An extendable single‐switch n‐cell boost converter with high voltage gain and low components stress for renewable energy

Abstract

Boost converters have been widely employed in industrial applications, and cascading boost converters is a mature technique to realize ultrahigh voltage gains.However, the cascade structure inevitably increases the voltage stress of buffer capacitors, resulting in high costs and low energy efficiency. Targeting this issue, in this study, we propose a novel extendable single-switch n-cell boost converter (ESSnB), which utilizes the same number of components as the conventional positive output boost converter, but has lower buffer voltage stresses. Simulation and experimentation are conducted in this study, which verify the effectiveness and superiority of the proposed ESSnB over conventional boost converters. KEYWORDS extendable multicell converter, low component stress, single-switch boost converter INTRODUCTIONHigh step-up converters have been playing an indispensable role in modern renewable energy-integrated power grid, but traditional boost converters, with a simple circuit structure and control schemes, cannot realize the high voltage gains that are required in modern renewable energy sector. [1][2][3][4][5][6] In order to achieve a high voltage gain, various high step-up converters on a single-stage basis have been proposed and applied in wide-ranging applications to realize desired voltage gains, such as clamped-inductor, 7,8 switched-capacitor, 9,10 impedance network, 11-13 switched-inductor, [14][15][16] voltage multiplier, 17,18 and magnetic coupling. 19,20 However, single-stage converters can no longer satisfy high-voltage gain requirements in current power system applications, and a common method to overcome this limitation is to implement various voltage-pumping techniques into a number of identical or different converter modules. [21][22][23] As shown in Figure 1, cascading boost converter is the simplest method to obtain a high-voltage conversion ratio. However, a larger number of converters connected in series leads to lower energy efficiency and causes difficulties in control design. 24 To solve these problems, a group of positive Int J Circ Theor Appl. 2020;48:817-831.wileyonlinelibrary.com/journal/cta

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