星接三相二极管H桥级联变换器分析与设计

Analysis and Design of “Y” Connection of Three-phase Diode H-bridge Cascaded Converter

针对实际工业应用中,70%场合中高压变频器只需实现能量单方向传输的特点,分析讨论了一种可用于构成新一代高频隔离中高压变频器整流级的三相星形接法二极管H桥级联变换器。针对单相二极管H桥级联变换器本质上不能实现单位功率因数运行的问题,在分析了星形接法的三相二极管H桥型变换器的工作原理基础上,给出了三相系统可实现单位功率因数运行的理论依据,并重点讨论了三相二极管H桥型变换器运作的两种工作模式。同时采用相量图法给出了系统的最大升压比和系统电感、电容等主要参数的约束条件。最后通过仿真和实验验证了所提理论的正确性和有效性。

Considering that a medium/high voltage power converter is only supposed to realize single-directional power flowin about 70% industrial applications, a “ Y”connection of three-phase diodeH-bridge cascaded converter is analyzed, which can be used to constitute the rectifier stage in a new generation of high-frequency medium/high voltage power converter. Considering that the single-phase diode H-bridge cascaded converter cannot realize unit power factor operation, and based on the analysis of the working principle of the“ Y” connection of three-phase diodeH-bridge converter, the theoretical foundation for the unit power factor operation of the three-phase system is given, focusing on the discussion of two working modes of the converter. Meanwhile, the maximum booster ratio and the constraint conditions of the system5 s main parameters（e.g.,inductor and capacitor） are obtained using a vector diagram method. Finally, the vali-dity and the feasibility of the proposed method was validated by simulation and experimental results.