A Novel Speed-Sensorless Wireless Universal Motor With Bidirectional Movement

This article proposes a novel wireless universal motor. By eliminating the motor controller and position sensor, the secondary side is very simple and robust. Besides, bidirectional movement can be achieved. The key is to employ a self-driving circuit at the secondary side. Also, the advantages of the small size and large starting torque of universal motors can be retained. Hence, the proposed wireless universal motor is very suitable to be sealed and employed in isolated environments, such as pipeline pigging. A series of simulations and experiments have been conducted, which confirms that the secondary side can be self-driven, and the motor speed can be detected at the primary side.