Study on Different Connection Modes of Dual-Stator Brushless Doubly-Fed Machine Based on Field-Circuit Method

The different winding connection modes of dual-stator brushless doubly-fed machine (DSBDFM) are investigated to ensure the electromagnetic characteristics consistency of outer and inner stator. The electromagnetic characteristics consistency is not only required that the electromotive force (EMF) amplitude and phase match the requirements of outer and inner stator winding connection mode, but also the number of parallel branches of winding should be considered to avoid the circular current and phase difference. This paper proposes a method for the number of parallel branches of winding, which is helpful to determine the number of parallel branches of two sets of winding with different pole pairs number in stator slots and ensure the EMF amplitude and phase of per branch winding. The field-circuit method (FCM) is used to analyze the different connection modes of DSBDFM, such as series, parallel, series and parallel. The finite element method was confirmed agreement with the FCM, indicating the validity and rationality of FCM.