Control of a Three-Phase Wound-Rotor Induction Motor Drive for Automation Applications

The use of rotary assembly platforms, such as the automated box-fill system rotary table, is widespread in automation applications. One of the problems that the designers have to face is how to transfer the power to the auxiliary actuators mounted on the rotating platform. In this paper, this problem is solved by adopting a direct drive three-phase wound-rotor induction machine that can independently control the rotor torque and the power flow delivered to the rotor loads. To achieve this result, a high-frequency component is added to the air-gap magnetic field to generate an adjustable electromotive force in the rotor windings. Some experimental results are shown to confirm the feasibility of the control scheme.