| 摘要 |
<p>The feeders in to and out of an electrical distribution component, e.g. a substation, are monitored for voltages and/or currents indicative of a fault. A monitoring device 21 is connected to each outgoing feeder 13 connected to a busbar 12 of the component and supplying a load 14. A further monitoring device 21 may be connected to the incoming feeder 11. A prospective fault level is calculated based on the magnitudes of detected disturbances in the voltages or currents in the feeders. Disturbances at the fundamental and harmonic frequencies may be measured. Averaged time profiles of variations in the voltages or currents may be used to detect infeed faults. The fault level calculated may be used to ensure that the fault current released in the event of a short circuit can be handled by the breakers in the switchgear of the distribution network.</p> |
