Title: Multilevel inverter for grid interconnection with square wave voltage sources and minimisation of active filter capacity

Authors: Yuichi Noge; Mingcong Deng; Mitsuru Miyashita

Addresses: Faculty of Information Science and Electrical Engineering, Kyushu University, 744, Moto-oka, Nishi-ku, Fukuoka City, Fukuoka, Japan ' Department of Electrical and Electronic Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo, Japan ' Department of Electrical and Electronic Engineering, Nagaoka University of Technology, 1608-1 Kamitomioka, Nagaoka, Niigata, Japan

Abstract: This paper proposes an integrated micro-inverter using a multiple-step controlled voltage source and an active filter connected in series. Recently, a micro-inverter based on an isolated resonant DC-DC converter is widely used. A typical micro-inverter can achieve a high efficiency around 97%. In addition, a micro-inverter system can achieve high efficiency of maximum power point tracking (MPPT) thanks to its small photovoltaic area. The proposed circuit is a combination of a multiple-step controlled voltage source, an active filter connected in series and an unfolding circuit. This circuit reduces the power to be converted to 1/8 compared to a conventional inverter. The control strategy for the proposed circuit is also discussed in this paper. Finally, the grid connected operation is verified through circuit simulation.

Keywords: renewable energy; photovoltaics; multi-level inverter; grid interconnection.

DOI: 10.1504/IJAMECHS.2021.119109

International Journal of Advanced Mechatronic Systems, 2021 Vol.9 No.3, pp.146 - 153

Accepted: 20 Jul 2021
Published online: 22 Nov 2021 *

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