多脉波整流器直流侧无源谐波抑制机理研究

为提高多脉波整流器的直流侧无源谐波抑制能力,研究了基于两抽头变换器的24脉波整流器直流侧谐波抑制机理。根据抽头变换器的结构及安匝平衡原理,分析了抽头变换器的功能及工作模式,研究了抽头变换器的工作模式对整流桥输出电流、整流器输入电流及负载电压的影响,给出了抽头变换器变比的理论最优值。理论分析及实验结果表明,抽头变换器的端电压会使其所接的两个二极管交替导通,对整流桥输出电流进行调制,进而产生环流,该环流流经交流侧时会抵消原输入电流中的12k±1(k为奇数)次谐波。另外,抽头变换器所接的两个二极管的交替导通,会在负载上产生附加电压,附加电压的存在可以显著降低负载电压的纹波系数。相应的实验结果验证了理论分析的正确性。

Harmonic reduction mechanism at DC link of multi-pulse rectifier

In order to improve the ability of harmonic reduction at DC link of multi-pulse rectifier ( MPR) ,the harmonic reduction mechanism at DC link of 24-pulse rectifier with double-tapped inter-phase reactor ( IPR) was analyzed.According to the winding configuration of double-tapped IPR and Am-pere-Turn balance,the function and operation mode of double-tapped IPR were analyzed.The effect of op-eration mode on output currents of the two bridge rectifiers,input current of rectifiers,load voltage were also analyzed,and the theoretical value of turn ratio of IPR was calculated.Theoretical analysis and exper-imental results show that the conduction in turn of the two diodes connected with IPR will produce a cir-culating current to modulate the output currents of the bridge rectifiers.When the circulating current flows through the input mains,it reduces the (12k ±1)th(k is odd number) harmonics.In addition,conduction in turn of the two diodes produces an additional voltage on the load voltage,which depresses the ripple co-efficient of load voltage.Experimental results validate the correctness of theoretical analysis.