Transient dominant instability form discrimination method and system and readable storage medium

The invention discloses a transient dominant instability form discrimination method and system and a readable storage medium. The method comprises the steps of obtaining a voltage phasor of a lowest node of a whole network voltage; judging whether a dominant instability form judgment algorithm is started or not according to the voltage phasor of the lowest node of the whole network voltage, if yes, entering the next step, and if not, obtaining the voltage phasor of the lowest node of the whole network voltage at the next moment; calculating a dominant instability form combination criterion, and obtaining a dominant instability form discrimination result by using the dominant instability form combination criterion; and generating an emergency control strategy according to the relationship between the voltage amplitude of the lowest node of the whole network voltage and the active splitting control threshold value when the dominant instability form judgment result is obtained. The method only needs single-ended