Carrier Signal Based Sensorless Control of Wound Field Synchronous Machines Using the Rotor Winding as the Receiver: Rotating vs. Alternating Carrier

Due to the accessible rotor winding wound field synchronous machines (electrically excited synchronous machines) enable a large variety of carrier signal based approaches for sensorless control. For certain machines the best suited strategy is to use the rotor winding as the receiver of the carrier signal. Regarding this transmission direction, only alternating carrier signals were investigated in detail up to now. This paper presents a new way to directly compute the rotor position using a rotating carrier signal. Moreover the impact of cross saturation and resistive voltage drops is investigated for both carrier signals. The analytical outcomes are verified by identified parameters and experimental results with a highly utilized traction motor.