Minimization of Resonant Frequency Oscillations in Terminal Voltages of AC Motors Using Active Damping Technique

This paper presents the detailed simulation of comparison between Induction Motor and Synchronous Motor with reduction of resonant frequency oscillations in their terminal voltages by using Active damping technique. This paper mainly concentrated on protection of Induction motor and Synchronous motor under any balanced or unbalanced load conditions and this proposed technique is simulated with the combination of Voltage Source Inverter (VSI), LC Filter and AC Drives (I.M&S.M). However, the LC-Filter created unwanted oscillations due to internal resistance at system resonant frequency. This resistance drop is emulated by controlling terminal voltage. In this paper Active damping technique is used to damp out the unwanted resonant frequency oscillations and proposed for lossless damping of vector-controlled ac drives with LC-Filter. The proposed technique neither affects the dynamic response of the drive nor changes the design of the standard vector control loops. This proposed technique is carried out in three phase domain for better accuracy of control. This paper has been implemented and simulated by using MATLAB 7.8 (R2009a) / SIMULINK version. Simulation results have been compared successfully with Induction motor and Synchronous motor in steady state, transient state and robustness conditions.