1 / 10

ALICE DIPOLE Transformer break down

ALICE DIPOLE Transformer break down. G. Le Godec / V. Montabonnet 25/03/2010. ALICE DIPOLE CONVERTER. RPTI.SR2.RBAWV.R2 950V / 6500 A. What happened first?. 25/03/2010 – 13h33 [ Iout =6000A, Vout =630V]: 18 kV MCB: Over current detection Fire detection in SR2 (converter location).

iain
Download Presentation

ALICE DIPOLE Transformer break down

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ALICE DIPOLETransformer break down G. Le Godec / V. Montabonnet 25/03/2010

  2. ALICE DIPOLE CONVERTER • RPTI.SR2.RBAWV.R2 • 950V / 6500 A

  3. What happened first? • 25/03/2010 – 13h33 [Iout=6000A, Vout=630V]: 18 kV MCB: Over current detection • Fire detection in SR2 (converter location).

  4. What happened afterwards? • The MCB over-currentdetectioncut the supply of the entire SR2-EMD4 electrical switchboard, dedicated to the cooling of differentsystems (TCR, cryo plant, SR2 and Point 2 underground LHC converters and DC cables) • As consequences: • stop of the cryo plant • stop of the TCR • stop of converters (surface and underground) in Point2 due to the stop of the water cooling NB: The TCR has been put back in operation on Thursday afternoon.

  5. What is the reason? • Flash over on transformer high voltage windings

  6. 18 kV – Phase W

  7. A few numbers… • Current in the Dipole before the fault:  6000A • Transformer manufacturing date: 2002 but used in operation for • < 1000 hours (to be confirmed by ALICE experiment). • Transformer type Cast-resin • Transformer rating 4.8 MVA • Primary • Voltage: 18 kV • Current: 154 A • Secondary • Voltage: 900 V • Current: 3080 A • Transformer weight: 12.5 Tons

  8. First analysis… • FGC post-mortem: no fault on converter side. • Transformer temperature:  80ºC when the fault occurred (pt100 probes inside each windings). •  This is not a thermal problem (hot spot). The supplier uses Class F insulation (155ºC). • Expertise will be needed with the supplier.

  9. TE/EPC Action • Transformer replacement Thursday afternoon 25/03 until Friday afternoon 26/03 • TE-EPC will need a 2-3 hours slot to test the transformer and the converter (Friday afternoon? Evening?) without LHC beam. EN-EL and Cryo team shall be ready to intervene in case of another unlikely power cut

  10. The future… • Spare situation: no spare transformer for ALICE Dipole / LHCb for the next weeks. • Return of the faulty transformer to the supplier (Analysis and repair). TE-EPC will closely follow the manufacturer analyze to evaluate the risk and to take proper action if required. • Improve the electrical distribution selectivity if possible to avoidtripping the othersystems in case of a power converterfailure

More Related