Single Stage High Voltage Gain Boost Converter With Voltage Multiplier Cells for Battery Charging Using Photovoltaic Panels Luiz H. S. C. Barreto; Paulo P. Praça; Gustavo A. L. Henn; Ranoyca N. A. L. Silva; Demercil S. Oliveira Energy and Control Processing Group - GPEC / Department of Electrical Engineering / Universidade Federal do Ceará Centro de Tecnologia - Campus do Pici, Bl.705 Fortaleza-CE, Brazil, 60455-760 / Phone: +55 85 3366.9586 E-mail: paulopp@dee.ufc.br, demercil@dee.ufc.br, lbarreto@dee.ufc.br Abstract— This paper presents a non-isolated high frequency DC-DC converter, which integrates a battery charger, photovoltaic panels, and a high voltage gain boost converter in a single conversion stage with soft-switching characteristic. The proposed topology uses voltage Multiplier Cells (MCs), leading do high voltage step-up. Also, the bidirectional behavior admits the DC bus to be generated via battery bank, or photovoltaic panels, or both, depending on the insulation condition. At last, experimental results validate the proposed topology, proving its effectiveness. I. INTRODUCTION The increasing use of renewable energies applications, such as photovoltaic panels, fuel cells, and wind turbines, is leading to new challenges for power electronics researches, particularly on distributed generation systems, isolated or not, smart grids, and grid-connected applications, which seems to be the future for the power electronic new technologies. The challenge to build a high output DC voltage bus (from 200 to 400Vdc), used to feed inverters, UPS, etc, from low input voltage levels, has been studied for some years now, which has leaded to several new converter topologies [1]. Recently, non-isolated DC-DC converters with high voltage gain have been highlighted in different applications, as in [1- 4]. However, on systems where photovoltaic panels and battery banks are required, at last two conversion stages are necessary [5-6]. On this way, this paper presents a non-isolated DC-DC converter integrating in a single stage a battery charger, photovoltaic panels, and a soft-switching high voltage gain boost converter. The proposed topology aims to reduce the number of conversion stages, increasing the converter efficiency, and simplifying the system control as a whole, suppressing the necessity of a individual control for each conversion stage. II. PROPOSED TOPOLOGY Figure 1 presents the proposed structure of the high voltage gain boost converter, where it can be noticed the use of voltage multiplier cells cascaded with the battery bank and the photovoltaic panels. This structure works with soft- switching characteristic, in ZVS mode on the turn-on, and ZCS and ZVS on the turn-off operation for the switch S1, and in ZVS mode for the switch S2. This converter is also capable of operating on the whore duty cycle range, without any restrictions. The proposed topology was conceived from the concept of voltage multiplier cells [7-10], which allows higher voltage step-ups, as they are cascaded: the more the number of the associated cells, the higher the voltage gain obtained for a fixed duty cycle. However, if a large number of multiplier cells, the losses will be higher, depending on the arrangement, as there are losses associated to each unit, independently. Figure 1. Proposed topology. Figure 2 presents the multiplier cell type used on the prototype. III. OPERATION PRINCIPLE The proposed converter presents eight operation stage, visualized on figures below. The topology is composed by an input inductor (L IN ), power switches (S1 and S2), transfer and rectifier diodes (D1~D6), current limiter inductor (L K ), and capacitors for storage and filter (C1~C5). Figure 4 presents the theoretical waveforms.