Method and system for determining regulation and control sensitivity of PQ node voltage stability index of AC-DC power grid

The invention provides a method and system for determining the regulation and control sensitivity of a PQ node voltage stability index of an AC-DC power grid. The method comprises the steps: solving a node dynamic equivalent impedance in a specified load growth direction and a specified DC system control mode based on a system dynamic equivalent impedance solving method, and acquiring a Thevenin equivalent parameter of a PQ node; on the basis of the obtained Thevenin equivalent parameters of the PQ nodes, simplifying the AC-DC power grid into a two-node system corresponding to the equivalent parameters, determining a voltage stability margin expression of the nodes, and then deducing a sensitivity relational expression of regulation and control measures to equivalent impedance in the stability margin expression; eliminating an equivalent potential modulus value in the voltage stability margin expression to obtain a new expression; and finally, conducting deriving based on the expression of the voltage stabili