A Novel Primary-Controlled Wireless Permanent Magnet Synchronous Motor Without Position Sensor

Traditional two-stage wireless permanent magnet synchronous motor (PMSM) systems heavily rely on position sensors and wireless communication between primary and secondary sides. This introduces complexity to the motor-side system and is susceptible to performance degradation due to communication delays. In addressing these issues, this article presents a novel primary-side controlled wireless PMSM that operates without position sensors. The proposed system integrates a sensorless algorithm, unifying energy and information flow, eliminating the need for motor-side encoders or communication modules. First of all, the system features three decoupled dual-channel wireless power transmission circuits and current regulation for completely passive motor-side operation controlled by the primary side, with simultaneous transmission of power and control signals. Moreover, the system leverages constant current output characteristics to monitor changes in motor-side equivalent impedance through observation of high-frequency coil current on the primary side, enabling identification of motor position and speed information. In addition, the proposed single-loop speed control achieves unit power operation, enhancing system stability. Finally, experimental validation on an 800 r/min 2 N·m wireless motor platform demonstrates the system's effectiveness, achieving 82.6% efficiency under maximum speed and load and enabling a seamless transition from blind startup to speed feedback control.