A measuring device for measuring a signal of interest within a measuring signal is provided. It device comprises a trace determiner, which is adapted to consecutively determine a first stack of traces of the measuring signal, a statistics evaluator, adapted to, after each trace of said first stack of traces is determined by the trace determiner, statistically evaluate if a presence of the signal of interest is detected with a first pre-set degree of certainty, wherein the trace determiner is adapted to cease determining said traces of said first stack of traces, when the statistics evaluator has determined that the signal of interest has been detected to the first pre-set degree of certainty. Preferably a parameter determiner is, adapted to determine measuring parameters, based upon the statistical evaluation.

A method, apparatus, and system for disconnecting loads from the electrical grid based on a power line frequency are disclosed. An electricity meter may monitor a power line frequency of a source power line connected to the electricity meter, and in response to determining that the power line frequency is lower than a disconnect threshold frequency, may open an internal switch and disconnect a load side output of the electricity meter from the source power line.

A method, apparatus, and system for disconnecting loads from the electrical grid based on a power line frequency are disclosed. An electricity meter may monitor a power line frequency of a source power line connected to the electricity meter, and in response to determining that the power line frequency is lower than a disconnect threshold frequency, may open an internal switch and disconnect a load side output of the electricity meter from the source power line.

The present disclosure discloses a device and a method for condition monitoring and protection of rotating electrical motors. The device receives measurements of current flowing in a power line connected to the rotating electrical machine. The device extracts a frequency band content containing information representative of condition of rotor bar from the measured current signal using wavelet filters. Further, the device compares the frequency band contents with a predefined threshold value and identifies a condition of the rotor bars. The condition includes damages caused to the rotor bars. Based on the condition, the IED generates one or more status signals (alarm signals or trip signals). The trip signal is provided to a switch connected to the power line to disconnect the rotating electrical machine.

The present disclosure discloses a device and a method for condition monitoring and protection of rotating electrical motors. The device receives measurements of current flowing in a power line connected to the rotating electrical machine. The device extracts a frequency band content containing information representative of condition of rotor bar from the measured current signal using wavelet filters. Further, the device compares the frequency band contents with a predefined threshold value and identifies a condition of the rotor bars. The condition includes damages caused to the rotor bars. Based on the condition, the IED generates one or more status signals (alarm signals or trip signals). The trip signal is provided to a switch connected to the power line to disconnect the rotating electrical machine.

A method, apparatus, and system for disconnecting loads from the electrical grid based on a power line frequency are disclosed. An electricity meter may monitor a power line frequency of a source power line connected to the electricity meter, and in response to determining that the power line frequency is lower than a disconnect threshold frequency, may open an internal switch and disconnect a load side output of the electricity meter from the source power line.

A method, apparatus, and system for disconnecting loads from the electrical grid based on a power line frequency are disclosed. An electricity meter may monitor a power line frequency of a source power line connected to the electricity meter, and in response to determining that the power line frequency is lower than a disconnect threshold frequency, may open an internal switch and disconnect a load side output of the electricity meter from the source power line.

The present invention proposes an arc detector having a multi-band frequency detection function, which divides an arc frequency band using multiple band-pass filters and detects whether or not an arc occurs in each of the divided frequency bands, thereby eliminating switching noise or power supply noise that mainly occurs in a certain frequency band, and consequently increasing the accuracy of arc detection. In addition, the arc detector of the present invention may minimize the use of expensive analog-to-digital converters and increase the accuracy of arc detection through overlapping area detection.

A method, apparatus, and system for disconnecting loads from the electrical grid based on a power line frequency are disclosed. An electricity meter may monitor a power line frequency of a source power line connected to the electricity meter, and in response to determining that the power line frequency is lower than a disconnect threshold frequency, may open an internal switch and disconnect a load side output of the electricity meter from the source power line.

A method, apparatus, and system for disconnecting loads from the electrical grid based on a power line frequency are disclosed. An electricity meter may monitor a power line frequency of a source power line connected to the electricity meter, and in response to determining that the power line frequency is lower than a disconnect threshold frequency, may open an internal switch and disconnect a load side output of the electricity meter from the source power line.