LC filter design method for pulse width modulated inverter Fed induction motor drive

Abstract

High voltage stress, harmonic as well as subharmonic distortions are observed in the pulse width modulated voltage source inverter fed squirrel cage induction motor drive. It result losses in the motor, damages the winding insulation, and create electromagnetic interferences etc. As a result, it reduces the efficiency of the motor drive and shortens the life of the motor. Generally, sinusoidal LC filters are placed in between the inverter and the induction motor to smoothen the nonsinusoidal waveform to address these issues. This paper proposes a new method of designing sinusoidal LC filter based on the filter, inductor ripple current and the reactive power compensation of the induction, which basically reduces the voltampere rating of the inverter and effectively improve the overall efficiency of the drive. The newly designed filter and the filters designed by the standard methods, have been tested with the rotor flux oriented controlled induction motor and its performance have been compared.