摘要
LCL滤波器因其成本低、高次谐波衰减能力强,适用于大功率的三相并网逆变器,在各类新能源发电场合中应用广泛。LCL滤波器存在谐振问题,导致系统稳定性降低。通过建立LCL滤波器的传递函数分析LCL滤波器对系统的影响,并提出了通过电容电流前馈模拟虚拟阻抗的方法增加系统的阻尼,抑制LCL滤波器的谐振峰值,提高系统的稳定性。最后通过在Matlab/simulink中搭建仿真模型,验证算法的可行性。仿真结果表明:通过增加电容电流前馈环节的有源阻尼法可增加系统的稳定性,且不额外增加系统的损耗,三相并网逆变器的输出并网电流谐波含量低。
LCL filter has the advantages of low cost,high harmonic attenuation ability,so it is suitable for high-power three-phase grid-connected inverter.Nowadays,LCL filter is widely used in all kinds of new energy power generation.LCL filter has resonance problem,which leads to system stability reduction of three-phase grid-connected inverter.In this paper,the influence of LCL filter on the system is analyzed by establishing the transfer function of LCL filter.And by applying the capacitor current feedback,the virtual impedance of system is increased.Hence,by this active damping control strategy can increase the damping of the system,which can suppress the resonance peak of LCL filter,and improve the stability of the system.Finally,a simulation model is built in Matlab/simulink to verify the feasibility of the algorithm.The simulation results show that the active damping method can increase the stability of the system without increasing the loss of the system,and the output harmonic content of the grid-connected current of the three-phase grid-connected inverter is low.
作者
田超
TIAN Chao(State Grid Qinghai Guoluo Power Supply Company,Guoluo 814099,China)
出处
《电气开关》
2024年第3期27-30,共4页
Electric Switchgear
关键词
三相并网逆变器
有源阻尼控制
LCL滤波器
three phase grid-connected inverter
active damping control strategy
LCL filter
