Control of an Electric Machine Integrated With the Trans-Rotary Magnetic Gear in a Motor Drive Train

This paper studies the dynamic performance of an electric machine integrated with the transrotary magnetic gear (MITROMAG) in a motoring mode of operation. MITROMAG is formed by mechanically coupling a rotary electric machine to the rotor of a trans-rotary magnetic gear (TROMAG). TROMAG is a magnetic device that, through magnetic fields, converts a low-torque, high-speed rotation of its rotor to a high-force, low-speed linear motion of its translator, and vice versa. In a motoring mode of operation, the rotor of the TROMAG is driven by a rotary electric motor, and as a result, its translator drives a reciprocating load. A nonlinear dynamic model is developed for the TROMAG. Oscillation tests are presented as examples of how the model can be used to predict the dynamic behavior of the device. The model is then linearized to derive system transfer functions and study the dynamic response of the MITROMAG to speed commands. Experimental results confirm the analysis.