非理想电网下LCL逆变器并网电流质量改善研究  

Research on the Improvement of Grid-connected Current Quality for LCL Inverters Under Non-ideal Grid

作　　者：都成刚[1] 黄静[1] DU Cheng-gang;HUANG Jing(Nanjing NARI-RELA YS Electric Co.,Ltd.,Nanjing 210000,China)

机构地区：[1]南京南瑞继保电气有限公司,江苏南京210000

出　　处：《电力电子技术》2018年第11期99-103,共5页Power Electronics

基　　金：国家自然科学基金(61174037;51277156)~~

摘　　要：提出一种复合控制策略改善并网电流质量。首先搭建基于电容电流有源阻尼的LCL逆变器并网控制数学模型,通过推演控制模型的开环传递函数,揭示出电网电压谐波和电网阻抗等非理想电网因素影响并网电流质量的机理和耦合特性,提出一种基于增大基波、提高电网背景谐波频率处环路增益策略的方法,即采用比例积分(PI)加重复控制构造一种新的混合型电流调节器,实现逆变器输出电流无静差地跟踪并网正弦信号给定值,同时对负载周期性的扰动进行消除,从而有效抑制弱电网阻抗及电压背景谐波对并网电流质量的影响,降低并网电流总谐波畸变率(THD),提高并网电流质量。通过实验证明了所提控制策略的正确性和有效性。A compound control strategy is proposed to improve the quality of the grid-connected current.Firstly,the grid connected inverter of LCL capacitor current active damping control is build based on the mathematical model, the inference control model of the open-loop transfer function reveals the influence mechanism and the coupling char- acteristics of power quality harmonic voltage and the grid impedance of non ideal power factors, based on the fundamental methods to improve the power grid increases, the background harmonic frequency loop gain the implementation of strategy, the output current of the inverter is given without tracking the grid-connected sinusoidal signal static difference value.At the same time to eliminate periodic disturbance load,so as to effectively suppress the background harmonic voltage and weak network impedance effect on grid current quality, reduce the grid current total harmonic distortion（THD） ,improve the quality of grid current.The correctness and effectiveness of the proposed control strategy are proved by the experiments.

关 键 词：逆变器 并网电流 质量 

分 类 号：TM464[电气工程—电器]