| PMSM(Permanent magnet synchronous motor),by virtue of its high efficiency,small size,light weight,low noise,and high reliability and so on,is widely used in every field of social life.with the more complicated application environment,the requirements for permanent magnet synchronous motor driver have gradually increased.Besides satisfying the requirements of basic control and drive functions,it also needs to meet the strict electromagnetic compatibility(EMC)standards of related industries,which becomes a difficult problem of PMSM driver.Electromagnetic compatibility includes electromagnetic interference(EMI)and electromagnetic sensitivity(EMS).For PMSM drivers,the prominent problems are radiated interference and conducted interference in EMI performance.The high speed switch of power electronic device in PMSM driver produces large dv/dt and di/dt,the large number of high order harmonics brought by PWM modulation signal periodically and the nonlinearity of device and circuit will cause serious radiation interference and conduction interference.This thesis,taking the automotive electronic water pump as the carrier,explores EMI suppression technology mainly from two perspectives of radiation interference and conduction interference of PMSM driver.firstly,this thesis deeply analyzes the mechanism of EMI problems of permanent magnet synchronous motor drivers as well as the sources of radiated and conducted interference and calculates the sources of interference.Meanwhile,the propagation paths of radiated and conducted interference are investigated.Secondly,this thesis not only proposes a common mode conduction model of PMSM driver but also conducts a simulation analysis of common mode interference voltage and current.Also the effect of various parasitic parameters on the common mode EMI is studied.According to the results of model analysis,a method for suppressing common-mode conducted interference is put forward.The results produced by simulation and experiment show that this method has obvious suppression effect on common-mode conducted interference.Thirdly,for radiation interference,a new design method of absorption circuit,switching device drive circuit,DC-side capacitor filter circuit and ground circuit is proposed,which effectively suppresses the influence of radiation interference.At the same time,the influence of different space vector modulation on the radiated interference is studied.Finally,the present research builds a radiation interference test platform and tests the radiated interference performance of electronic water pumps.The findings of the test present that the serious area of PMSM driver radiation interference is mainly in the 70MHz-110 MHz frequency band.By adopting the radiation interference suppression method proposed in this thesis,the low-voltage and high-power automotive electronic water pump developed meets the electromagnetic compatibility requirements of GMW3097-2019.The results of this thesis provide significant guidance for the suppression electromagnetic interference of various PMSM drivers. |
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