Variation of torque constant with armature current in brushless PM motors

This paper examines the phenomenon of armature reaction and its effect on the torque per ampere characteristic or torque constant-k/sub T/-in brushless PM motors. In order to take account of saturation, finite element analysis is used together with the flux-MMF diagram. The technique of the flux-MMF diagram makes accurate prediction of instantaneous as well as average torque in both linear and saturated electric machines. The predicted results are presented along with the experimental data for a squarewave brushless DC and a sinewave brushless AC motor.