| 摘要 |
<p>The invention concerns a protection device for electrical components included in electrical power supply networks, such as sections of lines, busbars transformers, and the like, preferably such very quick-operating protections which are based on measuring the extension of the transient waves in the components. The protection device has circuit arrangements for achieving such an alteration of the functional value of the intact phases, in connection with single pole tripping after the occurrence of a single-phase fault, that triple pole tripping is prevented without causing the protection device to be fully blocked. The device comprises a wave detector for indication of faults occurring, a level detector for determining the functional level of the protection, and a phase selector having one output per phase, on which the tripping signals of the protection occur, the level detector being switchable between a normal functional value and a second, preferably higher functional value.</p> |
