Segregation of Additional High Frequency Harmonic Losses Created by PWM Supply

Abstract

This paper describes a method for analysing high frequency harmonic losses in the rotating field machines supplied with a frequency converter. The loss segregation is mainly used in the energy efficiency classification and analysis of direct-online induction motors. Previously, there has not been a universal method to segregate the additional high frequency harmonic losses created by the PWM supply from the experimentally determined total losses of the 37-kW modern IE3 rated converter-fed induction motor. This paper demonstrates the method to segregate and analyse the high frequency harmonic losses created by the PWM supply based on the assumption that the loss component is equal to harmonic power determined from the electric power measurement from the motor terminals. The loss segregation is performed in 30 operations points in the frequency - torque plane. The drive system losses are segregated into the loss components, converter losses, motor losses, and high frequency harmonic losses.