Two-axis model development of cage-rotor brushless doubly-fedmachines

A two-axis model of a cage-rotor brushless doubly-fed machine (BDFM) which is suitable for machine and BDFM drive system dynamics studies is presented. The technique enables the two-axis model to be derived from a detailed model recently developed for investigation of design aspects of the machine. Unlike the conventional approaches to self-cascaded machines analysis, this method permits analysis of the machine characteristics in both dynamic and steady state conditions, and also facilitates machine and drive system design by directly correlating machine performance with machine structure and parameters. The approach allows the machine parameters to be calculated from machine geometry and developed into the model parameters