Investigation and Suppression of Conducted EMI and Shaft Voltage in Induction Motor Drive System

This paper proposes an induction motor drive system capable of suppressing shaft voltage and electromagnetic interference (EMI). A filter developed for this system is characterized by sophisticated connection of two small passive filters between inverter output and motor which can compensate for common mode voltages produced by PWM inverter and between motor neutral point and rectifier input which can suppress leakage current and EMI. As a result small passive filter with ability of reducing of EMI in mains side and shaft voltage is approached. Experimental results show the reduction characteristics of the shaft voltage, common mode voltage and EMI.