2014 Volume 3 Issue 4 Pages 328-334
This paper proposes an optimal d-axis current to suppress the 2nd radial force, which is caused by the fundamental permanent flux. Under the no-load condition, the flux distribution is approximated in order to calculate the radial force. Considering the cyclic nature of 3-phase, the optimal d-axis current reference to suppress the 2nd radial force is derived. Simulations and experiments under both load and no-load conditions are performed to demonstrate the validity of the proposed optimal d-axis current reference.