Practical Implementation of Sensorless Torque and Reactive Power Control of Doubly Fed Machines

A recently proposed shaft position sensorless method for torque and reactive power control of the brushless doubly fed reluctance machine has proven successful in simulation studies. In this paper, its real-time performance has been evaluated on a custom-designed machine prototype. The preliminary experimental results have confirmed the viability of the scheme and represent a serious step toward the development of a generic virtually parameter independent controller for doubly excited machines. A wide range of applications is possible, including drive and generator systems with limited speed ranges (e.g., large pumps and wind turbines), where the cost savings of using a partially rated power electronic converter are significant.