FIELD: electrical engineering.
SUBSTANCE: scope of application relates to electrical engineering, namely: to devices intended for measurement of capacitance current of earth fault in electric distribution networks 6–35 kV. Method for determining capacitance current of earth fault in electric networks with compensated neutral 6–35 kV installed in neutral by arc-suppression reactors (ASR) by compensation current control by change of non-magnetic core gap with unknown current adjustment parameters. Essence of the disclosed solution lies in the fact that the capacitive current is calculated by measuring the detuning at two values of the capacitive mains current: the corresponding resonant tuning of the ASR and in non-compensation mode with parallel connection with working winding or its secondary circuit capacitor with known value of capacitor current added to it. Monitoring of zero sequence circuit detuning (SCD) of the network is performed using frequencies of natural oscillations of the SCD in the resonance region and with connection to the circuit of additional electric capacity, obtained by acting on pulse current circuit by means of one of secondary windings of ASR.
EFFECT: technical result when implementing the declared solution is reduced duration of the conducted measurement procedure, high accuracy of calculating capacitance current at low power indices of the disturbance source of the circuit, does not require switching on the plunger drive of the arc-suppression coil in the process of measurements and increases service life of the equipment.
1 cl, 1 dwg
