FIELD: The invention relates to the power generation industry and can be used to determine a feeder with a single-phase arc earth fault in branched three-phase overhead electrical networks (EN) with an isolated neutral grounded through an arc-extinguishing coil or a high-resistance resistor.
SUBSTANCE: transient voltages in feeders are recorded by RCL sensors installed in the identical phases in the middle part of each feeder. For this purpose a serial RC circuit is connected to the wire of each feeder, the second terminal of which is connected to the primary winding of a step-down high-frequency transformer, the second terminal of the primary winding of the transformer is grounded. The voltage on the secondary winding is rectified and integrated using an RC circuit. These voltages on all sensors using time synchronization receivers are simultaneously measured by analog-to-digital converters and transmitted via modems to the power supply center, where, after processing the transient phase voltages and confirming the ground fault, the feeder with the highest signal level on the integrating capacitor is determined. A feeder with a maximum voltage is considered a feeder with a ground fault.
EFFECT: reliability and simplicity of determining a feeder with a single-phase earth fault.
1 cl, 3 dwg
