METHOD OF DETERMINING SINGLE-PHASE FAULT TO EARTH ON OVERHEAD TRANSMISSION LINES WITH INSULATED NEUTRAL VOLTAGE 6-35 kV Russian patent published in 2020 - IPC G01R31/08 

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and power engineering and can be used for diagnosing single-phase faults to earth on overhead lines in distribution networks with voltage of 6–35 kV with insulated mode of neutral operation. For each power transmission line in the storage unit of reference voltage values of transient processes during faults, instantaneous voltage values are stored, which correspond to the duration of single-phase fault to earth on the power line at different points. Phase voltages are controlled at single-phase faults to earth of separate lines. For this purpose, phase voltages are reduced by voltage dividers and analog voltage values are sequentially transmitted to high-pass filters and analogue-to-digital converters, which perform digitization of instant values of phase voltages and transmit the digital code to correlation analysis units. Simultaneously, units for storage of instantaneous values of voltage transient processes in turns are transmitted successively to correlation analysis units voltage standards for calculation of mutually correlation functions. At maximum value of maximums of mutual-correlation functions at single-phase fault to earth above other corresponding correlation analysis unit generates alarm signal with information on emergency line and point on line, in which single-phase fault to earth occurred.

EFFECT: improving localization accuracy of single-phase fault to earth.

5 cl, 4 dwg