System and method for estimating active power capacity based on inverter resources

The invention relates to a system and method for estimating an active power capacity of an inverter-based resource, and specifically, a method for controlling an inverter-based resource (IBR) having a power converter and a generator connected to a power grid includes determining an available active power of the power grid. The method further includes determining an available active power of the IBR based on an effect of the speed of the generator and the rating. Further, the method includes determining a minimum available active power based on the available active power of the power grid and the available active power of the IBR. Further, the method includes determining an active power limit change for the IBR based on one or more thermal tolerances of the IBR. In addition, the method includes determining an active power estimate based on the minimum available active power and the active power limit variation. The method further includes providing the active power estimate to a supervisory controller for cont