Admissible HVDC infeed capacity evaluation of receiving-end power grids.

• A two-stage AHIC assessment model is proposed, in which the first-stage problem seeks the maximum admissible capacity and the optimal location of the infeed HVDC links, while the second-stage problem checks the adaptability of the produced first-stage decisions on basis of ensuring system security under normal and serious contingency cases, i.e., bi-pole blocking and communication failure of HVDC links. Leveraging this model, a reliable AHIC can be obtained. • A modified multi-infeed operation effective short-circuit ratio (MMOESCR) index based on the voltage sensitivity is formulated to take into account the function of Var reserves at different AC buses in resisting commutation failure (CF) of HVDC links. This metric is coupled into the proposed model to quantify the CF immunity of the receiving-end power grid. • A solution algorithm based on generalized Benders decomposition (GBD) is developed to solve the proposed model. This approach is applied to assess the AHIC of Henan Grid (a large-scale provincial grid in China), which can provide more efficiently future installation plan of multi-feed HVDC links in the targeted AC network. To fulfil the cross-regional bulk power delivery of renewable energy and alleviate the power shortage pressure of load centers, a number of line-commutated converter-based high voltage direct current (LCC-HVDC) transmission projects have been deployed in worldwide. Due to the system-wide operating risk sharply escalated with the intensively infeed of multiple large-capacity HVDC links, a vital knowledge gap exists in understanding the maximal admissible HVDC infeed capacity (AHIC) of receiving-end power grids. To tackle this issue, this paper proposes a novel AHIC evaluation method, which determines the maximal allowed total number and capacity of HVDC links that the receiving-end grid can accommodate while taking into account multi-preconceived fault security requirements. An improved dynamic system strength criterion is developed to assessing the immunity of post-contingency HVDC commutation failures (CF), which creatively considers the support effect from all AC buses based on the voltage sensitivity. The original two-stage model is decomposed into a construction master problem and an operation optimization subproblem, and then being iteratively solved using the generalized Benders decomposition algorithm. The effectiveness of the proposed approach is demonstrated on a modified IEEE RTS-79 system and a practical large-scale system. [ABSTRACT FROM AUTHOR]