Method and device for calculating photovoltaic grid-connected critical capacity and medium

The invention discloses a photovoltaic grid-connected critical capacity calculation method and device and a medium. The method comprises the following steps: constructing a first reactive power calculation model absorbed by a sending-end converter according to parameter data of a large-scale photovoltaic alternating current collection direct current sending-out system, a second reactive power calculation model for the AC main network to feed in AC wireless and a third reactive power calculation model for the photovoltaic power generation AC collection line to feed in the sending end conversion bus; according to the first reactive power calculation model, the second reactive power calculation model and the third reactive power calculation model, constructing a sending end converter bus static voltage regulation sensitivity reciprocal calculation model; a critical capacity calculation model of the photovoltaic power station is constructed according to the sending end converter bus static voltage regulation sens