Control strategy of LCL-type three-phase photovoltaic grid connected inverter  

LCL型三相光伏并网逆变器控制策略研究（英文）

作　　者：WANG Si-hua WANG Jin-qiang 王思华;王金强(兰州交通大学自动化与电气工程学院,甘肃兰州730070;甘肃省轨道交通电气自动化工程实验室,甘肃兰州730070;国家电网甘肃省电力公司白银供电公司,甘肃白银730900)

机构地区：[1]School of Automation and Electrical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China [2]Rail Transit Electrical Automation Engineering Laboratory of Gansu Province, Lanzhou 730070, China [3]Baiyin Electric Power Supply Company, State Grid Gansu Electric Power Company, Baiyin 730900, China

出　　处：《Journal of Measurement Science and Instrumentation》2019年第3期254-265,共12页测试科学与仪器（英文版）

基　　金：National Natural Science Foundation of China(No.51767014);China Railway Corporation of Science and Technology Research and Development Projects(No.2016J010-C)

摘　　要：The grid-connected inverter with LCL filter has the ability of easily attenuating high-frequency current harmonics. However, its suppression effect on the background harmonics in grid voltage is limited. A control strategy is presented, which is composed of an inner loop of capacitor current feedforward, an outer loop of grid-current feedforward and feedforward of grid voltage. The limitations and steps of parameters design for LCL filter are analyzed. Meanwhile, the capacitor current loop is employed to damp the resonant peak caused by the LCL filter and enhance the stability. The properties of different controllers are analyzed and compared, thereinto quasi-proportional-rasonant (PR) controller realizes the control with zero steady-state error of AC variables in static coordinates. In order to suppress the current distortion effected by the background harmonics in grid voltage, the feed-forward function is calculated for the grid-connected inverter with an LCL filter. After simplifying the block diagram, a full-feedforward control strategy for grid voltage is proposed. Theoretical analysis and Matlab/Simulink simulation results show that the proposed method has the advantages of high steady accuracy, fast dynamic response and strong robustness.

关 键 词：three-phase grid-connected inverter LCL filter active damping quasi-proportional-resonant (PR) control full-feedforward of grid voltages 

分 类 号：TM464[电气工程—电器]