发射极开关晶闸管（EST）的仿真与研究

发布时间：2018-06-06 05:45

本文选题：功率器件 + IGBT　；参考：《电子科技大学》2016年硕士论文

【摘要】：电能的合理分配和利用对建设环保节约型社会越来越重要。电能的转换利用离不开电力电子技术。功率器件作为该技术的核心部件每次的推陈出新,都带动着电力电子技术的进步。本文研究的EST(Emitter Switched Thyristor)正是在IGBT(Insulated Gate Bipolar Transistor)的基础上提出来的一种新型功率器件。众所周知IGBT是MOS控制的晶体管结构,在其内部寄生的晶闸管未达到闩锁之前,基区由于双极性器件的电导调制效应,相同电流密度情况下,导通压降较同等掺杂水平的VDMOS器件降低了很多。然而在高压大电流的应用中,IGBT的导通电阻仍然较大,电流密度也会因此受到限制。晶闸管导通后具有很大的电流密度,低的导通压降较晶体管会有更好的正向导通特性。EST正是利用了晶闸管开启过程中的优良特性同时利用MOSFET对其导通后的特性加以控制。因此与IGBT比较而言,EST导通电阻更低,且由于MOSFET的引入其导通电流具有饱和特性,这是MOS控制型晶闸管(MCT)所不具备的。目前针对EST的研究还比较少,本文从晶闸管入手,逐步探讨关于EST及其改进器件的特性。主要内容为:1.在MATLAB中对碰撞电离积分与PN结外加反向电压的关系运用曲线拟合,得到了与MEDICI仿真结果更为吻合的Miller关系式。同时给出了掺杂浓度与Miller公式中的S参数的经验表达式。这对EST的阻断状态下的耐压设计有一定的借鉴意义。2.晶闸管特性的研究,主要内容包括:阻断状态和转折之后内部载流子的变化、电离率积分随外加电压的变化等。并应用MATLAB对其进行理论上的计算,得到其耐压的原因。EST正是对晶闸管的开启关断进行控制,因此晶闸管的研究是EST研究的基础。3.使用MEDICI软件定义EST器件结构,对其载流子分布、阈值电压、击穿电压、动态特性等进行仿真,提出了EST正向工作时的四个区域,并对不同区域进行解析分析,进而对其开关特性进行了仿真研究。4.对ESTD(Emitter Switched Thyristor With Diverter)及EST进行对比研究,对其存在的问题进行探讨,总结仿真所得结果。确定其对应的关键参数,得出优化设计的一般方法。
[Abstract]:The rational distribution and utilization of electric energy is becoming more and more important to the construction of an environmentally friendly and economical society. The conversion and utilization of electric energy can not be separated from power electronics technology. As the core component of this technology, power device brings forward the progress of power electronics technology every time. EST(Emitter Switched Thyristoris is a new power device based on IGBT(Insulated Gate Bipolar Transistor). It is well known that IGBT is a transistor structure controlled by MOS. Before the parasitic thyristor reaches the latch inside, the base region has the same current density due to the conductance modulation effect of bipolar devices. The on-voltage drop is much lower than that of VDMOS devices with the same doping level. However, in the application of high voltage and high current, the on-resistance of IGBT is still large, and the current density will be limited. The thyristor has a high current density after switching on, and the lower on-voltage drop will have better forward conduction characteristics than the transistor. EST makes use of the excellent characteristics in the thyristor opening process and uses MOSFET to control the on-on characteristics of the thyristor. Therefore, compared with IGBT, the on-resistance of MOSFET is lower, and the on-current of MOSFET is saturated, which is not available in MOS controlled thyristor. At present, there are few researches on EST. In this paper, the characteristics of EST and its improved devices are discussed step by step from thyristor. The main content is: 1. The relationship between collision ionization integral and applied reverse voltage of PN junction is fitted by curve fitting in MATLAB, and a Miller relation is obtained, which is more consistent with the result of MEDICI simulation. The empirical expressions of the doping concentration and the S parameter in the Miller formula are also given. This is useful for the design of EST. 2. 2. The main contents of the study of thyristor characteristics include the variation of internal carriers after blocking state and turning point, the variation of ionization rate integral with applied voltage, and so on. The MATLAB is used to calculate it theoretically, and the reason of its voltage resistance is obtained. EST is the control of thyristor opening and turning off, so the study of thyristor is the foundation of EST research. The structure of EST device is defined by MEDICI software. The carrier distribution, threshold voltage, breakdown voltage and dynamic characteristics are simulated. Four regions of EST forward operation are proposed, and different regions are analytically analyzed. Then the switching characteristics of the simulation. 4. The ESTD(Emitter Switched Thyristor With Diverter) and EST are compared, the existing problems are discussed, and the simulation results are summarized. The corresponding key parameters are determined and the general method of optimization design is obtained.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN34

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