Power grid frequency fitting method and system considering wind power low-voltage ride through difference

The invention discloses a power grid frequency fitting method considering wind power low-voltage crossing difference, and the method comprises the steps: obtaining an original file containing a wind turbine generator operation result under an anticipated fault, extracting the data in the original file to obtain a low-voltage crossing disturbance power amount, obtaining a frequency response optimization model of a new energy power system according to the parameter data of a wind turbine generator, and carrying out the low-voltage crossing disturbance power amount. Performing parameter identification according to the frequency response optimization model to obtain a transfer function of the frequency response optimization model, performing calculation according to parameter data of the wind turbine generator to obtain single-machine equivalent model parameters of the low-penetration disturbance power, solving an analytic expression of the low-penetration disturbance power, and taking the analytic expression of