Stability Analysis of a Brushless Doubly-Fed Machine under Closed Loop Scalar Current Control

This paper presents a stability analysis of the brushless doubly-fed machine (BDFM) under closed loop scalar current control (CLSCC). The recently developed unified reference-frame dq model leads to an invariant small signal model reflecting the dynamic of the BDFM under CLSCC. Theoretical stability analysis shows a stable behavior along all the operation range. This result is confirmed by an experimental BDFM set-up. It is concluded that CLSCC becomes the simplest control alternative of any real BDFM application