A method for automatically compensating a single-phase earth fault current in a network with an arc suppression reactor in neutral

摘要

FIELD: electrical equipment.;SUBSTANCE: use: in the field of electrical engineering and power engineering. According to the method, an artificial potential is created on the neutral by injecting the source current into the network zero circuit, measuring the parameters of the zero sequence circuit and adjusting the arc suppression reactor, and from the moment of occurrence of fault to earth, the residual current at the fault to earth location is determined, compared with the threshold level, source is controlled and its current is regulated to the full compensation of the single-phase fault to earth current. Residual current is determined by summing individual current components that occur at the fault to earth location. First component of the residual current is determined by calculating the product of the conductivity of a network zero circuit contour, measured in the period preceding the moment of occurrence of a fault to earth, the voltage of the damaged phase, measured with respect to the neutral of the network. Second component of the residual current is determined by calculating the product of the conductivity of the network zero contour circuit, before the moment of fault to earth occurrence, to the voltage of the neutral relative to the earth measured during the same period. When the resultant residual current exceeds a given threshold level, the source current is set proportional to the resulting residual current, and if the resultant residual current does not exceed a given threshold level, then the source current is set to zero.;EFFECT: technical result is higher efficiency of compensation of single-phase fault to earth currents, and, as a consequence, improving electric power supply reliability of consumers.;5 cl, 1 dwg