大型光伏电站内网拓扑结构比较分析

Comparative Analysis of Different Topologies for Large PV Plants

为迎接光伏电站平价上网的挑战,降低光伏发电的度电成本,提高光伏发电的经济性,光伏电站需要从提高能效和降低成本两方面着手。其中光伏电站不同的拓扑结构会影响电站能效和电站造价水平。参考实际运行的光伏电站案例以及设备的研究进展,从技术性能和经济性2方面对4种不同拓扑结构进行定量的比较分析。此外,文中着重研究了DC-DC变换器成本变化对系统度电成本(levelized cost of energy,LCOE)的影响。研究结果表明,系统效率高的拓扑结构,并不一定是最经济的解决方案。各种拓扑结构选择要根据具体应用场景综合分析。研究结果对大型光伏电站设计有一定的参考意义。

To meet grid parity challenges of photovoltaic（PV） plants and reduce levelized energy cost of PV generation, one solution is to improve energy efficiency, another is to reduce PV system cost. Different PV plant topologies will impact energy efficiency and PV plant cost. With reference to actual PV project cases and according to key equipment research progress, comparisons for four topologies of large PV plants are performed in view of technology and economy. Impact of DC-DC converter cost on levelized cost of energy（LCOE） is analyzed. Results show that the solutions with higher performance ratio are not necessarily the most cost-effective. Selection of PV plant topology should be according to application scenarios. This study is helpful for PV plant design.