Performance Research On Six-phase Induction Machine Driven By Trapezoidal Phase Current Waveform

With the development of power electronics and control theory, power inverter canprovide not only the three-phase power but aslo multiphase power. Multiphase machinesystem has been applied in the field of power drives. It has high reliability, low-voltagepower devices achieve high-power transmission and high efficiency, but the controlmethod is too complicated. Six-phase induction machine has been researched byMatlab/Simulink and MagNet software in electromagnetic torque, speed, efficiency.Firstly, control theory of six-phase induction machine driven by trapezoidal phasecurrent waveform has introduced. Magnetic field intensity distribution andelectromagnetic torque have been analyzed. Secondly, the finite element model ofsix-phase induction machine is established in MagNet software. It is analyzed betweenthe relationship of field current and field excitation, field current and rotor inducedcurrent, torque current and rotor induced current. Furthermore, the performance ofelectromagnetic torque and efficiency is analyzed under the equal effective value of sineand trapezoidal phase current waveform. The results show six-phase induction machinedriven by trapezoidal phase current waveform has better electromagnetic torque andhigher efficiency than sine current. Finally, co-simulation model of six-phase inductionmachine is established to fully reflect the dynamic performance in Matlab/Simulink andMagNet. The finite element machine model has replaced the traditional mathematicalmodel, avoiding the error of traditional motor model. Simulation result shows that thecontrol mode using trapezoidal phase current waveform imitates the DC machinecontrol to complete field and torque separated control.