Suppression of electromagnetic interference of low voltage auxiliary power in servo driver system
                                                                         SUN Chao, CHEN Henglin
                            (College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)

Abstract: Aiming at the inverter module in the servo drive which causes serious electromagnetic interference on the lowvoltage auxiliary power cable, the main interference propagation path was analyzed.The complex drive system was simplified, and the highfrequency commonmode circuit model of servo driver was established in Matlab simulation software. The main disturbance loop in the drive where highvoltage side interference propagates to the lowvoltage auxiliary supply was determined, by a set of drive chassis and motor chassis in different grounding conditions for auxiliary power electromagnetic interference test. Based on this interference propagation path, the interference loop was optimized, the part of the transformer in the switching power supply was optimized and the loop impedance was increased, thus greatly reducing the interference on the lowvoltage bus. The results indicate that the model is accurate and the way of suppression can significantly reduce the electromagnetic interference on the auxiliary power line.

Key words: servo drive; electromagnetic interference; lowvoltage line