The study on advanced Three-pulse harmonic model of twelve-pulse converter

In order to design DC filters reasonably and effectively, an accurate harmonic model of converter need to be established. Since 3-pulse harmonic model can only be applied in symmetrical system without considering the effect of background harmonics, the model is not accurate enough to be used in HVDC transmission project. For above reasons, this paper proposes an advanced 3-pulse harmonic model which can apply in the asymmetric system. The advanced model has the same topology as 3-pulse harmonic model, but the influence on asymmetric factors and background harmonics of 3-pulse harmonic voltage source and 3-pulse inductance are taken into account. Finally, taking Three Gorges-Changzhou HVDC transmission project as an example, through the compare of simulation in PSCAD/EMTDC demonstrate the correctness of the advanced 3-pulse harmonic model.