基于VSC—MTDC的平均值建模与控制策略

江斌开 王志新

摘 要：針对基于电压源型变流器（voltage Source Converter， VSC）的多端直流输电（multi-terminal HVDC transmission，MTDC）系统的电磁暂态仿真中，每一个VSC均包含多个电力电子器件，同时采用脉宽调制技术，势必增加VSC-MTDC仿真系统的数学计算量的问题，提出了一种VSC平均值模型替代VSC详细模型，以简化仿真系统。基于VSC平均值模型的简化方法，即：忽略变流器输出电压中的所有高次谐波，以受控电压源替代变流器输出，以虚拟受控电流源表征交/直流接口关系。最后，通过搭建三端VSC-MTDC输电仿真系统，对比了所提出的平均值模型与详细模型在各个工况下的系统响应，仿真结果表明，VSC平均值模型与详细模型在不同工况下，两者的系统动态响应基本一致，采用平均值模型系统仿真速度更快，仿真效率更高。

关键词：电压源型变流器；多端直流输电；平均值模型；电磁暂态仿真

DOI：10.15938/j.emc.（编辑填写）

中图分类号：TM 721 文献标志码：A 文章编号：1007 -449X（2018）00-0000-00（编辑填写）

Abstract： Aiming at the problem that the mathematical calculation of the VSC-MTDC simulation system is greatly increased by the number of power electronic component switches and pulse width modulation technology of VSC in the electromagnetic transient simulation， an average-value model of VSC is proposed to replace the detailed model of VSC in order to simplify the simulation system. The simplified method based on the VSC average-value model， that is， the high-order harmonic of the output voltage of the converter is neglected. The output of the converter is replaced by the controlled voltage source， and the AC / DC interface relationship is expressed virtual controlled current source. At last， a 3-terminal VSC-MTDC transmission simulation system is built， and the system responses in different cases of detailed model are compared with the average-value model. The simulation results show that the system responses of the two kind of models are nearly the same， and the average-value model greatly speeds up the system simulation and improves the simulation efficiency.

Keywords： voltage source converter； Multi-terminal HVDC； average-value model； electromagnetic transient simulation