Contactless Power Transfer to Shaft-Mounted Loads via Multiphase Induction Machine With Decoupled Torque and Rotor Power Control

Abstract

Contactless power transfer to rotating shaft-mounted loads represents an innovative technology with significant potential in various automation systems, such as bottling and rotary ultrasonic machining applications. These systems typically employ rotating platforms equipped with actuators and sensors that require a stable electrical power supply. Traditional solutions such as slip rings suffer from maintenance issues, leading to the need for alternative approaches. This article introduces a novel multiphase induction machine-based drive system, which incorporates an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i>-phase stator winding and two rotor windings: a three-phase propulsion winding and an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i>-phase transformer winding. The proposed system combines a propulsion motor and a rotating transformer within a single machine core to both drive the rotor and supply power to shaft-mounted loads. The system utilizes airgap field harmonics to enable both torque production and contactless power transfer to rotor-mounted electric loads using a single <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i>-phase inverter. Crucially, power regulation for the rotor electric loads is achieved through a rotor voltage observer, eliminating the need for direct access to the rotor circuit or additional hardware. An experimental setup has been developed to validate the proposed drive system's performance.