IGCT电磁暂态模型及损耗估算

在大功率电力电子装置的可靠性设计中,开关损耗的准确估算发挥着越来越重要的作用.结合上海50 MVA静止同步补偿器(STATCOM)试运行试验中出现的上下管发热不均衡的问题,剖析了H桥电路换流过程中各器件间的电气关系,提出了集成门板换向晶闸管(IGCT)电磁暂态模型及开关损耗计算方法.在此基础上,分析了发热不均衡的原因,并提出了改进的脉宽调制(PWM)方案.实验和仿真结果表明,该IGCT模型与实际波形接近,损耗估算方法准确,新PWM方案达到了均衡上下管发热的目的.

Electrical-magnetic Model and Power Loss Evaluation for IGCTs

Accurate switching loss evaluation is playing an increasingly important role in the reliability design of large power converters and devices. For instance, the unbalanced power loss of two switches in one arm has occurred in the operational test of 50 MVA STATCOM. In view of such a problem, this paper analyzes the electrical relations between the commutating switches, develops a new electrical magnetic model and power loss calculating method for IGCTs. With the new method, the unbalanced loss is attributed to the redundant PWM state and an improved PWM is presented. Laboratory experiment and simulation results have proved that the method can be used in the design of thermal systems and for improving the balance of power loss. The waveform given by the electrical-magnetic model is close to the actual waveform.