电网不平衡下模块化多电平变换器无源一致性控制方法  

Passivity-Consensus Based Control Method for Modular Multilevel Converter in Unbalanced Power Grid

作　　者：薛花 田广平 扈曾辉 王育飞 杨兴武 XUE Hua;TIAN Guangping;HU Zenghui;WANG Yufei;YANG Xingwu(College of Electrical Engineering,Shanghai University of Electric Power,Shanghai 200090,China;Feicheng Power Supply Company,State Grid Shandong Electric Power Company,Feicheng 271000,China)

机构地区：[1]上海电力大学电气工程学院,上海市200090 [2]国网山东省电力公司肥城市供电公司,山东省肥城市271000

出　　处：《电力系统自动化》2022年第3期85-95,共11页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51007053);上海市科技创新行动计划资助项目(19DZ2204700)。

摘　　要：针对采用传统矢量控制的模块化多电平变换器(MMC)在电网发生单相短路时易发生系统运行失稳的问题,从能量角度出发,提出形式简单、稳定性较好的无源一致性控制方法。以电网不平衡情形下正序电流期望轨迹快速跟踪与负序电流快速抑制为第1目标,通过建立MMC端口受控耗散哈密顿模型,求取不影响全局能量耗散的"无功力",简化无源性控制器设计,实现全局能量在期望平衡点处达到最小,闭环控制系统全局渐近稳定。以提升正、负序dq轴电流期望轨迹跟踪的同步性为第2目标,将当前相与相邻相的并网电流期望轨迹跟踪误差作为状态误差引入无源性控制律,提出无源一致性控制方法,实现正、负序dq轴电流期望轨迹跟踪的同步达成。基于MATLAB/Simulink的仿真结果表明:所提方法在系统单相短路故障分别与直流侧电压阶跃变化、有功功率波动、MMC参数摄动同时发生时具有良好动静态性能、宽稳定域和强鲁棒性。Aiming at the problem that the modular multilevel converter(MMC)using traditional vector control is prone to system operation instability when a single-phase short circuit occurs in the power grid,this paper proposes a simple and stable passivityconsensus based control method from the perspective of system energy.The first goal is to track the desired trajectories of positive sequence currents and suppress negative sequence currents rapidly.The model of port-controlled Hamiltonian with dissipation for MMC is established,and the“reactive force”which does not affect the global energy dissipation is obtained.Thus,the design of the passivity-based controller can be simplified and the global energy is minimized at the desired equilibrium point.The global asymptotic stability of the closed-loop control system is guaranteed.The second goal is to improve the tracking synchronousness of the desired trajectories of positive and negative sequence currents in the dq coordinate system.The desired trajectory tracking errors of grid-connected currents between neighboring phases are introduced into the passivity-based control law as the state errors,and the consensus-based control method is integrated with the passivity-based method properly,to realize the synchronization of desired trajectories tracking of positive and negative sequence currents in the dq coordinate system.The simulation results based on MATLAB/Simulink show that the proposed method has good dynamic and static performance,global stability and strong robustness when the single-phase short-circuit fault of the power grid occurs simultaneously with DC-side voltage step change,active power change and MMC parameter perturbation,respectively.

关 键 词：电网不平衡 模块化多电平变换器 端口受控耗散哈密顿模型 无源性控制 一致性控制 

分 类 号：TM46[电气工程—电器]