基于晶闸管的脉冲功率开关热模型研究

晶闸管作为脉冲功率开关器件时,其短时导通电流往往数倍于它的通态平均电流,短时积聚的损耗会使晶闸管结区累积大量热量,造成其结温瞬间陡升,试验表明极易使得晶闸管因结区过温而击穿.因此如何优化设计晶闸管脉冲功率开关阀体结构、最大限度快速散热、降低结区温升,具有重要意义.介绍了基于ABB的5STP 52U5200型晶闸管所构建的脉冲功率开关阀体结构及其柯尔热阻抗模型,并利用Matlab的SimuLink构建脉冲功率开关阀体的热网络仿真模型,获取晶闸管耗散功率与其最高结温、晶闸管耗散功率与其壳温的可视化关系曲线,归纳了脉冲功率开关导电极的热阻与热容对晶闸管最高结温的影响规律,为晶闸管脉冲功率开关阀体结构的优化设计提供了依据,并得到了试验验证.

Thermal Model for Pulse Power Switch Centered on Thyristor Device

The working current of the thyristor as the pulse power switching device is often several times of the average current of thyristor. The power loss can produce lots of heat for its junction at the short time, and the junction temperature will rise instantly and obviously, which will breakdown its junction region or damage the device. Therefore, it is important to optimize the cooling structure of the power pulse switch with good cooling capacity. A thermal model based on the thermal Cauer model of the 5STP 52U5200 device produced by ABB is introduced by the paper. Thermal network model of the pulse power switch is established and simulated centered on the SimuLink environment of Matlab. The relationship curves of the power loss vs. the highest junction temperature and the power loss vs. the case temperature are acquired. The thermal re sistance and heat capacity of the conductive plates have an effect on the junction and the case temperature of the thyristor. Both theoretic analysis and experimental results can verify the truth of the design method of the cooling structure of the pulse power switch centered on the thyristor device.