Power Systems Lab · 18 modules · all computed in your browser
COMTRADE viewer
Sample events, cursor DFT phasors, 2nd harmonic, your own files.
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Power Systems Lab · 18 modules · all computed in your browser
Sample events, cursor DFT phasors, 2nd harmonic, your own files.
Loading module…
COMTRADE-style event viewer
Synthetic A-G line fault · 32 samples/cycle
Voltages
Currents
VA rms
28.2 kV ∠-0°
VB rms
93.9 kV ∠-120°
VC rms
93.9 kV ∠120°
IA rms
5620.0 A ∠-85°
IB rms
353.6 A ∠-143°
IC rms
353.6 A ∠97°
IA 2nd harm.
0 %
IB 2nd harm.
0 %
IC 2nd harm.
0 %
Learn it
An event record is the relay’s flight recorder: sampled voltages and currents plus digital channels (trips, breaker status) around a disturbance. Reading one well means telling apart the prefault load, fault inception, the DC offset decay, the trip, the breaker opening and the arc extinction.
Relays don’t look at the raw waveform. They compute a phasor over a sliding one-cycle window, which is exactly what the cursor does here. Slide it across fault inception and watch the phasor “ramp” over one cycle. That is the inherent filter delay.
Quiz · 0/3
1. Why does the computed phasor lag the waveform change by about one cycle?
2. Which signature points to inrush rather than a fault?
3. In the CT-saturation event, the current waveform…