Modeling and Performance Analysis of a Dual-Stator Brushless Doubly Fed Induction Machine Based on Spiral Vector Theory

A detailed spiral vector model of the dual-stator brushless doubly fed induction machine is developed, which unifies the steady-state and dynamic analysis into a single-phase basis through introducing complex exponential variables. The modeling method is generalized to well apply to any ac machine with arbitrary winding layout. To validate the effectiveness of the proposed spiral vector model, steady-state characteristics are predicted based on the proposed model and experimentally demonstrated under all possible operation modes, namely, simple induction, cascaded induction, doubly fed synchronous, and double-cascaded induction. The dynamic performance under open-loop operation and closed-loop control is simulated, which is followed by experimental verifications.