Monitoring solutions for electrical systems

A monitoring device for monitoring an operating state of a circuit breaker electrically connected to an electric line, wherein the monitoring device is configured to:

• inject a first signal at a first point of the electric line, wherein the first signal has a predefined frequency content and a predefined frequency band and is injected during an injection time interval having a predefined time duration;
• detect a second signal at a second point of the electric line, wherein the second signal is detected during a detection time interval including at least partially the injection time interval;
• process a first portion of the second signal, which refers to a first portion of the detection time interval during which the first signal is injected, to calculate a first signal value indicative of the signal power of the second signal in the frequency band of the first signal, during the first portion of the detection time interval;
• and
• process a second portion of the second signal, which refers to a second portion of the detection time interval during which the first signal is not injected, to calculate a second signal value indicative of the signal power of the second signal in the frequency band of the first signal, during the second portion of the detection time interval.

A low-voltage electrical system comprising:

• an electric line;
• a circuit breaker electrically connected between a first line section and a second line section of the electric line;
• and
• a monitoring device configured to monitor an operating state of the circuit breaker, wherein the monitoring device is electrically connected to the electric line at a first point of the electric line and at a second point of the electric line, and the monitoring device is configured to:
• inject a first signal at a first point of the electric line, wherein the first signal has a predefined frequency content and a predefined frequency band and is injected during an injection time interval having a predefined time duration;
• detect a second signal at a second point of the electric line, wherein the second signal is detected during a detection time interval including at least partially the injection time interval;
• process a first portion of the second signal, which refers to a first portion of the detection time interval during which the first signal is injected, to calculate a first signal value indicative of the signal power of the second signal in the frequency band of the first signal, during the first portion of the detection time interval;
• and
• process a second portion of the second signal, which refers to a second portion of the detection time interval during which the first signal is not injected, to calculate a second signal value indicative of the signal power of the second signal in the frequency band of the first signal, during the second portion of the detection time interval.