Active Magnetic Gear Based on a Dual-Rotor Switched Reluctance Machine

This paper presents a dual-rotor switched reluctance machine with a common stator which is able to operate as an active magnetic gear. Compared to conventional magnetic gears, the proposed machine is able to contra-rotate making the input rotor reversible. Since the machine is actively controlled, it can also be switched off which is beneficial for overload protection. The two rotors have a different amount of pole pairs which causes them to rotate a different speeds for the same stator excitation. A design method based on the torque maps obtained from finite element analysis is proposed to balance the torque production of the two rotors. Different gear ratios are investigated and their torque density is compared. A control scheme is presented to control the position of the output rotor relative to the input rotor. Simulation results are given for constant speed operation of the input rotor.