Are you talking about this function diagram? If it is this diagram, the basis for determining the function parameters, which is what you call the standard curve, is the proportion of wind power installed capacity to the total capacity of other power sources.
This is determined by the impact of wind power off-grid on the entire network, and also by the performance of the grid-connected wind turbines. For example, whether the excitation system of the fan is permanent magnet or other, and the performance parameters of the converter are factors that affect this curve.
What I said may not be accurate, and you are welcome to discuss it.