摘要
基于模块化多电平换流器MMC(modular multilevel converter)的柔性直流输电HVDC(high voltage directcurrent)系统日益受到关注。传统dq坐标系下双闭环比例积分PI(proportional integral)控制需要前馈解耦,特别是在电网电压不平衡时,需要正负序分解,而环流抑制的方法也过于复杂。在分析模块化多电平换流器型直流输电MMC-HVDC工作原理的基础上,给出了αβ坐标系下,基于准比例谐振QPR(quasi proportional resonant)控制器的MMC-HVDC的控制策略,无需前馈解耦和正负序分解,控制器设计简单,同时也给出了一种基于QPR控制器的有效抑制2倍频环流的新方法。在PSCAD(power systems computer aided design)中对上述控制策略进行了仿真验证,仿真结果表明了所提策略的正确性和有效性。
Based on the modular multi-level converter a flexible high voltage direct current （HVDC）system is attracting more and more attention.Traditional double closed loop proportional integral （PI）control strategy in dq coordinates needs decoupling and feed-forward compensation. Especially for the unbalanced power grid voltage, it needs the positive and negative sequence decomposition with complex method of circulation current suppression. In this paper, after the intro- duction of the working principle of modular multilevel converter-high voltage direct current （MMC-HVDC）, a control strategy is proposed based on the quasi proportional resonant（PR）controller with aft coordinates. The method can avoid decoupling and feed-forward compensation with the positive and negative sequence decomposition.The controller is sim- ple to design.This paper also presents an effective method based on the quasi PR controller to suppress secondary circu- lation. The proposed strategy is verified in PSCAD and the simulation results show that the proposed strategy is correct and effective.
出处
《电力系统及其自动化学报》
CSCD
北大核心
2016年第11期70-75,共6页
Proceedings of the CSU-EPSA
基金
高等学校博士学科点专项科研基金资助项目(20126118110009)
陕西省重点学科建设专项基金项目(105-5X1301)
关键词
柔性直流输电
模块化多电平换流器
准PR控制器
环流抑制
电网电压不平衡
flexible high voltage direct current （HVDC）
modular multilevel converter （MMC）
quasi-PR controller
circulation current suppression
unbalanced power grid voltage
