Protection scheme of voltage sourced converters based HVDC system under DC fault

In this paper, the validity of EMTP model for a voltage sourced converter based HVDC system is established by comparing it with the experimental results of AC-DC simulator (analog type). By using this model, a new protection to suppress the overvoltage under DC fault is developed and its effectiveness is demonstrated by EMTP simulations. Moreover, it is shown that this protection scheme can also be applied to long DC transmission systems as well.