穿通(PT)型和非穿通(NPT)型IGBT中准饱和效应的解析化分析

Analytical analysis of Quasi-Saturation Effect in PT and NPT IGBT

在绝缘栅双极晶体管(IGBT)的开通过程中,从断态到通态(即饱和态)的过程中要经过一个准饱和区。因为结的准饱和状态而增加的压降与直流线电压几乎没有任何关系。尽管该压降值比直流线电压小得多,但是因为对于高压快速IGB了来说,其时间常数相当大,所以造成的损耗也比较大。标准的零电流开关(ZCS)或零电压开关(ZVS)电路不能避免这些损耗。我们将对穿通(PT)型和非穿通(NPT)型IGBT在电感负载硬开关时的电压尾部进行仔细分析。解析化的结果将与2D(维)模拟及测量的结果进行对比,并进一步探讨电压拖尾与结附近掺杂分布的关系。为了使电感和变压器的体积和重量最小化,就必须提高开关频率。这一点对于高电压尤其重要。下面表明当开关频率超过数千赫兹时,通态压降将不再是静态时的值,通态损耗也将比所预想之值大出许多。

During the turn-on process insulated gate bipolar transistors (IGBT) traverse a quasi-saturation region from the off-state to the on-state (saturation). The additional voltage drop due to the quasi-saturation of the junction hardly depends on the DC-link voltage. Even if this voltage drop is low comparing to the DC link voltage, the losses due to this effect are rather big as its time constant is large for high-voltage high-speed IGBT. Standard ZCS or ZVS circuits canthelp to avoid those losses. The voltage...