Method and system for calculating minimum startup scale of high-proportion new energy access power grid

The invention discloses a minimum starting scale calculation method and system for a high-proportion new energy access power grid under voltage stability constraint. The method comprises the steps that the starting capacity of a synchronous generator set and the starting capacity of a new energy set in a multi-direct-current feed-in system are determined; determining a node admittance matrix of the multi-direct-current feed-in system based on a power grid equivalent model; performing inversion on the node admittance matrix to obtain a node impedance matrix of the multi-direct-current feed-in system; according to the node impedance matrix, respectively calculating equivalent capacities of the synchronous generator set and the new energy unit at a voltage weak point, and a new energy equivalent permeability of an equivalent unit; according to the equivalent capacities of the synchronous generator set and the new energy unit, obtaining the parallel equivalent impedance of the equivalent unit of any voltage weak