A Generalized Short Circuit Ratio for Multi-Infeed LCC-HVDC System
For power system engineers, this provides a more rigorous metric for assessing AC system strength in multi-infeed HVDC configurations, replacing heuristic approaches.
The paper proposes a generalized short circuit ratio (gSCR) for multi-infeed LCC-HVDC systems to mathematically measure AC strength from a voltage stability perspective, overcoming limitations of the existing rule-of-thumb MISCR. Critical and boundary gSCR values of 2 and 3 are established for strength evaluation.
The relationship between the short circuit ratio (SCR) and static voltage stability is analyzed in this paper. According to eigenvalue decomposition method, a novel concept named generalized short circuit ratio (gSCR) has been proposed for multi-infeed LCC-HVDC (MIDC) systems to mathematically measure the connect-ed AC strength from the point view of voltage stability, which can overcome the rule-of-thumb basis of existing multi-infeed short circuit ratio (MISCR) concept. In gSCR, two indices, the critical gSCR (CgSCR) and the boundary gSCR (BgSCR) are developed to quantitatively evaluate if the connected AC system is strong or weak, in which CgSCR=2 and BgSCR=3 are two critical values for strength evaluation. Finally, numerical simulations are conducted to validate the effectiveness of the proposed gSCR concept.