基于虚拟电阻的并网逆变器谐振抑制措施的研究  

Research on method of resonance suppression for grid-connected inverter based on virtual resistor

作　　者：慕昆[1] 何国锋[2] 

机构地区：[1]河南工程学院计算机学院,河南郑州451191 [2]河南城建学院电气与信息工程学院,河南平顶山467036

出　　处：《可再生能源》2016年第6期815-820,共6页Renewable Energy Resources

基　　金：国家自然科学基金项目(61503122);河南城建学院基金资助项目(2015JBS009)

摘　　要：由于电网阻抗的耦合作用,基于LCL滤波器并网的光伏逆变器会产生谐振。为了抑制逆变器并网时产生的谐振,文章首先分析了滤波电容串联电阻的无源阻尼的控制,并在此基础上推导出等效的有源阻尼的控制方法,同时对比了无源阻尼和有源阻尼的特点,分析了阻尼系数、虚拟电阻和电容电流反馈系数之间的关系。建立了包含有源阻尼的逆变器并网闭环数学模型,在此模型基础上,分析了阻尼系数对控制系统性能的影响。最后在10 k W并网逆变器上进行了实验,实验结果表明,文章采用的有源阻尼控制策略能够有效地抑制并网谐振。For the influence of grid impedance, the resonance will occur in the PV inverters which are connected to grid with LCL filters. To suppress the resonance of grid inverter, the damping method is usually adopted, including passive damping method and active damping one. Firstly,the passive damping control method is analyzed, in which the passive resistor is connected to the capacitor of LCL filter in series. The equivalent active damping method is derived from the above-mentioned passive damping circuit by the feedback of capacitor current of LCL filter. Meanwhile, the difference between active and passive damping is compared, and the corresponding relationships among damping coefficient, virtual resistor and feedback gain of filter capacitor are conducted successively. Then the closed-loop control mathematical model of the resonant circuit is established. and the influence of virtual resistor on control system is studied. Finally, the presented control method is verified by experiments on 10 k W grid inverter. The experimental results show that the presented control strategy can effectively suppress the resonance between the grid inverter and the main grid.

关 键 词：无源阻尼 有源阻尼 并网谐振 电容电流反馈 谐振机理 

分 类 号：TM46[电气工程—电器]