The Tool for Losses Analysis of Induction Motor Fed by Conveter PWM

This paper summarizes the technical approach of losses resolution in the Induction Motor (IM) supplied by Pulse Width Modulation (PWM) of the nonharmonic deform converter voltage. The main aim is to get the total motor losses which can be separated on the fundamental harmonic component of supply voltage and higher order harmonic components represented by harmonic losses. This analysis is directly provided from measured waveform of input/output quantities such as voltage, current, torque and speed. The 55 kW/4 p motor is supplied by the converter with chosen switching frequency 2, 4 and 8 kHz with fundamental frequency 50 Hz. Further, the results are compared with other measurements on the same motor provided with sinus source which replaces the real grid (DOL – direct on line).