A simple control technique for three-phase four-leg inverters

The paper takes into consideration three-phase four-leg inverters used to supply unbalanced loads without using a transformer. In literature different three-dimensional modulation techniques, requiring complex mathematical algorithms are proposed for this kind of inverter. The paper suggests a different approach, based on the separation of the control of the fourth leg from that of the other phases, allowing the application to the three inverter phases of traditional SVM techniques and avoiding the employment of complex procedures