基于VSC—MTDC的平均值建模與控制策略

江斌開 王志新

摘 要：針對基于電壓源型變流器（voltage Source Converter， VSC）的多端直流輸電（multi-terminal HVDC transmission，MTDC）系統(tǒng)的電磁暫態(tài)仿真中，每一個VSC均包含多個電力電子器件，同時采用脈寬調(diào)制技術，勢必增加VSC-MTDC仿真系統(tǒng)的數(shù)學計算量的問題，提出了一種VSC平均值模型替代VSC詳細模型，以簡化仿真系統(tǒng)?；赩SC平均值模型的簡化方法，即：忽略變流器輸出電壓中的所有高次諧波，以受控電壓源替代變流器輸出，以虛擬受控電流源表征交/直流接口關系。最后，通過搭建三端VSC-MTDC輸電仿真系統(tǒng)，對比了所提出的平均值模型與詳細模型在各個工況下的系統(tǒng)響應，仿真結果表明，VSC平均值模型與詳細模型在不同工況下，兩者的系統(tǒng)動態(tài)響應基本一致，采用平均值模型系統(tǒng)仿真速度更快，仿真效率更高。

關鍵詞：電壓源型變流器；多端直流輸電；平均值模型；電磁暫態(tài)仿真

DOI：10.15938/j.emc.（編輯填寫）

中圖分類號：TM 721 文獻標志碼：A 文章編號：1007 -449X（2018）00-0000-00（編輯填寫）

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