Modeling and control of an anti rotational back to back dual PMSMs for electric propulsion systems

Nowadays anti-rotational dual rotor motors are very popular in electric propulsion. These motors with single motor structure and two output shafts have better advantages like lower weight and volume, higher efficiency and better performance in comparison with conventional motors. These kinds of motors have some mechanical and cooling problems that limit their high power applications. This paper proposes a propulsion motor with two PMSMs and back to back structure and concentrating on speed and torque control of the motor. This motor has inner and outer shafts that each one is derived by an independent PMSM. Each shaft can drive an independent load like wheels or propellers. This structure can be used in electrical vehicle and marine propulsion as motor and wind and hydro turbine as generator. This paper introduces the principal and structure of the motor and derives the mathematical and simulation models. Against anti rotational dual rotor motor, a back to back structure is not anti rotational by itself; so for solving this problem, an original method is proposed. The simulation results verify the validity of resulting model and the proposed control method.