Vector Control of Double-Delta Sourced Winding for a Dual-Winding Induction Machine

Ripple currents can be mitigated in motor drives by applying double-delta sourced winding (DDSW), which uses a multilevel operation approach with two-level converters. In practice, a dual-winding induction machine (DWIM) has been considered for this application due to its inherent compatibility with DDSW. The modeling of a DDSW-based DWIM is discussed for vector control, and a decoupling method between converters is proposed to improve the dynamic response of the current regulation. In addition, torque control is discussed for a situation in which one of the converters is dropped out. The effectiveness of the proposed methods is assessed via experiments under low switching frequencies because DDSW is appropriate for high-power applications, where multiple windings are essential. It was confirmed that the total harmonic distortion of the converter currents was decreased by 67.7% when an 11-kW DWIM was driven on the basis of DDSW. Furthermore, the bandwidth of the current regulation could be increased by 113.7% owing to the proposed decoupling method.