微电网大功率IGCT变流器重触发问题的研究

Study of Micro Grid Power IGCT Converter Heavy Trigger Problem

随着分布式发电的容量提升,在并网设备方面需要有高压、大容量的开关器件集成门极换流晶闸管(IGCT)逐步开始代替现有的绝缘栅双极型晶体管(IGBT)作为变流器的核心器件。以大功率三电平IGCT变流器为研究对象,针对传统IGCT变流器开关器件损耗及重触发等问题,设计了桥臂无损吸收回路应用在三电平电路上;从IGCT的结构特点出发,分析了内部重触发和外部重触发的工作原理以及应用场合,提出内部重触发阈值需合理设置,并通过实验验证了阈值是否设置合理。最后设计了3 MW的IGCT三电平变流器,针对功率组件进行了脉冲实验,针对整机进行了互馈实验,进一步验证了设计的正确性。

With the increase of the capacity of distributed generation, high voltage and large capacity switching device IGCT is required to replace the existing IGBT as the core component of the grid connected devices.Take high power three-level IGCT converter as the research object, aiming at the problems of traditional IGCT converter switching device loss and re-triggering, the bridge arm lossless absorption circuit is designed and apply in the three-level circuit. Starting from the structural characteristics of IGCT, the principle and application of internal heavy trigger and external trigger are analyzed,it is put forward that internal trigger threshold should be set reasonably and verify by experiment. Finally, 3 MW IGCT three-level converter is designed, the pulse experiment is carried out for the power component, and the mutual feed test is carried out for the whole machine, which further verified the correctness of the design.