输入侧断相对多脉波整流器直流侧谐波抑制方法的影响

Effect of open-phase in input terminal on parallel-connected multi-pulse rectifier using harmonic reduction at DC side

为描述多脉波整流器断相时的故障特征,分析了断相对使用直流侧谐波抑制方法的多脉波整流器的影响。以使用两抽头变换器的24脉波整流器和使用有源平衡电抗器的12脉波整流器为例,分析了正常工作和断相运行时整流器各处的电压和电流特征。通过理论分析和实验验证,结果表明断相会导致两整流桥输出电压的瞬时差等于零,进而使抽头变换器和有源平衡电抗器不能产生环流去抑制输入电流谐波;同时,断相运行也将使负载电压纹波显著增大,即断相将导致输入侧和负载侧电能质量恶化。相关结论可为并联型多脉波整流器断相故障的分析和实时处理提供理论依据。

In order to describe the fault feature of the multi-pulse rectifier(MPR)when open phasing,the effect of the open-phasing was analyzed on the MPR when using the harmonic reduction method.To set the 24-pulse rectifier with double-tapped inter-phase reactor(IPR)and 12-pulse rectifier with active IPR as examples,the current and voltage characteristic were analyzed under normal operation and open phase,respectively.The theoretical analysis indicates that the instantaneous difference of the two bridge rectifiers′output voltages is equal to zero under open phase,and the MPR is equivalent to be two single-phase rectifiers with the equal input voltages,which cause that the double-tapped IPR and active IPR cannot generate circulating current to eliminate the harmonics in input terminals.In addition,the open phase also results in the large ripple of load voltage,which means the power quality of dc side and ac side will be worsen.The results provide the basis of analysis and real-time processing for parallel-connected MPR under open-phase.