A novel compensation method for a motor phase current sensor offset error varied during a VSI-motor drive

This paper presents a method for reducing a torque ripple resulting from a motor phase current sensor offset error for motor drive applications such as a hybrid electric vehicle. The proposed method compensates for the motor phase current sensor offset error by subtracting a motor phase current sensor offset error value estimated by using a discrete Fourier transform from a detected motor phase current value. Its main feature is its ability to compensate for the motor phase current sensor offset error that varies due to temperature change during the inverter-motor drive. Simulation results reveal that the proposed method can estimate the motor phase current sensor offset error with less than or equal to +-2[A] difference and reduce the average value of the motor torque ripple to half (1/2) of that without the proposed method in a steady state.