摘要
采用LCL滤波方式的并网逆变器具有高频衰减特性,滤波效果优于单电感滤波方式。但是LCL滤波器为无阻尼三阶系统,易发生谐振。传统的解决方法是在电容支路串入电阻增加系统阻尼,虽然可以减小谐振,但却增加了额外损耗。文中采用并网电流和电容电流双闭环的方法增加系统阻尼,对电流双闭环方案进行系统建模和稳定性分析,并用MATLAB软件进行仿真验证。结果表明该方案可抑制系统振荡,提高系统稳定性。
When adopting a LCL filter,grid-connected inverter has the characteristics of high frequency attenuation,and the filtering effect is better than L inductor.However,LCL filter is a third order system without damping,and easy to resonate.The traditional solution is adding a resistance into the capacitor branch to increase the damping of system.It can reduce resonance but actually it increased the extra loss.Double-loop control strategy with grid current feedback and capacitor current feedback is proposed in this paper,for increasing the damping of system.System modeling and stability analysis are presented,and the system is carried on the simulation with the MATLAB software.The results show that the scheme can eliminate the resonance and improve the system stability.
出处
《通信电源技术》
2012年第2期5-7,共3页
Telecom Power Technology
关键词
并网逆变器
LCL滤波器
电流双闭环控制
谐振
grid-connected inverter
LCL filter
double-loop current controller
resonance
