基于Pscad/EMTDC自定义建模的MMC电磁暂态仿真技术

Technique of Electromagnetic Transient Simulation Based on the User-defined Model of Pscad/EMTDC for MMC

为了精确模拟仿真模块化多电平换流器(MMC)接入电网的暂态特性,需要开展计及MMC结构、特性及控制保护策略的电磁暂态仿真技术研究,以适应新一代电力电子技术在电力系统中应用的研究。本文通过Pscad/EMTDC自定义建模功能实现了MMC及其控制保护功能暂态建模。综合考虑MMC及其控制保护的特点,设计了MMC模型的整体结构,利用Pscad/EMTDC接口C语言实现了自定义元件,并结合模块化建模的方式,构建MMC及其控制保护功能的各个环节,基于此建立了MMC接入电网的电磁暂态仿真模型。利用该模型开展了MMC动态仿真,结果表明,模型能有效模拟MMC控制环节、子模块电容电压等暂态过程。建立的模型便于扩展且能适应不同应用场合,可用于开展基于MMC的柔性交直流输电电磁暂态特性及控制保护功能研究。

In order to simulate the transient characteristic of the MMC integrated power network accurately, it needs to study the electromagnetic transient simulation technology include the structure, control-protection strategy of MMC, to adapt the application of the new generation technology of power electronics in power system. By the user-defined model of Pscad/EMTDC, the solution for precise modeling of MMC and its control-protection is proposed. Taking into account the characteristic of MMC and its control-protection, the transient modeling with C program interfacing to Pscad/EMTDC for MMC is presented. The overall structure of modeling is designed firstly. Combined with the user-defined component and modular modeling mode, MMC and its control-protection is modeled by some functional modules, and the model of power network with MMC integrated is constructed. The dynamic simulation is conducted, and the results show that it can simulate the dynamic process of sub module voltage, control of MMC, etc., validity. The MMC model can adapt to different applications, which can be used for electromagnetic transient analysis and control-protection testing for flexible AC transmission and VSC-HVDC based on MMC.