Analysis of a novel stator winding structure minimizing harmonic current and torque ripple for dual six-step converter-fed high power AC machines

The authors study the causes of degraded converter current when dual six-step power converters feed a dual winding induction machine drive. They proposed an end winding structure and corresponding control strategy to solve the converter current problem while retaining the advantages of the dual winding induction machine drive. Principles associated with the stator winding are discussed, and a practical implementation is presented. Computer simulation is used to verify the theoretical analysis. High power, high performance AC machine drives can be achieved by using the proposed dual winding, dual six-step converter configuration. The mutual inductance plays a critical role in improving the performance of the entire system, including the machine as well as the converters. The mutual inductance is realized by the integrated machine design with the proposed winding structure. Compared to the interphase inductance, the cost of the implementation is minimum and the performance is improved