基于最小二乘法的光伏逆变器模型辨识

Photovoltaic inverter model identification based on least squares method

光伏并网逆变器是实现太阳能发电系统与电网并网的核心装置,准确的光伏逆变器模型对光伏接入电网的运行分析、故障保护等均具有重要的意义。针对目前逆变器模型研究较少,分析现有逆变器建模方法不足。结合7.68kW光伏实验发电系统搭建了光伏逆变器的测试平台,采集了逆变器输入输出数据,建立了基于最小二乘系统辨识算法的逆变器模型和模型参数估计方法,形成了一种基于实验测试的光伏逆变器建模方法。实验验证了此测试和建模方法的有效性。

Photovoltaic （PV） inverter is the core device of the gird-connected PV system. Accurate model of inverter has great significance on operation analysis and fault protection when the PV system connects to the grids. Current research on inverter model is scarce. In this paper, the deficiencies of the existing modeling methods of inverter are analyzed. For the above-mentioned reason, a laboratory PV inverter test platform has been established based on the 7.68 kW PV system. Input-output data on operating condition have been measured on this platform. The model of the inverter and model parameter estimation method based on Least Squares （LS） system identification approach are proposed. A PV inverter modeling method based on laboratory test is presented. The testing and modeling approach have been validated in the experiments.