A Fast, Decentralized, Self-Aligned Carrier Method for Multicellular Converters

Quoc Dung Phan,Guillaume Gateau,Huu Phuc To,Lucas Veit,M.Mannes Hillesheim,Bao Anh Nguyen,Romain De Milly,Marc Cousineau,Phu Cong Nguyen

doi:10.3390/app11010137

Abstract

This paper proposes a fast, decentralized method for self-aligning the carriers of a multiphase/multilevel converter operating on the basis of phase-shifted pulse width modulation or level-shifted pulse width modulation. In the proposed method, each cell of the converter synchronizes and updates simultaneously its own carrier angle or carrier level based on the information shared with its neighboring cell, such as its angle/level, its index number, and the total number of activated cells of the converter. Different from the conventional decentralized method (with basic and modified updating rules), which requires some conditions in terms of cell number and initial carrier angles to start up and operate properly, the proposed method can be applied to the system with any number of cells and does not require special conditions of initial carrier angles. Further, while the conventional method needs an iteration process to adjust the inter-carrier phase-shifts and can be applied only to a multiphase converter which uses phase-shifted pulse width modulation, the proposed method offers an accurate and fast alignment of phases (for phase-shifted pulse width modulation) or levels (for level-shifted pulse width modulation) and thus can be applied to both multiphase and multilevel converter types. The simulations and the experimental results are presented in detail to show the validity and the effectiveness of the proposed methods. Further, thorough simulations on multiphase converters with different number of cells also show that the proposed method is much faster than the conventional method in both configuration and reconfiguration processes, especially in case the system has a large number of cells.

Highlights

In recent years, the studies of multicellular converters built with parallel or serial switching-cells have been intensively developed [1,2,3,4,5,6,7]
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Summary

Introduction

The studies of multicellular converters built with parallel or serial switching-cells have been intensively developed [1,2,3,4,5,6,7]. These topologies allow managing high voltage or high current outputs whilst using low voltage and low current rating switches. They can help to achieve high efficiency improvement with low harmonic distortion and can minimize the size and the volume of external passive filters. The switching-cells can be connected in parallel in a multiphase converter (Figure 1a) to increase its current output and to reduce the output current ripple [1,2] or in series in a multilevel converter

Methods

Results

Conclusion