基于LCL滤波器的逆变器入网电流控制技术研究

Research on Inverter Grid Current Control Technology Based on LCL Filter

逆变器作为新能源发电技术的重要接口装置,其入网电流的有效控制越来越重要。传统的控制方法会出现谐振现象,降低谐波污染的处理效果。基于此,提出了基于LCL滤波器的逆变器入网电流控制技术研究。首先,设计基于LCL的逆变器参数,获取电流谐波幅值的变化情况;设置电容串联电阻阻尼,控制谐振尖峰的阻尼;采用双极性正弦脉宽调制方式,设计入网电流反馈控制方案,保持入网电流与电网电压的同频性;设定入网电流的谐波频率,设计PR谐波补偿的幅值裕度。实验证明,此种逆变器入网电流控制技术的效果具有明显优势,基于LCL滤波器处理后的谐波含量较低,谐波污染处理的能力较强。

As an important interface device of new energy power generation technology,the effective control of its grid-connected current is becoming more and more important.The traditional control method will appear resonance phenomenon,reducing the treatment effect of harmonic pollution.Based on this,the research on the grid current control technology of inverter based on LCL filter is proposed.First,the inverter parameters based on LCL are designed to obtain the variation of the current harmonic amplitude;the capacitor series resistance damping is set to control the damping of the resonance peak;the bipolar sinusoidal pulse width modulation method is used to design the grid current feedback control scheme,Maintain the same frequency of the grid current and grid voltage;set the harmonic frequency of grid current,and design the amplitude margin of PR harmonic compensation.Experiments show that the effect of this inverter grid current control technology has obvious advantages.The harmonic content after processing based on the LCL filter is low,and the ability to deal with harmonic pollution is strong.