john millar – finland – rt.1a/5a
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Distribution Network Planning and Underground Cables Keeping overview while attending to detail. John MILLAR – Finland – RT.1a/5a. …with much appreciated help from, among others: Prof. Matti Lehtonen and Eero Saarijärvi. My research fields. Ampacity of underground cables - PowerPoint PPT PresentationTRANSCRIPT
Frankfurt (Germany), 6-9 June 2011
John MILLAR – Finland – RT.1a/5a
Distribution Network Planning and Underground Cables
Keeping overview while attending to detail
…with much appreciated help from, among others: Prof. Matti Lehtonen and Eero Saarijärvi
Frankfurt (Germany), 6-9 June 2011
My research fields
Ampacity of underground cables Practical investigations of their thermal
environment Development of real-time algorithms
Network planning algorithm MV, LV and MV-LV…
Frankfurt (Germany), 6-9 June 2011
Underground cable rating
Suggest steady-state for planning The future is hard to predict…
Cyclic rating for existing, but note: Needs thorough knowledge of installed conditions Must consider:
Moisture migration External heat sources Condition of existing cables
Frankfurt (Germany), 6-9 June 2011
Cyclic vs. Steady-state rating forexisting MV cables
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65 °C steady-state current limit
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stur
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90 °C steady-state current limit
65 °C:• steady-state rating: 340A• cyclic rating: 385 A
90 °C:• steady-state rating: 382 A• cyclic rating: 462 A
Frankfurt (Germany), 6-9 June 2011
Cables: Installation challenges
Crowding of underground services
Duct bank and tube installation ratings more challenging
Charging current >> load currents for long rural cable connections
Frankfurt (Germany), 6-9 June 2011
Distribution network planning
Automating the laborious task of trial and error planning
An algorithm that deals with real networks and realistic planning issues in reasonable computation times
Trying to keep up with contemporary developments...
Frankfurt (Germany), 6-9 June 2011
VOH_MV
‘Optimally’ routes lines between fixed primary and secondary substations, i.e. plans the MV network.• Optimal or full switching – 3 levels• Optimal or full backup connections
between main feeders• Existing network consideration and
upgrade times• User-preferred network
Frankfurt (Germany), 6-9 June 2011
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VOH_MV, e.g.:
Frankfurt (Germany), 6-9 June 2011
VOH_MV_LV
Starts with LV customers and primary substation positions
‘Optimises’, according to various planning philosophies: secondary substations (no. and positions) connection (cable) boxes (no. and positions) And, of course the MV and LV network
routing – switches – backup
Frankfurt (Germany), 6-9 June 2011
VOH_MV_LVOne approach
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LV customers
PrimarySubstations
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Frankfurt (Germany), 6-9 June 2011
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VOH_MV_LVAnother approach
Frankfurt (Germany), 6-9 June 2011
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VOH_MV_LVand another approach
Frankfurt (Germany), 6-9 June 2011
VOH_MV_LVand finally...
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Frankfurt (Germany), 6-9 June 2011
Contemporary developments
mmm... We know that this algorithm should be able to handle distributed generation – coming ‘soon’! What else?
Many thanks!