RESEARCH ARTICLE High step‐up DC‐DC converter with reduced voltage stress on devices Ebrahim Babaei 1,2 | Tohid Jalilzadeh 1 | Mehran Sabahi 1 | Mohammad Maalandish 1 | Rasoul Shalchi Alishah 1 1 Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran 2 Engineering Faculty, Near East University, 99138 Nicosia, North Cyprus, Mersin 10, Turkey Correspondence Ebrahim Babaei, Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran. Email: e‐babaei@tabrizu.ac.ir Summary The aim of this study is to propose a new nonisolated direct current (DC)–DC converter topology with high voltage gain and low voltage stress across the power devices. The proposed converter comprises a switch and n stages of inductor‐capacitor‐diode (L‐C‐D) units. Indeed, the proposed converter is based on the combination of the double‐boost and Single‐ended primary‐inductor converter (SEPIC), which is extended to n stages by adding L‐C‐D units. As a consequence, the proposed converter can generate higher voltage gains with small values of the switch duty cycle, which increase the controllability of the converter. Also, as the number of stages increases, the normalized voltage stress across the power devices is reduced. As a result, the Metal Oxide Semi- conductor Field Effect Transistor (MOSFET) switch with low R DS‐on and devices with reduced nominal voltage can be used in the proposed converter. Furthermore, another advantage of the proposed converter is that the percent- age of input current ripple is low. The voltage and current stresses of the power devices are analyzed. The circuit performance is compared with other high step‐up structures in the literature in terms of voltage gain and normalized voltage stress. The mathematical analysis and circuit performance of the pro- posed topology are verified by experimental results. KEYWORDS boost DC‐DC converter, high step‐up DC‐DC converter, low voltage stress, nonisolated converter 1 | INTRODUCTION Today, renewable energy sources are increasingly valued in industrial applications due to the shortage of fossil fuels and increasing air pollution. Photovoltaic (PV) panels are one of the most popular renewable energy generation systems, which directly convert sunlight into electricity. However, the generated voltage by PV panels is variable and low, which is related to LIST OF SYMBOLS AND ABBREVIATIONS: DC, Direct current; n, Number of stages; SEPIC, Single‐ended primary‐inductor converter; MOSFET, Metal‐oxide‐-semiconductor field‐effect transistor; R DS‐on , Drain‐source on‐state resistance; PV, Photovoltaic; MPPT, Maximum power point tracking; EMI, Electromagnetic interference; CCM, Continuous conduction mode; DCM, Discontinuous conduction mode; T, Switching period; M CCM , Voltage gain in CCM; SSA, State‐space averaging; M DCM , Voltage gain in DCM; M S , Normalized switch voltage stress; M D , Normalized diode voltage stress; M C , Normalized capacitor voltage stress; RMS, Root mean square; D, Duty cycle; V i , Input voltage; V o , Output voltage; P o , Output power; f , Switching frequency; K e,c , critical conduction parameter; L e , equivalent inductance; ESR, Equivalent series resistance Received: 17 April 2018 Revised: 28 October 2018 Accepted: 9 November 2018 DOI: 10.1002/etep.2789 Int Trans Electr Energ Syst. 2018;e2789. https://doi.org/10.1002/etep.2789 © 2018 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/etep 1 of 24