电网不平衡条件下模块化多电平变换器控制策略

doi:10.16180/j.cnki.issn1007-7820.2022.01.013

摘要/Abstract

摘要：

当电网处于电压不平衡状态时,MMC的内部会产生环流。环流中存在二倍频的正序、负序和零序分量,增加了系统的不稳定性。针对电网不平衡情况下MMC二倍频环流抑制的问题,文中提出一种基于线性自抗扰控制器的环流抑制策略。根据瞬时功率理论推导出环流参数的数量关系,在此基础上设计了基于线性自抗扰控制策略的环流控制器来抑制环流。最后利用MATLAB/Simulink软件对所提出的控制策略进行仿真验证。仿真结果表明,该控制策略能够有效地抑制环流,增加系统的稳定性。

关键词: 电网不平衡, MMC, 自抗扰控制器, 环流, MATLAB/Simulink, 二倍频, 环流抑制, 仿真模型

Abstract:

When the power grid is in a voltage unbalanced state, a circulating current will be generated inside the MMC. The positive sequence, negative sequence and zero sequence components of double frequency exist in the circulating current, which increases the instability of the system. In view of the problem of MMC double-frequency circulating current suppression under unbalanced power grids, this study proposes a circulating current suppression strategy based on a linear active disturbance rejection controller. According to the instantaneous power theory, the quantitative relationship of the circulating current parameters is derived. On this basis, the circulating current controller based on the linear active disturbance rejection control strategy is designed to suppress the circulating current. Finally, the proposed control strategy is simulated by MATLAB/Simulink software. The simulation results show that the control strategy can effectively restrain the circulation and increase the stability of the system.

Key words: unbalanced grid voltage, MMC, ADRc, circulation, MATLAB/Simulink, double frequency, circulation suppression, simulation model

中图分类号:

TP202

牛帅臣,王福忠,韩耀飞,何国锋,牛叶克. 电网不平衡条件下模块化多电平变换器控制策略[J]. 电子科技, 2022, 35(1): 80-86.

NIU Shuaichen,WANG Fuzhong,HAN Yaofei,HE Guofeng,NIU Yeke. Control Strategy of Modular Multilevel Converter Under Unbalanced Grid Voltage[J]. Electronic Science and Technology, 2022, 35(1): 80-86.

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参数	参数值
直流电压/V	800
直流电容/mF	1.88
桥臂电感/mH	5
桥臂电阻/Ω	15
定子电阻R/Ω	2.875
载波频率/kHz	2
K_T	16
b₀	10