The invention discloses a controller and method for simulating the active
power frequency of a double-fed
induction generator (DFIG) in combination with
inertia and over speed. The controller comprises a
frequency deviation detecting module, a blocking module, a regulating variable setting module, a time
delay module and a speed protecting module which are connected in sequence, wherein a real-time grid frequency
signal and a frequency setting value are respectively input in the
frequency deviation detecting module to obtain the
frequency deviation signal of the grid at that time; the frequency deviation
signal enters the regulating variable setting module through the blocking module, and the regulating variable setting module obtains a speed regulating variable according to the frequency deviation signal; and the speed protecting module enables the DFIG unit to exit
frequency modulation under an abnormal speed condition, and can put into the
frequency modulation again after time
delay for a period of time. The controller has the beneficial effects that large-scale double-fed
wind power integration takes the place of a conventional synchronous generator to cause that the
system inertia is reduced and thus the transient stability of
system frequency is worsened, and the comprehensive frequency controller provided by the invention can effectively solve the problem.