Dead Zone Compensation In Digital Vector Control Of Ac Induction Motor

In electric vehicles, dead-time which is inserted in SVPWM signals of VSI distorts the inverter output voltage and current waveforms and deteriorates the control performance of an induction motor by producing torque ripples. In this paper, the IM vector control system is studied. Based on SVPWM, dead-time compensation method is implemented by calculating the angle of phase current and the magnitude of error voltage. The proposed method is only software intensive and easy to realize without additional hardware. The dead-time compensation strategy is also easy to realize in the real-time control system without increase of control cost. The results show that the motor's output torque and output power increase by using the method. The harmonics of current and voltage are also decreased with the dead-time compensation. The control strategy is verified by experiments carried on a 1.5kW IM. The experiment results show the validity and effectiveness of the proposed method.