A comparison of switched doubly-fed machine drive topologies for high power applications

Doubly-fed machines (DFM) offer exciting possibilities for reducing power electronics requirements for variable speed drives (VSD). Design options are most versatile when the VSD DFM can be reconfigured "on-the-fly" in different winding and power connections. This paper presents a comparison of two different topologies of switched-DFM drives based on steady-state considerations. Effects of required drive torque, operating stator flux magnitude, and the machine parameters on the sizing of the rotor converter and on the drive performance for each of the topologies are analyzed and compared. The paper presents a holistic comparison of the two topologies to permit selection for particular application-specific requirements.