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Showing posts from June, 2011

Analysis; Damage to a power network from multiple major earthquakes.

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Christchurch has had 3 major, 10 moderate, and around 7000 minor earthquakes and aftershocks at this point in  time. The following is a personal account of the damage based on my  personal experiences and the different side-effects of earthquakes.  I need to stress at this point in time, I am NO geologist, seismologist, or network analyst. So some of this information may not be accurate, it's simply based on my logic as an Electrical Tutor! I apologize in advance if I say anything incorrect, and feel free to post anonymous comments (this has been done, already, thank you!) and correct me. In my opinion there have been four major side-effects of a quake (in Christchurch's  case):  Ground shaking  Liquefaction Lateral spread L andslides/building collapse/rockfalls.  Christchurch did not  experience tsunami related to our own quakes at any stage.  I will cover each category for some systems in the Christchurch distribution network that...

Weeks 19 & 20 - Prebbleton Sub and major quake #3.

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Another fortnight post unfortunately, sorry. Life has become busy since June 13th when we had our 3rd major earthquake. Classed as an aftershock of the Mag 7.1 quake of September 4 2010, this was a Mag 6.3 quake which struck at 2:20pm on June 13th. More damage and liquefaction occurred, and was violent where I was working with my Line crew in Akaroa. I will cover this quake in depth later. Work log:  Tuesday 7th June:  Connect 11kV cables into kiosk for 4x 1MW emergency generators, QEII park. The 4x 1MW diesel generators, QEII park Wednesday 8th June: Connect 11kV cables from 4x 1MW generators into 11kV network, QEII park. 'Tapped into' 11kV cable, QEII park generator supply. Thursday 9th June: Underground-overhead 33kV transition terminations, outside Prebbleton substation. Me doing 33kV termination, Jeff on right. Friday 10th June: Underground-overhead transition terminations, outside Prebbleton substation. The overhead guys connect the 33kV term...

Week 18; The relocation of New Brighton substation to Rawhiti substation.

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This week I observed the finishing of the circuit which is an extension of the original 'emergency circuit' that Orion, Connetics, Independent Lines, and Mainpower constructed to enable relivening of the New Brighton Substation after it was sunk by liquefaction from the M6.3 aftershock of the 22nd February 2011. The extension runs to a new substation in Rawhiti Domain in New Brighton, which did not (and in future, hopefully won't) get much liquefaction. See 'Analysis' for further information. New Brighton substation - a door even I can reach! Work log:  Monday 30th May: Install 66kV poles on Keyes Road. Tuesday 31 May: Start running 66kV conductors, Baker St. Wednesday 1 June: Run 66kV conductors from Baker St to Keyes Rd. Thursday 2 June: JOINTING: Prebbleton substation installation. Prebbleton substation 11 and 33kV cables underneath the Prebbleton substation Friday 3 June: Run 66kV conductors into Rawhiti substation. ANALYSIS: How ...