3-D SVM for Three-Phase Open-End Winding Drives With Common DC Bus

Abstract

Existing modulation strategies for three-phase open-end winding drives (OWDs) with common dc bus usually conduct the modulations for α-β subspace and zero-sequence loop (ZSL) separately, which cannot reflect the relationship between α-β subspace and ZSL and fully utilize the dc bus voltage. To this end, this paper proposes a three-dimensional space vector modulation (3-D SVM) strategy for three-phase OWDs with common dc bus, which can be conducted in both a-b-c and α-β- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</i> coordinates, leading to full utilization of dc bus voltage and convenient overmodulation adjustment. Voltage vector distributions of OWD in the 3-D spaces with a-b-c and α-β- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</i> coordinates are revealed at first. Subsequently, the three adjacent voltage vectors for reference voltage vector synthesis are selected based on the relationship between leg-voltage potentials, avoiding the complex tetrahedron identification in existing 3-D SVMs for other drive topologies. In addition, overmodulation in different coordinates is also investigated. Experimental results are presented to validate the feasibility of the proposed 3-D SVM for OWDs with common dc bus.