大型光伏电站与电网谐波交互影响

Harmonic Interaction Between Large-scale Photovoltaic Power Stations and Grid

大型光伏电站的并网将导致配电网谐波呈现出高频次、宽频域等特性,以往被忽视的输电线路分布电容对该类型谐波的影响将十分显著。首先给出光伏电站高低次谐波电流输出特性,建立光伏电站配网基波域数学模型。在此基础上,提出大型光伏电站谐波串并联谐振数学模型,分析谐波串并联谐振的机理,定量分析谐波电压放大系数及谐波电流放大系数与输电距离、谐波次数及谐波类型的关系。按照青海格尔木某50?MVA大型并网光伏电站搭建实例仿真模型,并且对该电站及配网进行数据实测,通过仿真数据及实测数据的对比验证结论的正确性。

Grid-connected photovoltaic （PV） power station of large scale may lead to high frequency and wide-band frequency of power system harmonics. The effects caused by distributed capacitance of transmission line which used to be neglected on these harmonics turns to be prominent. Output characteristics of high and low harmonics in PV station were given at first. Mathematic model in fundamental domain of PV station and grid was established. On the basis, series-parallel resonant mathematic model of harmonic was proposed and mechanism was discussed. Meanwhile, relationships among harmonic amplification factor and transmission distance, harmonic order as well as type were analyzed. The simulation model of large-scale PV station was given according to the local PV station in Qinghai province, and real data was measured. The proposed scheme was verified by contrast of simulation data and real data.