有源中点钳位型五电平整流器电容建压方法

A Capacitor Voltage Buildup Method for Active Neutral-point-clamed Five-level Rectifier

有源中点钳位型五电平(active neutral-point-clamed five-level,ANPC-5L)变换器在中高压大功率变频传动场合应用潜力巨大。针对传统电容建压方法无法适用于ANPC五电平整流器内部电容器的建压问题进行研究,在充分分析了其拓扑结构特点的基础上,提出了一种ANPC-5L整流器的电容建压方法,在不增加其他外部充电设备的前提下,通过控制每相桥臂中不同开关管的导通与关断,对整流器中的所有电容器进行充电。在分析不同阶段建压电路结构特点的基础上,推导出各阶段电容器建压公式,并给出建压速度与等效预充电阻及电容器容量的关系。该方法具有充电速度快、效果好、通用性强等特点,同时还具有成本低、操作简单、易于控制等优点。最后,以ANPC-5L整流器为例,进行了仿真和实验验证,仿真和实验结果均验证了所提电容建压方法的正确性和有效性。

The active neutral-point-clamed （ANPC） five-level converter has been adopted widely in the field of high-voltage and high-power applications. The capacitor voltage buildup method for the ANPC five-level rectifier was studied, because the traditional voltage buildup method cannot be used in the ANPC five-level rectifier. A general capacitor voltage buildup method for ANPC five-level rectifier was proposed after the topological structure characteristics were analyzed. This method is that the capacitor voltage was buildup by controlling some IGBTs open or off only with a pre-charging transformer. The formula of capacitor voltage buildup is deduced after analyzing of the characteristics about the capacitor voltage buildup circuits in different stages. The surface of the relationship among the capacitor voltage buildup speed, the equivalent pre-charge resistance and the capacitor capacity was given. The method has many characteristics such as high charging speed, good effects, strong versatility, at the same time also has the advantages of low costs, simple operation and easy to control. At last, the results of the simulation and the experiment of the ANPC five-level rectifier were presented to verify the correctness and the validity of the method.