Phase-Phase fault detection
Phase-Phase fault detection
(OP)
Can any of yous guys offhand, suggest a solution to detect phase-phase faults on a Dd0 system, where the lowest fault current due to arcing resistance, no inductive contribution is lower than the actual load current at that point? Obviously you cant simply set the current pickup on a standard IDMT at this lowest prospective fault current as normal operating currents would set it off?!?! So basically im stumped what direction to go in.
Many thanks in advance for any input no matter how small.
Many thanks in advance for any input no matter how small.






RE: Phase-Phase fault detection
RE: Phase-Phase fault detection
RE: Phase-Phase fault detection
Have a look at the website of SEL. They have useful information regarding detecting faults with negative sequence currents.
Normal loaded systems (balanced) just have positive sequence currents. Phase-phase faults consist out of positive and negative sequence currents. Because there is no negative sequence currents in a balanced system, you can set the setting normally at 1% or 2% of the possitive sequence current setting.
www.selinc.com
Regards
Ralph