A Global Sensitivity-based Identification of Key Factors on Stability of Power Grid with Multi-outfeed HVDC

Multi-outfeed configuration of high voltage direct current (HVDC) links is being increasingly developed in Chinas power source grids. Although CIGRE has provided many indices for assessing the security of asynchronous interconnected power grids, massive stochastic renewables significantly induce challenges for dispatchers in determining how numerous operational variables affect these indices, such that it can be difficult to plan a power grid that well bears multi-outfeed HVDCs. To solve this problem, an index integration-combined global sensitivity analysis (GSA) method is proposed. First, several indices that quantify voltage stability, frequency stability, and transient stability are provided. These indices are then fused by the proposed entropy weight-fuzzy analytic hierarchy process (EWF-AHP) method, such that the original massive indices are reduced to only one. Finally, a Gaussian process-based GSA method is applied to analyze the sensitivity of the syncretic index versus the uncertainty variables. The collected sensitivity information can further inform the planning strategies for multi-HVDC outfeed power grids. A real-world case in Southwest China proved the effectiveness of the proposed framework, and implied the potential of the method for tuning or planning operational modes.