1. 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

2. 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…

3. 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

4. Frankfurt (Germany), 6-9 June 2011 Cyclic vs. Steady-state rating for existing MV cables 65 °C: steady-state rating: 340A cyclic rating: 385 A 90 °C: steady-state rating: 382 A cyclic rating: 462 A

5. 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

6. 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...

7. 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

8. Frankfurt (Germany), 6-9 June 2011 VOH_MV, e.g.:

9. 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

10. Frankfurt (Germany), 6-9 June 2011 VOH_MV_LV One approach LV customers Primary Substations

11. Frankfurt (Germany), 6-9 June 2011 VOH_MV_LV Another approach

12. Frankfurt (Germany), 6-9 June 2011 VOH_MV_LV and another approach

13. Frankfurt (Germany), 6-9 June 2011 VOH_MV_LV and finally...

14. 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!