Three Dimensional Space Vector Modulation for Three Phase Four Leg Inverters - A Review

This paper discusses three dimensional space vector modulation techniques (3DSVM) for three phase four leg inverters and its development over the past two decades. Three dimensional Space vector Modulation is the successor of conventional two dimensional space vector modulation (2DSVM), with an additional ability to deal unbalanced three phase system. An unbalanced three phase system demands a third dimension to represent zero sequence current in addition to conventional a and β frames. Here analysis of unbalanced three phase load system, types of three wire three phase systems, general methodology of 3DSVM, types of modulation techniques αβγ and abc coordinate system, and other new improved systems like gh γ system are discussed.