Torque Pulsation Minimization in a Variable Speed Inverter-Fed Induction Motor Drive System

When supplied from conventional three phase inverters, three phase squirrel cage induction motors exhibit harmonic pulsating components of torque. These torque pulsations attain objectionable values during low frequency and in many cases dictate the satisfactory lower limit of speed range. In applications requiring uniform speed of rotation these pulsating torques need to be minimized. This paper presents the results of minimizing the sixth harmonic pulsating torque component in an inverte induction motor drive system using a modified version of Rosenbrock's hill-climb technique. The optimized machine has satisfactory performance over the entire frequency range.