A method for determining ipm motor parameters from simple torque test data

This paper outlines a method for obtaining the parameters for the torque constant and the D-Q axes inductances, L_d and L_q for a brushless internal permanent magnet motor (IPM) by measurement of the static torque during testing. These are relatively simple tests to carry out. A review is made of the current theory. The new theory is full described and is based on well-known standard analysis. Simulations are carried out to test the theory against results obtained elsewhere. Good results are obtained. The advantage of this is that no detailed analysis is required and loading effects can be taken into account because L_d and L_q are not constant. The example machine used is a deeply embedded split-phase IPM with variable L_d and L_q.