Method for evaluating frequency stability of power system

The invention discloses a method for evaluating frequency stability of a power system, which comprises the following steps of: converting model parameters of speed regulators and prime movers of generators into equivalent models with similar dynamic performance according to frequency-mechanical power response characteristics under disturbance by reading simulation file data of the power system; determining parameters of the equivalent model by using a least square method; grouping the generators according to the equivalent model parameters of all the generators after equivalence, wherein one group of generators share the same equivalent model, and the number of the generators in the system is reduced; and finally, establishing an average system frequency model according to the equivalent model parameters of each group of generators after equivalence, obtaining a system frequency deviation analytical formula after disturbance, determining the maximum deviation frequency and the maximum frequency change rate of