Patent ID: 11942774
Assignee: EATON INTELLIGENT POWER LIMITED
Field: Measurement (Instruments)
Classification: CPC H  G | IPC G  H

Claim 7:
8. An arc fault detector, with the arc fault detector comprising:
a first electric line;
a first sensor configured to: monitor an electric current or voltage spectrum in the first electric line and output a broadband measurement signal,
a signal-pattern-analyser configured to: compare the broadband measurement signal with at least a first predefined arc pattern, and output a first arc-detection-signal on a first output in a case where the broadband measurement signal matches the arc pattern;
a slew-rate-detector configured to: determine a slew rate of the electric current in the first electric line, compare the determined slew rate with a threshold slew rate, and output a slew-rate-detection-signal on a second output in a case where the determined slew rate is higher than the threshold slew rate;
an envelope-step-detector configured to determine a change of an envelope-value of at least a predefined frequency band of the broadband measurement signal within a predefined timespan, the envelope-step-detector being further configured to output an envelope-step-detection-signal on a third output in a case that the determined change is higher than a threshold change;
a first controller connected to the second output and the third output, the first controller being configured to output a second arc-detection-signal on a fourth output in a case where the first controller receives the slew-rate detection signal and the frequency-detection-signal within a first predefined detection-time-window; and
a second controller connected to the first output and the fourth output, the second controller being configured to output a trigger signal on a trigger output in a case where the second controller receives the first arc-detection-signal and the second arc-detection-signal for at least a defined total time within a second predefined detection-time-window,
wherein the arc fault detector further comprises a RMS-current-measurement-unit, with a fifth output of the RMS-current-measurement-unit being connected to the second controller, and that the second controller is adapted to adjust the total time depending on the RMS value of the current.