COMPACT SECONDARY SUBSTATION COMPRISING AN ARCING FAULT PROTECTION SYSTEM, A METHOD FOR ARCING FAULT PROTECTION IN A COMPACT SECONDARY SUBSTATION, AND A CONTROL UNIT FOR PERFORMING THE METHOD

摘要

The present invention relates to a Compact Secondary Substation comprising a fault protection system and a method for fault protection in Compact Secondary Substations (CSS). The CSS comprises a Ring Main Unit (RMU), a transformer and a Low Voltage (LV) switchgear.The object of the invention is to fault protect a secondary switchgear, a further object of the invention is in fault situations to bring the secondary switchgear back in operation as soon as possible. The objects can be fulfilled by a system where the CSS comprises a number of detectors (114, 116, 118, 126, 128, 134), which detectors can be placed at least in one of the RMU, the transformer or in the LV switchgear, which detectors can be connected to a control unit (106), which control unit by fault detection by the detectors can activate a fast operating switch (112) for grounding. By using the fast operating grounding switch (112) and controlling this on the basis of the detectors placed inside the CSS, an active arc fault protection is achieved. The control unit (106) also controls the fast operating grounding switch (112) so that it works as a working grounding switch.