摘要
研究了弱电网背景下直驱风电机组网侧变流器并网电流频率耦合效应产生机理及其抑制对策。通过建立考虑电网阻抗及直流电压外环、锁相环等不对称控制环节影响的网侧变流器等效阻抗以及能够直观反应频率耦合效应的耦合导纳模型,分析了各关键作用因子对频率耦合效应的影响,并基于等效阻抗频率特性曲线分析了弱电网条件下频率耦合效应对系统稳定性产生的影响机理。针对并网电流中出现的频率耦合振荡风险,提出了一种基于二阶广义积分器的并网电流频率耦合分量抑制策略,理论分析表明此控制策略能够有效阻抑频率耦合效应,进而提高系统稳定性。仿真与实验结果验证了所提控制策略的有效性及引入此控制策略后直驱风电机组网侧变流器系统的鲁棒性。
This paper focuses on the generation mechanism and the suppression control strategies of the frequency coupling component of the grid-connected current in the permanent magnet synchronous generator(PMSG)grid-side converter under a weak AC grid.A coupling admittance model of the frequency coupling effect for the grid-side converter is established considering the influence of grid impedance,DC voltage loop,phase-locked loop and current loop.Aiming at the frequency coupling component in grid-connected current,a SOGI-based frequency coupling correction control strategy is proposed.Theoretical analysis shows that the control strategy can effectively suppress the frequency coupling effect and improve the stability of the system.The simulation and experimental results also prove the effectiveness of the control strategy and the robustness of the grid-connected converter system after introducing the control strategy.
作者
徐海亮
聂飞
王诗楠
XU Hailiang;NIE Fei;WANG Shinan(College of New Energy,China University of Petroleum,Qingdao 266580,Shandong Province,China)
出处
《电网技术》
EI
CSCD
北大核心
2021年第5期1687-1697,共11页
Power System Technology
基金
国家自然科学基金项目(52077222,51507190)
山东省自然科学基金项目(ZR2020ME202)。
关键词
弱电网
直驱风电机组
网侧变流器
频率耦合
稳定性
weak AC grid
permanent magnet synchronous generator(PMSG)
grid-side converter
frequency coupling
stability
