Simultaneous measurement of the moment of inertia and braking torque of electric motors applying additional inertia

Abstract

This paper presents a method for the simultaneous measurement of the moment of inertia and braking torque of the rotor of electric motors. The procedure is based on retardation tests on the motor applying additional loads on its rotor with different moments of inertia but equal masses. The equal masses provide equal braking torques in the supporting bearings. Besides the detailed description of the experimental setup and method – a procedure for determining the optimal values of the loading moments of inertia is also presented. At these optimal values, the errors of the experimentally determined moment of inertia and braking torques are minimal. Additionally, the effect of the temperature change of the bearings on the accuracy and precision of the method is also analyzed and discussed. Finally, the method's experimentally validated accuracy and precision are reported, and measurement results on an induction motor are presented as an example.