摘要
模块化多电平变换器(modular multilevel converter,MMC)内部环流增加系统功率损耗,加剧桥臂电流畸变。针对传统PI环流控制器存在鲁棒性较差、控制精度有限等问题,将分数阶PI^(λ)控制器应用于MMC环流抑制。首先,对MMC工作特性进行分析,阐述环流产生机理。其次,研究分数阶PI^(λ)控制结构,并设计MMC分数阶PI^(λ)环流抑制策略。然后,采用经典频域法优化分数阶PI^(λ)控制器参数,并对分别采用传统PI和分数阶PI^(λ)控制器的系统环流控制性能进行对比分析。最后,在相同条件下,通过对采用上述两种环流抑制策略的MMC系统,分别在电源扰动、直流侧电压阶跃和三相不平衡工况下进行仿真研究。结果表明,分数阶PI^(λ)环流抑制器的抗电源扰动性和环流抑制能力均优于传统PI环流抑制器,更适用于MMC此类的非线性系统的控制。
The system power loss and bridge arm current distortion of a modular multilevel converter(MMC)are increased by the circulating current.In view of the poor robustness and limited control accuracy of the traditional PI circulating current controller,the fractional order PI^(λ) controller is applied to MMC circulating current suppressing.First,the working characteristics of MMC are analyzed,and the mechanism of circulating current generation is described.Second,the fractional order PI^(λ) control structure is studied and the fractional order PI^(λ) circulating current suppressing strategy is designed.Then,the classical frequency domain method is used to optimize the fractional order PI^(λ) controller parameters,and the circulating current control performance of the system using traditional PI controller and fractional order PIλcontroller is analyzed.Finally,under the same conditions,the system with fractional order PI^(λ) circulating current suppressing strategy and traditional PI circulating current suppressing strategy are simulated under AC power disturbance,DC-side voltage step and three-phase unbalance conditions respectively.The results show that the designed fractional order PI^(λ) circulating current controller outperforms the traditional PI circulating current controller in anti-power disturbance and circulating current suppressing,and is more suitable for nonlinear systems such as MMC.
作者
郑征
李佩柯
李绍令
王肖帅
靳婷婷
ZHENG Zheng;LI Peike;LI Shaoling;WANG Xiaoshuai;JIN Tingting(School of Electrical Engineering and Automation,Henan Polytechnic University,Jiaozuo 454000,China)
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2023年第1期113-121,共9页
Power System Protection and Control
基金
国家自然科学基金项目资助(61703144)
河南省科技攻关项目资助(222102240027)
河南省高等学校重点科研项目资助(20A470005)。
关键词
模块化多电平变换器
环流抑制
分数阶FO-PIλ
modular multilevel converter
circulating current suppressing
fractional order FO-PI^(λ)
