并网变流器功率单元设计与直流载流需求研究

Study on Power Unit Design and DC Busbar Current Carrying Demand for Grid-connected Converter

功率单元是变流器中的核心部件,随着变流器容量增大,功率单元需要模块化设计。本文结合业内产品总结了目前主流的模块化技术路线,比较了半桥功率单元和全桥功率单元的优缺点,并分析了功率单元设计中的关键技术。指出了模块直流母排电流非连续、不规则的特点,鉴于该电流对母排设计具有重要参考意义而目前相关研究文献匮乏的现状,本文开展理论推导,给出了直流母排载流需求的计算方法,并进行了仿真和实验验证。

Power unit is a core component of converters. With the converter capacity increases, power unit need to be designed by modular method. In this paper, currently mainstream modular technical routes are summarized, advantages and disadvantages of half bridge and full bridge power unit are compared, and key technology in the design of power unit is analyzed. It is pointed out that, the DC busbar current has the attribute of irregularity and discontinuity. This is important to DC busbar design, but the research in this direction is relatively poor. This paper derives the related theoretical formula to calculate the DC busbar current. The results of simulation and experiment verify the correctness of the formula.