Minimizating Pulsating Torque in PMSM Drives by using Feedforward-based Compensation and Flux-harmonic Estimation

Acoustic noise and vibration are one of the main issues concerning permanent magnet synchronous motor (PMSM) drives. The issue occurs because PMSMs generate pulsating torque and self-excite mechanical resonance of their drive systems. To produce smooth torque, a novel control scheme using (i) feedforward-based compensation to achieve an actively oscillating current precisely and (ii) estimation of spatial harmonics included in the permanent magnet flux distribution is proposed. These functions can produce smooth torque without pre-measurement and tuning of parameters related to occurrence of pulsating torque and its compensation. Moreover, they use simpler algorithms than existing ones. It is therefore possible to implement them on a drive platform for mass-produced products such as fans and pumps. The effectiveness of the proposed control scheme was verified by simulation and experimental tests on a PMSM for an air-conditioning fan.