基于电容电压前馈的LCL逆变器并网控制  

Grid-tied Control of LCL Inverter Based on Capacitive Voltage Feed-forward

作　　者：李锐[1] 邓磊[1] 李小谦[1] 徐正喜[1] 刘邦银 LI Rui;DENG Lei;LI Xiaoqian;XU Zhengxi;LIU Bangyin(Wuhan Second Ship Design and Research Institute,Wuhan 430000,Hubei,China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology,Wuhan 430000,Hubei,China)

机构地区：[1]武汉第二船舶设计研究所,湖北武汉430000 [2]强电磁工程与新技术国家重点实验室,湖北武汉430000

出　　处：《电气传动》2017年第7期37-42,共6页Electric Drive

摘　　要：并网逆变系统中,LCL滤波器相比单电感滤波器具有更优的滤波性能,然而引入了谐振点,降低了系统稳定性。揭示了存在数字延时LCL型并网逆变器逆变侧电流单环控制的稳定性恶化现象,提出了一种基于电容电压前馈的逆变侧电流控制方案,该方案通过电容电压前馈使系统降阶,从而有效地改善了系统的稳定性,同时分析了延时和前馈系数对电容电压前馈效果的影响。所提控制方案的有效性在自行研制的630 k W三相逆变器上得到了实验验证。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 with inverter side current control with increasing of digital delay was revealed.Then inverter side current control scheme based on capacitive voltage feed-forward was proposed.The inverter side current control scheme based on capacitive voltage feed-forward realized the reduction of system order by the feed-forward of capacitance voltage and effectively improved the stability of system.Then the influences of digital delay and feed-forward coefficient on the stable effect of capacitance voltage feed-forward were analyzed in detail.The effectiveness of the control strategy is verified by experimental results in a630kW three-phase grid-tied inverter.

关 键 词：并网逆变器 LCL滤波器 电容电压前馈 数字延时 

分 类 号：TM431[电气工程—电器]