Investigation of conducted emissions produced by a PWM inverter-fed motor drive

This paper describes an experimental investigation of conducted noise emission produced by a pulse width modulated (PWM) inverter of low power feeding an induction motor. The investigation carried out for two types of PWM waveform generators, namely the pure sinusoidal PWM generator (MA828-2) and the sinusoidal with superimposed third harmonic PWM generator (MA828-1). Measurement of conducted EMI noise for the EUT (equipment under test) and its compliance with the regulations is presented. Then, low-cost strategies for improvement in EMC performance of the PWM inverter are proposed.