轻型直流输电的不平衡故障控制策略研究  

Control Strategy Analysis on VSC- HVDC under Unbalanced Grid Conditions

作　　者：王林川[1] 李学良[1] 尚莹 李明[1] 万晶[1] 

机构地区：[1]东北电力大学电气工程学院,吉林吉林132012 [2]朝阳供电公司,辽宁朝阳122000

出　　处：《电测与仪表》2014年第9期67-72,共6页Electrical Measurement & Instrumentation

摘　　要：电网电压不平衡是VSC-HVDC系统实际运行时无法避免的问题,由于常规控制下的电压源换流器在电网电压不平衡时会将直流侧二倍频波动通过传输电路传播到相邻换流站,引起传输功率发生波动,进而影响直流输电系统的稳定运行,针对这一问题,本文对VSC行功率分析并研究其不平衡控制方案。同时采用了VSC侧与交流侧复合功率控制方法,设计了αβ静止坐标下自适应变结构滑模内环控制器。最后,在电磁暂态仿真软件PSCAD/EMTDC环境下搭建VSC-HVDC模型,仿真结果验证了该方案的有效性。Grid voltage imbalance is an inevitable problem for voltage source converter based high voltage direct current transmission（ VSC- HVDC） system. Due to the voltage source converter in conventional control would spread the second order fluctuation in DC voltage from one station to the other via the DC cables and further affect the system operation stability when the AC voltage unbalance appears,This paper takes both the VSC power and system side power into account,and adopts the adaptive variable structure sliding-mode controller whose model is derived in αβ reference frame based on the study of unbalanced control strategy of VSC. Finally,the detailed model of VSC- HVDC is set up in the environment of PSCAD / EMTDC,and the effectiveness of the proposed control strategy is verified by simulation results.

关 键 词：电网电压不平衡 高压直流输电 电压源型换流器 自适应变结构滑模控制 

分 类 号：TM271.1[一般工业技术—材料科学与工程]