新型大功率光伏并网逆变器关键技术仿真研究

大型光伏电站需要的并网逆变器单机功率越来越大,然而在低功率情况下,单机大功率光伏并网逆变器效率会迅速下降。如何解决在低功率条件下大功率逆变器的效率问题成为一项值得研究的关键技术。提出了一种基于不平衡功率单元并联技术的1 MW新型光伏并网逆变器,可有效提高大功率逆变器在低功率条件下的效率和电能质量。详细地叙述了新型逆变器的工作原理,提出了不平衡功率单元无扰切换方法。基于MATLAB仿真模型对无扰切换方法进行了仿真研究,仿真结果表明并网逆变器切换过程中的扰动问题得了到很好的解决。

A Study on Key Technology Simulation for New-type Large-power Photovoltaic Grid-connected Inverter

The single unit power of grid-connected inverter required at large-scale photovoltaic power stations keeps increasing,but in the case of low-power,the efficiency of the single-unit photovoltaic grid-connected inverter efficiency declines rapidly. How to solve the problem of the large power converter under low power conditions becomes a key technology worthy of study. A new-type 1MW photovoltaic grid-connected converter based on the paralleling technology for unbalanced power units is presented to effectively improve the efficiency and electric energy quality under low power conditions. This paper introduces details of the work principle of the new type inverter,and presents an undisturbed switching method between unbalanced power units. Based on the MATLAB simulation model,a simulation study is made of the undisturbed switching method,and the simulation results show that the disturbance in the switching process of the grid-connected inverter is solved in a good way.