A novel sensorless position and speed estimation method for heteropolar inductor machines

This paper proposes a novel position/speed estimation method for a special type of armature side excited synchronous machine, namely heteropolar inductor machines, by taking advantage of the machines´ unique structural characteristics. The field winding characteristics of heteropolar inductor machines are analyzed firstly. Analytical approaches for developing q-axis position and rotor speed estimation algorithm are then discussed, based only on terminal voltage and current measurements. Finally the validity of theories is supported by practical experiments, and the performance of estimations of position and speed under both steady state and transient conditions are shown by experiments in a prototype machine.