Patent ID: 11043803

Abstract:
The present disclosure relates to generating reference signals for distance and directional elements in power systems. For example, an intelligent electronic device (IED) may receive A-phase, B-phase, and C-phase electrical measurements of a power system. The IED may transform the A-phase, B-phase, and C-phase measurements to a d-component, a q-component, and a 0-component. The IED may include an adaptive notch filter that reduces or eliminates a double frequency component that may be present when step changes of frequency and/or amplitude occur and/or when the A-phase, B-phase, and C-phase measurements have different amplitudes. By reducing the double frequency component, the IED may generate a more accurate ω which may allow for more accurately tracking changes to the polarizing source. Further, the IED may separately add inertia to the estimated angular frequency used in generating a reference signal.