Hence, the integration the same time. between SC and conventional circuits could allow the combination of the advantages of the two groups of Keywords – Active Switched-Capacitor Cell, converters while overcoming the drawbacks [7], [11], [26]. Commutation Cell Concept, Experimental Results. This new family of converters is referred to in the literature as hybrid converters. I. INTRODUCTION In general, SC cells are integrated with conventional converters to generate new topologies [7], [11], [28]-[30]. The recent growth in the development and use of HVDC However, this concept was approached in relation to transmission systems, DC distributed systems, DC smart commutation cell, and a passive ladder SC cell was grids, electrical vehicles, energy storage systems, renewable integrated with conventional commutation cell [11]. The new sources, and telecommunication systems has enhanced the converters are analyzed through the commutation cell. need for new solutions for dc-dc conversion. This scenario In this context, this paper proposes a hybr