Sensitivity Analysis Based VSC-HVDC Power Emergency Control for Transmission Overloading

To prevent potential overloading caused by transient power flow shifts on transmission networks after fault-driven line disconnections, this paper proposes a Sensitivity analysis based VSC-HVDC power Emergency Control for transmission Overloading (SECO). By employing a sensitivity matrix to identify the sensitivity of DC network powers over AC network powers, VSC-HVDC power flow can be rapidly adjusted to address AC network overloading in a most effective manner. For case study, after the disconnection of an AC line in the IEEE39 system, the SECO method is employed to calculate the power sensitivity of two VSC-HVDC lines to each overloading line. Subsequently, adjustments to the VSC-HVDC network powers are made based on this sensitivity, aiming to restore the overloading AC lines to their normal operating state. The feasibility of the proposed method is validated in the IEEE39 bus system, proving that this approach can enhance the operational security of the power system via rapid DC power responses.