Electromagnetic Compatibility Analysis And Design Of PWM Motor Driver

In motor driving systems, there are a lot of electromagnetic interference(EMI) problems, which will influence the stability and reliability or even bring potential risk to relating equipment. In this paper, both conduction EMI an d radiation EMI are analyzed in neutral point clamped three-level(NPC 3-Level) motor driving system, and then corresponding solutions are put forward. At last, experiments and EMC tests are conducted on the platform designed according to the EMI/EMC analysis.Except for the fundamental wave, there are influent high frequency harmonic derived from high frequency clock signal in control circuit, power semico nductors in main circuit, and the performance of non-ideal components, like parasitic inductors and capacitors. According to GJB 151B-2013 Electromagnetic emission and susceptibility requirements and measurements for military equipment and subsystems, the conduction EMI is assessed. Control strategy, capacitor in DC side, parasitic parameters, and deadtime of IGBT are the factors that will cast influence onto the conduction EMI in a PWM driving system. The character of such conduction EMI is analyzed and some helpful method are proposed, especially a design of common mode filter.On the other hand, research on radiation electromagnetic interference is conducted in the aspects of EMI source, EMI transmission and EMI receiver. At first, IGBT and DC bus are identified as the main source of radiation electromagnetic interference, thus their modes for simulation are built in ANSYS and electromagnetic field generated by them are calculated. Then we make an analysis on the radiation EMI transmission and a shelter is designed to shield radiation interference. The effect of electric and magnetic shield are also compared to standards of GJB 151B-2013 Electromagnetic emission and susceptibility requirements and measurements for military equipment and subsystems. Then the electromagnetic compatibility(EMC) of printed circuit board(PCB) is analyzed using SIwave, ANSYS. The resonant mode, near/far field radiation, and induced voltage are computed based on an existed PCB design. The results could also instruct the EMC design of a PWM driving system in return.At last, according to the analysis, an EMC design of driving system is completed, which focus especially on the signal processing, IGBT drivers, and the connection of each part in main circuits. Some experiments and te sts are conducted on the founded platform.