考虑直流电压无差调节的MMC-MTDC协调下垂控制策略  

Coordinated droop control strategy considering indifference regulation of DC voltage for MMC-MTDC system

作　　者：朱弘祺 李勇[1] 王姿雅[1] 李畅 曹一家[1] ZHU Hongqi;LI Yong;WANG Ziya;LI Chang;CAO Yijia(College of Electrical and Information Engineering, Hunan University, Changsha 410082, China)

机构地区：[1]湖南大学电气与信息工程学院,湖南长沙410082

出　　处：《电力自动化设备》2018年第7期196-199,213,共5页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51520105011);湖湘青年英才项目(2015RS4022)~~

摘　　要：直流电压稳定对多端直流输电(MTDC)系统的安全可靠稳定运行至关重要,对此提出一种新型协调下垂控制策略。通过建立MTDC系统的等效网络模型,推导小信号解析式,然后将小信号补偿量注入传统下垂控制中,实现MTDC系统在不同工况下直流电压的无差调节。采用PSCAD/EMTDC建立了基于模块化多电平换流器的四端直流输电系统的仿真模型,仿真结果验证了所提控制方法的有效性。在所提控制方法作用下,直流电压在扰动下会恢复到原来的稳态运行状态,避免了传统下垂控制产生的直流电压偏差,实现了直流电压的额定值运行。The stable DC voltage is crucial for the safe and reliable operation of MTDC（Multi-Terminal Direct Current）transmission system.A novel coordinated droop control strategy is proposed.The equivalent network model of MTDC system is built,and a small-signal based analytical expression is derived.The small-signal compensation term is injected into the conventional droop control to realize the indifference regulation of DC voltage in various operation conditions.The simulation model of four-terminal DC system based on modular multilevel converter is established by PSCAD/EMTDC.The simulative results validate the effectiveness of the proposed method.DC voltage will return back to the initial steady operation point under the disturbance with the proposed control method,which avoids the static error of DC voltage caused by the conventional droop control method,and implements the DC voltage operation under the rated value.

关 键 词：多端直流输电系统 下垂控制 小信号 无差调节 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM46