一种直流侧带双辅助二极管的24脉波整流器

A 24-pulse Rectifier With Two Auxiliary Diodes at DC Side

为进一步提高12脉波整流器的谐波抑制能力以满足工业应用要求,该文通过对常规12脉波整流器的电路结构进行改造,得到一种直流侧带双辅助二极管的新型24脉波整流器。首先,分析新型24脉波整流器的工作原理,建立输入电流、输出电压和平衡电抗器匝比之间的函数关系,得到使输入电流总畸变率获得最小值时的平衡电抗器匝比;然后,计算最优匝比条件下整流器中主要磁性器件的容量及辅助二极管的电压电流等级;再次,讨论零序电流抑制电抗器电感值的确定方法。理论分析结果表明,直流侧双辅助二极管的交替导通和调制将输入电流的台阶数增加1倍,使整流器获得总畸变率更低的输入电流。最后,搭建一台输出功率为3kW的实验样机对所提理论分析的正确性和提出方案的有效性进行验证。

To further improve the harmonic suppression ability of 12-pulse rectifier to meet the requirements of industrial application,a new 24-pulse rectifier with two auxiliary diodes at DC side is obtained by modifying the circuit structure of conventional 12-pulse rectifier.Firstly,the working principle of the new 24-pulse rectifier was analyzed,and then the function relation between input current,output voltage and turns ratio of the inter-phase reactor was established,the turn ratio of the inter-phase reactor was obtained when the total harmonic distortion(THD)of the input current is minimized.Then the capacity of the main magnetic devices and the voltage and current level of the auxiliary diode in the rectifier under the condition of optimal turn ratio were given.Finally,the determination method of the inductance value of zero-sequence blocking transformer(ZSBT)was discussed.The theoretical analysis results show that the alternating conduction and modulation of auxiliary diodes on DC side will double the step number of input current,rectifier get lower input current THD.An experimental prototype with output power of 3kW was built to verify the correctness of the theoretical analysis and the effectiveness of the proposed scheme.