Appropriate HVDC transmission simulation models for various power system stability studies

HVDC stability modelling requirements differ for various studies, as well as for various systems. In particular, representation of fast dynamics may significantly slow down the time simulations due to smaller step size requirements. While such details are required in some cases, their proper simplification may be quite desirable in many routine planning and operating studies, especially for longer-term or online simulations. In this paper, detailed and response models are developed using both time domain and eigenvalue analyses, as well as comparison with field information. A novel two-time scale reduction of the detailed model is presented, which offers a flexible compromise between detail and efficiency. Appropriate model selection is discussed