三相单级光伏并网系统对配电网侧负荷建模的影响

Impact of Three-phase Single-stage Photovoltaic System on Distribution Network Load Modeling

基于MATLAB/Simulink建立了三相单级光伏并网系统的动态模型,研究了其外特性,指出含有三相单级光伏并网系统的广义负荷模型结构,只需在传统的综合负荷模型结构的虚拟母线上增加一个有功随电压变化的有功功率源。待辨识参数需要增加光伏阵列的3个特性参数、与光伏阵列并联的电容器的电容值、光伏发电相对纯负荷的比例以及电压控制器的比例与积分放大倍数,共增加7个参数。提出了参数辨识策略:先通过统计调查数据采用聚合算法,得到聚合后的广义负荷参数,低灵敏度参数可以固定为聚合参数,高灵敏度参数可在聚合后的参数附近采用遗传算法辨识。算例表明,采用所提出的模型与参数辨识策略辨识出来的参数的描述能力、泛化能力较好。

This paper builds a MATLAB/Simulink dynamic model of three-phase single-stage photovoltaic system connected with distribution network,and its external characteristics is studied.The research results show that the model frame of the generalized load model of distribution network which contains three-phase single-stage photovoltaic system can be obtained by adding a variable active power source to the fictitious bus of conventional synthesis load model.Seven parameters to be identified are added to that of the conventional synthesis load model,i.e.three characteristic parameters of the photovoltaic array,the capacity of the electric capacitor in parallel with photovoltaic array,the proportion of three-phase single-stage photovoltaic system relative to pure load,the proportion amplification constant and the integral amplification constant of voltage regulator.A parameters identification strategy is proposed.Firstly the loads are aggregated.Then the low-sensitive parameters are fixed as aggregation values,while high-sensitive parameters are identified near the aggregation value by genetic algorithm.The characteristic fitting capability and the generalization capability of the proposed generalized load model are validated by a simulation example.