Wireless Motors – A New Breed of Power Electronics Drives

To wire, or not to wire, that is the question: Whether electric motors should go wireless. The pros and cons of wireless motors will be introduced, hence identifying the conflict and tradeoff between system reliability, transmission efficiency, electrical safety and working environment. Differing from the pseudo-wireless version which is actually a cascaded combination of the wireless power transfer system and the motor, the wireless motors should not involve any batteries, controllers or communication devices at the motor side, while performing speed control at the transmitter side. Three key types of wireless motor technology are presented, namely the wireless DC motors, wireless AC motors and wireless switched reluctance (SR) motors. Their potential applications are also discussed, with emphasis on those desiring high flexibility, electrocution-free and applicable in totally sealed or isolated environment. Meanwhile, a specially designed position sensor for wireless motors, dubbed as the wireless resolver, is introduced, which can provide timely and accurate rotor position to the primary controller. Finally, research opportunities and technological challenges of this new breed of power electronics drives are revealed.