Current sensor offset cancellers in IPMSM vector control system

Abstract

Motor torque ripples generally produce a problem of noise and vibration. The torque ripple could be caused by an offset in the current sensor output. This paper presents that a current sensor offset leads to the 1st order harmonic component of the torque ripple to the electric angle. Moreover, the current sensor offset canceller is proposed as a countermeasure against the 1st order harmonic component. In the offset canceller, the offset value is evaluated from the 1st order harmonic components of the ripples of d, q axes currents through Fourier series integration. Then, the remote monitoring system for the current sensors can use the proposed offset canceller. The experimental and simulational results prove the efficiency of the offset canceller.