基于混合型MMC和快速真空开关构建的柔性直流电网  

VSC-HVDC Power Grid Based on Hybrid MMC and Fast Vacuum Breaker

作　　者：蔡普成 向往[1] 周猛[1] 倪斌业 左文平[1] 文劲宇[1] 林卫星 CAI Pucheng;XIANG Wang;ZHOU Meng;NI Binye;ZUO Wenping;WEN Jinyu;LIN Weixing(State Key Laboratory of Advanced Electromagnetic Engineering and Technology,Huazhong University of Science and Technology,Wuhan 430074,China;TBEA China Xinjiang Sunoasis Co.,Ltd.,Urumchi 830011,China)

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学),武汉430074 [2]特变电工新疆新能源股份有限公司,乌鲁木齐830011

出　　处：《南方电网技术》2019年第11期42-50,共9页Southern Power System Technology

基　　金：国家自然科学基金智能电网联合基金项目(U1766211);Supported by the Smart Grid United Foundation Project of the National Natural Science Foundation of China(U1766211)

摘　　要：采用架空线的柔性直流电网在大规模风电、光伏等新能源的汇集、输送和并网中有很好的应用前景。由于直流故障电流上升速度快、峰值高,柔直工程中一般采用高速大容量直流断路器隔离直流故障。然而,直流断路器制造难度大、成本高,降低了直流电网的经济性,并且其可行性还有待实际工程验证,这在一定程度上阻碍了直流电网的大规模发展与建设。为此,本文提出了一种基于混合型MMC和快速真空开关的直流电网组网方案。该方案充分利用混合型MMC强大的控制能力,可以保证换流器在直流故障期间不闭锁,使得直流电网在直流故障被清除后可以快速、柔性地切换到新的运行状态,缩短直流电网功率中断时间,提高直流电网的利用率。同时可以在直流线路中安装快速真空开关来替代高速大容量直流断路器,以减小直流电网的建设成本,大幅度提高直流电网的经济性。最后,基于PSCAD/EMTDC平台仿真验证了本方案的正确性与合理性。There is good application prospect in the transmission and grid-connection of large-scale wind power and other renewable energy of VSC-HVDC transmission grid with overhead lines.Due to the rapid rise of DC current under DC line fault,DC circuit breaker with high speed and large capacity is generally used to isolate DC faults in the VSC-HVDC engineering.However,the manufacture of DC circuit breaker is difficult and costly,which hinders the development of DC grid.Then,VSC-HVDC transmission grid based on hybrid MMC and fast vacuum breaker is proposed.It makes full use of the control ability of hybrid MMC,it can ensure that the converter does not lock during the DC fault,so that the DC power grid can quickly and flexibly switch to a new operation state after the DC fault is cleared.The power interruption time of the DC grid is shortened,which can improve the utilization of the DC grid.At the same time,the fast vacuum breakers are installed in the DC line to replace the high-speed large-capacity DC circuit breaker,so as to reduce the construction cost of the DC grid.Finally,simulations based on PSCAD/EMTDC platform are executed to verify the correctness of this method.

关 键 词：柔性直流电网 架空线 混合型MMC 主动限流控制 

分 类 号：TM721[电气工程—电力系统及自动化]