【作者】 余腾伟；

【导师】 王旭东；

【作者基本信息】 哈尔滨理工大学 ， 电力电子与电力传动， 2007， 硕士

【摘要】 电子技术,尤其是电力电子技术的应用及其快速发展使得电力电子线路的电磁干扰(EMI,Electromagnetic Interference)问题日益突出,尤其是采用了高速半导体开关器件,如IGBT,MOSFET等,这些半导体开关产生的高频脉冲信号具有很大的dv/dt,di/dt,形成很强的电磁干扰,其频率可从几kHz直到数十MHz,有可能远远超出EMC标准要求的限值。本文分析了无源元件的高频特性,通过对电阻、电感、电容和导线的高频特性分析,可以看出,实际电阻都具有一定的杂散电感和寄生电容;而电感由于存在匝间、层间分布电容使得它不能有效地滤除高频噪声;实际电容的种类很多,由于其高频特性的不同而适用于不同的场合,电解电容由于电容量大适用于减小整流电路的纹波,而高频电容(如陶瓷电容)由于高频特性好而适用于滤除高频噪声,实际应用中要尽量减小电容的引线以减小高频寄生参数。导线也存在一定的高频寄生电感和电容,说明了在设计电力电子线路时应谨慎选择常用的无源器件。本文阐述了电磁干扰产生的机理,通过对电力电子线路工作的过程,尤其是采用的功率开关器件的特性进行分析,那么对不同的干扰可以采取相应的手段来抑制或者消除。而接地技术、屏蔽技术、滤波技术和PCB设计技术是抑制EMI最根本的技术手段,根据不同的场合选用其中的一种技术或多种技术组合,以达到抑制EMI的目的。本文针对汽车电子装置中无级变速箱控制单元(Transmission Control Unit,TCU)的驱动电路和电源电路做了较为详细的电磁干扰EMI分析,通过实验测试出干扰波形,并提出了相应的抑制措施,然后从时域和频域两方面验证了所采用措施的正确性和合理性。更多还原

【Abstract】 With the application and development of electronic technology, especially power electronics, EMI (Electromagnetic Interference) issues of electric circuits become more and more serious, especially application of fast semiconduct switching devices such as IGBT, MOSFET etc, which would produce HF pulses, then followed by large dv/dt and di/dt, and they are the essencial EMI sources. And may produce large EMI from several kilo to several million hertz frequency and the electromagnetic compatibility (EMC) standard is not submitted.HF characteristics of passive components are analysed in this thesis. Based on the analysis on HFcharacteristics of such passive components as resisters, inductors and capacitors, we may see that, practical resisters have stray inductances; inductors couldn’t filter HF noises efficiently because of distributing capacitor between circles or layers; there are many kinds of capacitors, they are used in different situations according to their HF characteristics: electrolytical capacitors are fit for minishing ripples in rectify-circuits as a result of their large capacity, while HF ones are suitable for filtering HF noises due to their nice HF characteristics. What’s more, in order to reduce HF parasitical parameters, we should make sure down-leads of capacitors are as short as possible while in practical circuits. Besides, leads have some HF parasitical inductance and capacitance. Consequently, we must choose passive components carefully.The mechanism of EMI is explained, based on analysis about working procedure of power electric circuits, especially about characteristics of power switching devices, different methods should be taken out to restrain or decrease EMI. And the following are primary solutions to restrain EMI, such as grounding, shielding, filtering, and PCB design etc. One or combination of them may be applied on the basis of different situations.EMI issues on driving parts and powers sections of TCU (Transmission Control Unit) controller are analyzed in detail. Interference waveforms were collected by means of experiments, then some solutions on rejecting electromagnetic interference are proposed, Evenmore, experiments had done to verify their correctness and rationality on aspects of both time-domain and frequency-domain.更多还原