局部阴影条件下光伏阵列的串联特性分析

以光伏组件的双二极管模型为基础对串联输出特性进行了系统分析,包括分析比较有、无旁路二极管的串联特性、热斑成因,旁路二极管作用机理和不同连接方式以及等效串联结构的光照平衡的影响。结果表明,局部阴影使光伏阵列的I-U曲线呈阶梯状、P-U曲线呈现多峰;旁路二极管抑制热斑作用明显,其重叠和不重叠连接方式效果不同,重叠区的阴影可增大最大输出电流,且最大输出电流与遮阴程度正相关;多个光伏电池元共用一个旁路二极管可有效减少多峰数;等效串联结构的光照平衡可以消除阴影影响。

Modeling and Series Characteristics Analysis of the PV Array under Partial Shading Conditions

Series characteristics were analyzed systematically based on the two-diode model,including series characteristics with and without by-pass diodes,the hot spot formation reasons,the effect and mechanism of by-pass diode and the effect of different connection of it,the influence of irradiance balance of the equivalent series module.The results show that the PV array exhibits a step-like I- U characteristic and multiple peaks in the P- U characteristic and the by-pass diode has a good effect on restraining hot spots,the overlap and non-overlap by-pass diode have different effect and the shadows in the overlap can increase the maximum output current. Besides,that multiple photovoltaic cells share a by-pass diode can effectively reduce the multiple peak number. Moreover,the irradiance balance of the equivalent series module can eliminate partial shading effects.