Characteristics analysis and practical model of UHVDC systems under large disturbance

UHVDC projections will make uncertain impact on bulk power grid. Therefore, it is necessary to found the model which is suitable for simulation of AC grid. In this paper, the impacts of large disturbances on UHVDC systems are presented and practical models of UHVDC under large disturbances are proposed. Firstly, the characteristics of UHVDC output power under different large disturbances are clearly explained, based on the simulation in PSCAD. Furthermore, practical models of UHVDC systems under large disturbances are proposed for AC grid simulation by power curve fitting, which can capture the key dynamic characteristics. Finally, the proposed models are used in a real case, and the effectiveness of the proposed model is verified.