中文摘要：

RTDS（real time digital simulation）上小步长仿真模块对开关元件的数量有严格的限制,而模块化多电平换流器（modular multilevel converter,MMC）的每个子模块都有2个电力电子开关元件IGBT。随着系统容量的不断增加,如何在有限的硬件资源中实现多电平系统的仿真成为实时仿真系统的瓶颈。对如何在RTDS大步长的环境中建立正确的IGBT元件等效模型进行了分析,根据IGBT在MMC子模块（sub-module,SM）中的工作原理,采用开关函数建立IGBT的等效数学模型。该模型能够有效减小仿真占用的资源,扩大仿真容量,在大步长环境下能够正确表征IGBT的运行特性。采用Matlab验证了所建立的IGBT模型的可行性和正确性。

英文摘要：

The quantity of switch elements in the RTDS small-step simulation model is strictly restricted, and there are 2power electronic switch element IGBT in each submodule of the Modular Multilevel Converter （MMC）. With the increasement of the system capacity, how to achieve the simulation of multilevel system with limited hardware sources becomes the bottleneck of the real-time simulation system. The valid establishment of IGBT equivalent model within the RTDS big-step environment has been analyzed in this paper. According to the working principle of IGBT in the submodule of MMC, the equivalent mathematic model with the switch function is adopted, which can effectively reduce the occupancy of resources and increase the simulation capacity, and the performance characteristics of IGBT can be correctly represented in the big-step environment. The applicability and correctness of the established IGBT model is proved with Matlab.