Arc fault detection device with wideband sensor

A method for operating an arc fault detection device including a first terminal and a second terminal configured to connect the arc fault detection device to a conductor of an electric line;

• a sensor configured to generate a sensor signal from a current through the electric line;
• a circuit breaker configured to interrupt the electric line;
• and
• a controller configured to detect the arc fault from the sensor signal;
• wherein the sensor comprises an inductor connected to the first terminal and the second terminal and a capacitor connected in parallel with the inductor,
• wherein the inductor and the capacitor form a resonant circuit with a resonance frequency, the resonance frequency determining an impedance behavior of the resonant circuit,
• wherein the inductor and a capacitance of the capacitor are chosen such that the impedance behavior of the resonant circuit corresponds to a desired impedance behavior over a relevant frequency range of the current through the electric line, and
• wherein the inductor is a magnetic actuator configured to operate the circuit breaker, the method comprising:
• receiving the sensor signal from the sensor;
• determining from the sensor signal whether the electric line has an arc fault or not;
• when the arc fault is detected:
• generating a trip signal for interrupting the electric line.

An arc fault detection device for detecting an arc fault in an electric line, the arc fault detection device comprising:

• a first terminal and a second terminal configured to connect the arc fault detection device to a conductor of the electric line;
• a sensor configured to generate a sensor signal from a current through the electric line;
• and
• a controller configured to detect the arc fault from the sensor signal,
• wherein the sensor comprises an inductor connected to the first terminal and the second terminal and a capacitor connected in parallel with the inductor,
• wherein the inductor and the capacitor form a resonant circuit with a resonance frequency, the resonance frequency determining an impedance behavior of the resonant circuit,
• wherein the inductor and the capacitor are chosen such that the impedance behavior of the resonant circuit corresponds to a desired impedance behavior over a relevant frequency range of the current through the electric line,
• wherein the sensor further comprises a protection circuit configured to limit an output current and/or output voltage of the sensor, and
• wherein an input of the controller is connected via the protection circuit to the resonant circuit.