General Electric Company
Dual-frequency filter for distinguishing between different types of grid events

Abstract:

A method for controlling a dual-fed induction generator (DFIG) connected to a power grid in response to a high-voltage grid event includes receiving, via a controller, a frequency signal of the power grid. The method also includes filtering the frequency signal via a filtering assembly so as to determine whether certain types of grid conditions are present in the power grid. The filtering assembly includes a first filter connected in parallel with a second filter. The first filter has a bandwidth that is greater than the second filter. Further, the method also includes comparing output signals of the first and second filters of the filtering assembly to one or more frequency thresholds. Moreover, the method includes controlling the DFIG based on the comparison.