METHOD TO DETECT DISTANCE TO AREA OF DAMAGE ON POWER TRANSMISSION LINE Russian patent published in 2013 - IPC G01R31/08 

FIELD: electrical engineering.

SUBSTANCE: one measures currents and voltages at each end of the lines, isolates the alarm signal from the measured currents and voltages, calculates the isolated alarm signal excess factor within a sliding time window, compares the calculated excess factor to the threshold value, registers the threshold crossing moment with the help of a satellite navigation system and calculates the distance from the area of damage by the difference between the threshold crossing moments registered at the line ends. The method is implemented with the help of a device containing phase current and voltage metres the outputs whereof are connected to the unit 1 emitting an alarm signal from the measured phase currents and voltages. Connected to unit 1 output is unit 2 calculating the excess factor within a sliding time window. Connected to unit 2 output is one input of the comparator 3 comparing the excess factor as calculated by unit 2 with the threshold value set at the other input of comparator 3 by unit 4. Comparator 3 output is connected to the capture input of timer 5. Connected to timer 5 inverting input is the output of unit 6 receiving timing pulse from the satellite navigation system. The output of timer 5 is connected to communication unit 7 that transmits the time of alarm signal wave front arrival at the corresponding end of the power transmission line to the dispatcher console.

EFFECT: enhanced sensibility and accuracy of detection of the area of damage on power transmission lines due to more accurate isolation of alarm transitory process wave front from the aggregate of background noises obeying the distribution law.

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