本文選題：脈沖功率　切入點：反向開關(guān)晶體管　出處：《華中科技大學》2015年碩士論文

【摘要】：現(xiàn)代脈沖功率技術(shù)的發(fā)展越來越要求較高的運行頻率,來滿足其在國防、工業(yè)、醫(yī)療及環(huán)保領(lǐng)域的應(yīng)用。作為系統(tǒng)中關(guān)鍵技術(shù)的開關(guān)器件,就更加注重低損耗、大功率、高重復頻率和長壽命等器件特性。相比于其他器件,反向開關(guān)晶體管(Reversely Switched Dynistor,簡稱RSD)因采用可控等離子體層換流開通原理而具有均壓特性好、通流能力強和較高電流上升率等性能,能較好滿足脈沖功率技術(shù)對功率開關(guān)器件的要求�；赗SD的等離子體雙極漂移模型得到的開通電壓表達式,可以看出RSD開通時具有較高電壓峰值,對脈沖功率系統(tǒng)是不利的。文章分別從Si RSD結(jié)構(gòu)優(yōu)化和采用新材料(4H-SiC)制作器件兩個方面著手,研究如何降低系統(tǒng)中RSD器件的開通損耗。研究單只Si RSD器件的開通電壓與阻斷電壓關(guān)系時,實驗電路中選取耐壓為0.8kV RSD器件和耐壓為2.5kV RSD器件進行對比實驗,結(jié)果表明在相同電壓放電下前者最大開通電壓顯著低于后者。同時,向RSD引入緩沖層來優(yōu)化器件結(jié)構(gòu)參數(shù)進而改善器件的開關(guān)特性。采用正交試驗設(shè)計的方法來評估不同參數(shù)緩沖層結(jié)構(gòu),并選出最優(yōu)組合。實驗對比了耐壓2.5kV RSD,結(jié)果表明同等條件下帶緩沖層結(jié)構(gòu)的開通損耗比傳統(tǒng)結(jié)構(gòu)降低了18.96%。在新結(jié)構(gòu)優(yōu)化特性的基礎(chǔ)上,嘗試從更基礎(chǔ)的新材料進行優(yōu)化。首次提出采用第三代寬禁帶半導體材料Si C代替Si制作RSD器件,并建立數(shù)值模型進行具體的仿真研究。采用4H-SiC材料各物理量經(jīng)驗參數(shù)值,考慮大注入條件下的典型物理效應(yīng),并結(jié)合外電路模型對SiC RSD的斷態(tài)和通態(tài)特性進行模擬仿真。仿真數(shù)據(jù)表明在同等高阻斷電壓下,Si C RSD比Si RSD具有更好的開通特性。
[Abstract]:The development of modern pulse power technology requires higher operating frequency to meet its application in the fields of national defense, industry, medical treatment and environmental protection. As a key technology in the system, switching devices pay more attention to low loss and high power. Compared with other devices, the reverse switching transistor Reversely Switched Dynistor (RSDs) has the characteristics of uniform voltage due to the controllable plasma layer commutation switching principle. The characteristics of high current passing ability and high current rising rate can meet the requirements of pulse power technology for power switch devices. The on-off voltage expression based on RSD's plasma bipolar drift model is obtained. It can be seen that RSD has a high peak voltage when it is turned on, which is disadvantageous to the pulse power system. This paper starts from two aspects: the structure optimization of Si RSD and the fabrication of devices with new material 4H-SiC. This paper studies how to reduce the switching loss of RSD devices in the system. When studying the relationship between the on-off voltage and the blocking voltage of a single Si RSD device, the experimental circuit selects the voltage-proof device as 0.8kV RSD device and the voltage-proof device as 2.5kV RSD device to carry on the comparative experiment. The results show that the maximum turn-on voltage of the former is significantly lower than that of the latter under the same voltage discharge. The buffer layer is introduced to RSD to optimize the structure parameters of the device and improve the switching characteristics of the device. The orthogonal design method is used to evaluate the structure of the buffer layer with different parameters. The results show that the switching loss of the structure with buffer layer is 18.96 less than that of the traditional structure under the same conditions. On the basis of the optimized characteristics of the new structure, The third generation wide band gap semiconductor material sic instead of Si is used to fabricate RSD devices for the first time, and a numerical model is established for the specific simulation study. The empirical parameters of various physical quantities of 4H-SiC materials are used. Taking into account the typical physical effects under the condition of large injection, and combining the external circuit model to simulate the on-state and on-state characteristics of SiC RSD, the simulation data show that the on-off characteristics of Si C RSD are better than that of Si RSD at the same blocking voltage.
【學位授予單位】：華中科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN32

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本文編號：1686314