Rotor field oriented control of five-phase induction motor with the combined fundamental and third harmonic currents

This paper presents an application of rotor field oriented control (RFOC) to a five-phase induction motor with the combined fundamental and third harmonic currents. Based on the motor model developed in a new d(1)q(1)d(3)q(3)n reference frame, the complete theory and modeling of rotor field oriented control of the five-phase induction motor are established. Specifically, investigation is made to improve power density and output torque of the five-phase induction motor by injecting third harmonic of currents. By the proper dynamical adjustment and steady state compensation, the rotor field oriented control of the five-phase induction motor not only achieves a high drive performance, but also controls the fundamental and third harmonic flux and torque to generate the desired nearly rectangular air-gap flux. Both simulation and experimental results further verify the theoretical analysis and demonstrate the feasibility and practical value of the proposed five-phase induction motor drive.