Assessment method and system for voltage supporting capability of multi-DC-feed AC power grid

The invention discloses an assessment method and system for the voltage supporting capability of a multi-DC-feed AC power grid, and the method enables the voltage supporting capability of the multi-DC-feed AC power grid to be reflected by the capability of simultaneous increase of active power of an AC system for supporting a multi-DC power transmission line. Through the setting of an incidence matrix for the increase of a current constant value of the multi-DC power transmission line, the margin between the maximum value of the increase of DC power and a rated value is calculated, thereby forming quantitative indexes for the assessment of the voltage supporting capability of the multi-DC-feed AC power grid. The method and system are clear in physical concepts, is high in adaptability, and is good in prospects of popularization and application.