摘要
针对常规基于二阶广义积分发生器的锁频环(second-order generalized integrator based frequency locked-loop,SOGI-FLL)在单相并网逆变器电压控制中对直流及谐波分量抑制能力不足,从而引起输出电压频率、相位振荡的问题,提出一种基于改进型SOGI-FLL的单相并网逆变器电压控制方法。该方法在常规SOGI-FLL控制的基础上,在电压信号输入端加入级联型谐振滤波环节来消除谐波分量;同时引入直流控制环节,借助输入电压误差估计值来消除直流分量,达到电网电压频率和相位快速跟踪效果,从而实现电压的自适应控制。使用MATLAB及RT-LAB硬件在环半实物平台,在频率突变、含直流分量及谐波分量的非理想电网环境中,对二阶广义积分器锁相环、双二阶广义积分器锁频环与改进型SOGI-FLL 3种控制方法进行仿真及实验。结果表明,所提改进型SOGI-FLL控制方法在消除直流及谐波干扰的同时,能在0.025 s内实现频率锁定,且频率偏差小于2%,可增强系统对非理想电网信号的适应能力,实现并网电压的快速跟踪,具有良好动态性能。
In order to solve the problem that the traditional second-order generalized integrator based frequency locked-loop(SOGI-FLL)has insufficient ability to suppress DC and harmonic components in the voltage control of single-phase grid-connected inverter,which causes the output voltage frequency and phase oscillation,a voltage control method of single-phase grid-connected inverter based on improved SOGI-FLL was proposed.On the basis of the traditional SOGI-FLL control,a cascaded resonant filter link is added to the input of the voltage signal to eliminate the harmonic components,and a DC control link is introduced to eliminate the DC components with the help of input voltage error estimation to achieve the fast tracking effect of grid voltage frequency and phase,so as to realize the adaptive control of voltage.Using the Matlab and RT-LAB hardware-in-the-loop semi-physical platform,a series of simulations and experiments were conducted on three control strategies:the second-order generalized integrator phase-locked loop,the double second-order generalized integrator frequency-locked loop,and the enhanced SOGI-FLL.These tests were performed in a non-ideal grid environment characterized by frequency fluctuations,DC offsets,and harmonic distortions.The findings clearly demonstrate that the proposed improved SOGI-FLL method effectively mitigates DC and harmonic disturbances while achieving frequency locking within 0.025 seconds,maintaining a frequency deviation below 2%.This approach significantly improves system adaptability to non-ideal grid conditions,enables rapid tracking of grid-connected voltage,and exhibits outstanding dynamic performance.
作者
李圣清
蒋兴龙
周志飞
曹鹏
纪岸兵
LI Shengqing;JIANG Xinglong;ZHOU Zhifei;CAO Peng;JI Anbing(School of Electrical and Information Engineering,Hunan University of Technology,Zhuzhou,Hunan 412007,China;Hunan Photovoltaic Smart Grid Control Engineering Research Center,Zhuzhou,Hunan 412007,China)
出处
《广东电力》
北大核心
2024年第10期94-102,共9页
Guangdong Electric Power
基金
国家自然科学基金项目(51977072)。
关键词
二阶广义积分器
锁频环
频率自适应
电压控制
直流分量
second-order generalized integrator(SOGI)
frequency-locked loop(FLL)
frequency adaptive
voltage control
DC component
