【作者】 冯超；

【导师】 李虹；

【作者基本信息】 北京交通大学 ， 电气工程， 2019， 硕士

【摘要】 四象限变流器是列车重要的电磁干扰源,对四象限变流器进行电磁干扰建模从而为其电磁兼容设计提供指导具有重要意义。目前常采用的屏蔽、滤波、磁环等被动抑制手段会给系统增加体积、重量和成本,如果能从电磁干扰的源头入手对电磁干扰进行主动抑制,可以减小被动抑制手段给系统带来的负面影响。基于上述情况,本文开展对四象限变流器电磁干扰建模及主动抑制方法的研究。首先,本文对四象限变流器的电磁干扰源和干扰耦合通路进行了建模和分析,通过对比在小功率实验平台实测的电磁干扰频谱和基于电磁干扰模型仿真得到的频谱验证了本文所建立的电磁干扰模型的正确性。接着,针对目前电磁兼容仿真中缺乏磁环模型的现状提出一种磁环模型及其参数计算方法,利用所提模型和参数确定方法对实际磁环进行建模,并将所建磁环模型应用到四象限变流器的电磁干扰仿真中,模型对实际磁环阻抗的拟合结果以及在四象限变流器中的仿真结果证明了所建模型以及参数确定方法的正确性;然后,针对四象限变流器低频段电磁干扰,基于扩频PWM技术进行主动抑制方法的研究,分别将三角周期扩频PWM和混沌扩频PWM两种扩频PWM技术应用到四象限变流器中,在仿真中研究两种扩频PWM技术对电磁干扰的抑制作用,对比不同扩频技术、不同扩频宽度抑制效果的不同,并分析对四象限变流器输出电压的影响。此外,随着SiC MOSFET在牵引系统越来越广泛的研究和应用,本文针对SiC MOSFET在应用过程中由于开关过程电压电流尖峰和振荡带来的高频电磁干扰问题,在分析了开关过程以及电压电流尖峰和振荡产生机理的基础上,设计了一种有源驱动电路,并在实验中验证了提出的有源驱动电路对SiC MOSFET开关过程电压电流的尖峰振荡以及高频电磁干扰的抑制作用。更多还原

【Abstract】 The four quadrant converter is an important electromagnetic interference source for the train.It is of great significance to model the electromagnetic interference of the traction converter to provide guidance for its electromagnetic compatibility design.At present,the passive suppression methods such as shielding and filtering will increase the volume,weight and cost of the system.If the electromagnetic interference can be actively suppressed from the source of electromagnetic interference,the negative impact of the passive suppression means can be alleviated.Based on the above situation,this thesis studies the electromagnetic interference modeling and active suppression methods of four quadrant converter.Firstly,this thesis models and analyzes the electromagnetic interference source and the interference coupling path of the four quadrant converter.Then,the correctness of the electromagnetic interference model established in this thesis is verified by comparing the electromagnetic interference spectrum measured on the experimental platform of the low-power four quadrant converter and the spectrum based on the electromagnetic interference model simulation.Then,this thesis proposes a ferrite choke model and its parameter determination method for the current lack of ferrite choke model in electromagnetic compatibility simulation.An actual ferrite choke is modeled by the proposed model and parameter determination method,and the ferrite choke model is applied to the electromagnetic interference simulation of the four quadrant converter.The fitting results of the model to the actual ferrite choke impedance and the simulation results in the four quadrant converter prove the correctness of the model and the parameter determination method.Then,for the low-band electromagnetic interference of the four quadrant converter,the spread-spectrum PWM technology is applied.The two kinds of spread-spectrum PWM techniques,such as periodic spread spectrum PWM and chaotic spread spectrum PWM，are applied to the four quadrant converter.In the simulation,the effects of two kinds of spread spectrum PWM techniques on electromagnetic interference are studied,The suppression effects of different spread spectrum techniques and different spread width are compared,and the influence on the output voltage of the four quadrant converter is analyzed.In addition,with the increasing research and application of SiC MOSFETs in traction systems,based on the high-frequency electromagnetic interference caused by the voltage and current spikes and oscillations of the switching process during the application of SiC MOSFET,an active driving circuit is designed based on the analysis of the switching process and the voltage and current spikes and oscillation mechanism.In the experiment,the suppression effect of the proposed active gate driver on the spike and oscillation of the voltage and current of the SiC MOSFET and the suppression of the high frequency electromagnetic interference are verified.更多还原