METHOD selective protection against earth faults in the electrical network low-current ground fault

摘要

1. A method of determining the faulty feeder for single-phase earth fault in a network with low current earth faults, wherein the measured zero sequence currents of all outgoing connections, current connections are selected in excess of the minimum specified level, the phase shifts are determined by the zero-sequence currents of all outgoing connections relative to the base signal is detected signal with minimal phase shift relative to the base signal, a decision is made that the feeder in which the current imee minimum phase shift is damaged, characterized in that the instantaneous values ​​of the summed zero-sequence currents of all outgoing connections to and from this sum is formed signal.2 base. A method of determining the faulty feeder for single-phase earth fault in a network with low current earth faults, characterized in that the presence in the network of the grounding reactor, a resistor, or a combination thereof is measured by the current in the grounding circuit and the current in the grounding circuit is adopted as the reference signal.