电测与仪表2017，Vol.54Issue(2)：18-24,45,8.
不对称电网电压下MMC-HVDC系统功率波动抑制策略研究
Study on power fluctuation suppression strategy of MMC-HVDC system under unbalanced grid voltage
摘要
Abstract
Unbalanced grid voltage will induce fluctuation twice times the grid frequency of active and reactive power at AC side of MMC in Modular Multilevel Converter based High Voltage Direct Current (MMC-HVDC) system.Aiming at this problem,this paper proposes to transform grid voltage and current into positive sequence dq coordinate system to calculate reference current which can suppress fluctuation of active power and reactive power simultaneously.Moreover,under the unbalanced grid voltage,d-axis and q-axis component of voltage will be comprised of twice times the grid frequency component which is induced by negative sequence component in the positive sequence dq coordinate system in addition to DC component.Overall control performance of system will be influenced without considering twice times grid frequency component informed above in the design of phase-locked loop(PLL).This paper designs frequency adaptive PLL based on twice times grid frequency notch filter,which can track phase and calculate amplitude of positive sequence voltage and positive sequence d-axis and q-axis component of negative sequence voltage,as well as will be used to realize dq transformation in proposed control strategy and calculate reference current in power fluctuation suppression strategy.Feasibility and effectiveness of proposed control strategy have been proven through simulation.关键词
MMC-HVDC/电压不对称/功率波动抑制/频率自适应锁相环Key words
MMC-HVDC/unbalanced grid voltage/power fluctuation suppression/frequency adaptive PLL分类
信息技术与安全科学引用本文复制引用
刘英培,潘朏朏,栗然,张栋..不对称电网电压下MMC-HVDC系统功率波动抑制策略研究[J].电测与仪表,2017,54(2):18-24,45,8.基金项目
国家自然科学基金资助项目(51607069) （51607069）
中央高校基本科研业务费专项基金资助项目(2014MS89) （2014MS89）
西华大学研究生创新基金资助项目(ycjj2015100) （ycjj2015100）
