[7] KANTAR E,USLUER S N,HAVA A M.Design and performance analysis of a grid connected PWM-VSI system[C].Proc.8th Int. Conf on Elect.Electron.Eng.,2013:157-161. [8] BLASKO V,KAURA V.A novel control to actively damp resonance in input LC filter of a three-phase voltage source con...
并网逆变器LCL滤波器电容电压前馈数字延时LCL filter for smoothing grid current of PV inverter is better than simple L-filter. However,there is possible instability of the LCL filter system caused by the zero impedance at the resonance frequency. The stability degradation phenomenon of the inverter ...
Wuhan 430074, Hubei Province, China)ABSTRACT: Capacitor-current-feedback active damping is an effective method to suppress the LCL-filter resonance in the grid-connected inverters. However, due to the variation of grid impedance, the LCL-filter resonance frequency will vary in a wide range, which...
图6 电网阻抗变化对谐振频率的影响Fig. 6 Influence of impedance on resonance frequency 需要指出的是,对于比例前馈控制方案其相角裕度随电网阻抗增大而急剧下降,但其低频段增益基本不受电网阻抗的影响;无前馈控制方案其低频段增益随着电网阻抗的增大而大幅减小,而其相角裕度受电网阻抗影响较小。 3 谐振前馈控制的基本...
The control challenges of LCL-type grid-connected inverter arise from the resonance problem. At the resonance frequency, the LCL filter resonance causes a sharp phase step down of −180° with a high resonance peak. This resonance peak would easily lea
Keywords:activepowerfilter;LCLfilter;resonancefrequency 引言 有源电力滤波器(activepowerfilter,APF)作 为滤除电力谐波的新技术,已成为治理谐波污染 的理想选择⋯。APF的主电路通常为三相电压 型逆变器,主电路的PWM调制导致电网电流含 有高次谐波,这会对电网的其它EMI敏感设备产 ...
7. Apparently, the resonance peak of the closed-loop transfer function can be effectively suppressed after adding the capacitor current feedback loop. However, as r3 increases, the resonance frequency has shifted and the peak first decreases and then increases. The reason is that due to the ...
Key words :micro grid;virtual synchronous generators(VSG);LCL filter;reactive damping 0 引言 分布式发电系统主要以采用两种模式或者两种模式间的相互切换运行;在分布式发电系统能量充足的情况下向电网传送能量的并网运行模式及其在电网断电、能量紧缺的情况下向重要负荷供电的孤岛运行模式[1]。如果两运行模式之间的切换...
In order to achieve optimal effect under the precondition of saving inductance magnetic core of LCL filter, a reasonable design method is brought out based on above analysis. Furthermore the method can guarantee that the resonance frequency of LCL filter is not too small to impact current ...
The method comprises the following steps of: (1) determining the total inductance value LT of the LCL filter; (2) determining the filtering capacitance value Cf of the LCL filter; and (3) determining the resonance frequency fres of the LCL filter. According to the method, the LCL filter ...