Simulation modeling and experiment of MMC-MTDC system based on Xsim

For a long time, the real-time simulation technology of MMC-MTDC system has been a hot spot for scholars at home and abroad. There are a huge number of power electronic components inside the MMC, resulting in a very slow simulation speed of the MMC detailed model. In addition, if the AC/DC grid of the multi-terminal flexible DC transmission system is large, it will also seriously affect the simulation efficiency. In response to this problem, an MMC speed-up model based on a controlled source is proposed, which simplifies the detailed MMC model and improves the simulation efficiency. In addition, based on the Xsim real-time simulation system, using model segmentation and parallel computing technology to decouple the four-terminal MMCMTDC system, the real-time simulation of the MMC-MTDC system is seriously completed. Comparing the simulation results, we can see that the MMC speed-up model and model segmentation strategy proposed in this paper can improve the simulation efficiency while ensuring the accuracy of the model.