两级三电平与两级两电平光伏变流器效率分析与比较

Efficiency Analysis and Comparison between the Three-level and Two-level PV Converter

对应用于光伏发电领域的两级两电平和两级三电平变流器的效率进行了分析计算并给出了相应的比较结果。首先分析了两种电路拓扑结构的工作过程以及损耗来源。在相同的设计要求下,分别对两电平以及三电平两种电路拓扑结构进行参数设计、器件选型。并在所选器件和所设计参数的基础上,计算出有损器件的损耗。同时,为了使损耗比较更有说服力,对于两电平和三电平两种拓扑结构,尽最大可能选择恰巧满足设计要求且为同一工艺甚至同一系列的功率器件。通过详尽的损耗计算和比较,结果说明,在相同工况下,三电平变流器的损耗要低于两电平变流器,并且随着开关频率的增高,效率优势越明显。

Two-level and three-level converter efficiency used in the field of photovoltaic power generation were analyzed and the corresponding calculated results of comparison were proposed. The two circuit topology and the loss of the source of the work process were examined firstly. Under the same design requirements, the two-level and three-level circuit topology parameter design, component selection were given. Meanwhile, in order to make the loss convincing, for two level and three level topologies, the design requirements and for the same process even in the same family of power devices were realized to the maximum extent possible. The detailed loss calculations and comparison show that, in the same condition, three-level converter＇s loss is lower than the loss of two-level converter, and with the switching frequency increases, the efficiency is more obvious.