| 摘要 |
<p>Partial (4) and total (3) arc discharges on transmission lines, e.g. on insulators (2) are detected in order to activate alarm and trip functions. It is achieved by detecting the hf oscillations set up by the spark and using these as an alarm or trip signal. A suitable circuit isolator (5) e.g. an opto-electronic circuit, decouples the HV line (1) from the protection circuit. A filter unit (6) eliminates the standing hf components due to corona or line carrier signalling, and passes any genuine arc signal to a level detector (7). If the arcing passes a predetermined level a circuit is made to give alarm and/or trip the affected line.</p> |
