Harmonic Analysis of Yindong ±660kV HVDC Transmission System

Based on PSCAD/EMTDC simulation platform, this paper analyses the harmonics caused by the process of rectifier and inverter and DC bias of transformer in Yindong ±660kV HVDC transmission system. The results indicate that, characteristic harmonics of 660kV HVDC system AC bus give priority to 12k±1 time harmonics and bring serious influence to the AC system of the rectifier and converter station; the characteristic harmonics of DC lines are mainly about 12k time and the voltage ripple factor is in the specified scope; both the odd and even harmonic components are increasing significantly under DC bias than that without DC bias,which thereby makes the power transformers become the severe harmonic sources.