DEVICE FOR ELECTRIC CURRENT PROTECTION OF ELECTRIC CIRCUITS AGAINST SINGLE-PHASE EARTH FAULTS

摘要

FIELD: electrical engineering.;SUBSTANCE: invention relates to electrical engineering and can be used for relay protection in 6–35 kV electric mains operating with insulated or resistive-earthed neutral at single-phase earth faults via transient resistances. Summary: automatic setting current correction device is connected to the module of automatic adaptive correction of setting current, containing a set of ambient environment control sensors connected to the first microcontroller, which determines primary parameters of long line and phase speed of pulse propagation along the line. Output of the first microcontroller is connected to a reflectometer which determines the distance to the accident site. Output of the reflectometer is connected to the second microcontroller, the input of which receives values of the primary parameters of the line. Output of the second microcontroller is connected to the module for automatic adaptive correction of setting current.;EFFECT: increased accuracy and speed of protection operation at short-circuit, reduced number of arbitrary protection actuation.;1 cl, 1 dwg