| 摘要 |
The present disclosure relates to a method and a corresponding monitoring device (35) for detecting earth faults in a power distribution system, where a busbar (7) feeds power to a plurality of feeding loops, and a distribution grid feeds power to the busbar via a transformer (3). The secondary side of the transformer (3) is connected to earth via a Petersen coil (21). The Petersen coil voltage and the feeding loop currents are measured, and the first order derivative of the Peterson coil voltage is determined. This derivative is correlated with each of the feeding loop currents, and the feeding loop with the highest correlation over a predetermined time is detected as having an earth fault. This provides a simple but yet reliable scheme for detecting an intermittent earth fault, such that measures can be taken to replace a damaged cable before it breaks down permanently.
|
