Suppression control of radial force vibration due to fundamental permanent-magnet flux in IPMSM

The relationship between electrical 2nd order radial force and dq-axis current is examined and 2nd order acceleration is suppressed in this paper. On no-load condition, flux distribution is approximated in order to calculate radial force. Radial force on a tooth is obtained by using maxwell stress equation and approximation of flux distriution. Considering cyclic nature of 3-phase, optimal d-axis current to suppress 2nd radial force which is caused by fundamental permanent flux is proposed. Simulations and experiments under load and no-load conditions are performed to show the validation of proposed optimal d-axis current reference.