大功率晶闸管热阻抗分析方法的研究

随着柔性交流输电和高压直流输电设备在我国电力系统中应用越来越广泛,以晶闸管为主组成的高电压大电流电子阀等核心技术已成为研究焦点。晶闸管的结温及其变化影响晶闸管的电学特性及其使用寿命,而晶闸管的热阻抗直接影响晶闸管的结温,因此,晶闸管的传热特性及其建模方法的研究对于晶闸管及其阀的研制具有很重要的现实意义。论述了现有热阻抗分析及其建模的方法,即试验方法和数学物理方法,分别讨论了它们的建模过程及建模结果－等效热阻抗网络。提出了Foster热阻抗网络转换成Cauer热阻抗网络的"直接恒等法"以及一种通过有限元数字仿真分析晶闸管内部温度场以及求解晶闸管结壳热阻抗的方法,该方法的有效性通过了实测数据的验证。

Study on Analysis Methods of Thyristor Thermal Model

The solid state switch mainly based on thyristor becomes people's research focus with more and more flexible alternative current transmission system(FACTS)and high voltage direct current transmission(HVDC)devices applied in power grid.The thyristor junction temperature and its change, which are directly related to its thermal impedance,decide the electrical characteristics and life expectancy of thyristor. Therefore studying its heat transfer characteristic and thermal model is meaningful to the development of thyristor and its valve The analysis methods of thyristor thermal model were divided into two categories,namely the testing method and the mathematical physics method,and their modeling procedures and equivalent thermal networks respectively were discussed. One method named"directly identical to each other method"was provided to transform Foster network into Caner network.The thyristor internal temperature field was analyzed and its impedance was.calculated by f'mite element method(FEM) digital simulation.Testing results show that the method is effective.