MMC阀保护晶闸管的电流分配与结温计算

摘要

针对模块化多电平换流器(MMC)在直流侧发生双极短路的故障情况,建立了MMC阀闭锁后的故障电流回路,给出了MMC阀中保护晶闸管的电流分配和结温理论计算方法.在Matlab/Simulink下进行了MMC阀闭锁后故障电流回路的建模与仿真,并在MMC背靠背实验系统中进行试验研究.仿真和试验结果表明,所提分析和计算方法准确可行,对MMC实际工程中保护晶闸管的选型、损耗计算及热设计具有重要的理论指导意义.%Aiming at the fault of pole-to-pole situation in the DC side of modular multilevel converter (MMC),the fault current circuit of the MMC valve is established and the current distribution and junction temperature calculation of the protection thyristor in the MMC valve are given.The model and simulation of the fault current loop of the MMC valve is carried out under Matlab/Simulink,and the experiment is carried out in the MMC back-to-back test system.Simulation and experimental results show that the proposed method is accurate and effective.It has important theoretical significance for the selection,loss calculation and thermal design of protection thyristor in MMC.