Modeling and analysis of a wide speed range induction motor drive based on electronic pole changing

It has been previously demonstrated that an induction machine drive with contactorless pole changing can be achieved by reversing current directions of certain stator coil groups. This paper compares power and torque capability of this with conventional four pole and two pole induction machine drives. Based on the technique of vector space decomposition the machine coupled circuit model is transformed to a reference frame model. As a result of this transformation the coupled coil group variables can be replaced by equivalent decoupled four pole and two pole dq0 variables. This reference frame model facilitates the analysis and control of the machine drive especially during transients such as the pole changing transition