基于关键因子和辨识技术的光伏并网系统短路电流建模  

Modeling of short circuit current for photovoltaic connected-grid system based on the key factors and identification technology

作　　者：张尧[1,2] 晁勤[1] 李育强[1] 王一波[1] 

机构地区：[1]新疆大学电气工程学院,新疆乌鲁木齐830046 [2]新疆工程学院,新疆乌鲁木齐830091

出　　处：《电力系统保护与控制》2016年第16期84-89,共6页Power System Protection and Control

基　　金：国家自然科学基金资助(51367017);科技部国家国际科技合作专项资助(2013DFG61520)~~

摘　　要：为了提高光伏并网点短路时光伏系统输出短路电流计算准确性,提出以电压跌落程度n和光伏并网逆变器输出有功p及电网电压正序分量u^+三个特征量为关键因子,分析推导三个关键因子与光伏并网逆变器输出电流峰值Imax的关系。采用光伏并网逆变器输出对称三相正弦交流电流为控制目标的电压功率控制策略,基于系统辨识技术,建立光伏并网逆变器输出短路电流模型并辨识其相关参数。运用求和算法,获得近似的光伏并网发电系统输出短路电流模型。基于MATLAB编程软件验证了所建模型的正确性。同时与PSCAD/EMTDC搭建的恒功率控制仿真模型对比分析论证了该模型能较准确反映光伏并网发电系统输出短路电流的大小。In order to improve the accuracy of the calculation of photovoltaic system short circuit current, this paper proposes that voltage drop degree, the output active of photovoltaic connected-grid inverter, and the positive sequence component of the grid voltage are the key factors, and the relationship between the three key factors and the peak value of the output current of PV connected-grid inverter is analyzed. The voltage power control strategy for the control objective of the output symmetrical three-phase sinusoidal AC current of photovoltaic connected-grid inverter is adopted. The output current model of the PV connected-grid inverter is established and the relevant parameters are identified based on system identification technology. Using the sum algorithm, the output short circuit current model of photovoltaic connected-grid system is obtained. The built model can be verified by MATLAB programming software. At the same time, compared with the constant power control simulation model built by PSCAD/EMTDC, the model can accurately reflect the output short circuit current of PV grid connected power generation system.

关 键 词：电网短路 光伏并网逆变器 关键因子 电压功率控制 系统辨识 短路电流模型 

分 类 号：TM615[电气工程—电力系统及自动化] TM713