1. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 1 Optimal Accommodation of DG Dr Gareth Harrison Dr Robin Wallace University of Edinburgh, UK

2. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 2 Overview Planning need Planning tool outline Example of operation Update and future work Adequacy/cost effectiveness of available tools

3. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 3 Planning Need Voltage rise major issue in rural areas Mitigation techniques exist –Often expensive One alternative is to avoid or limit the need for mitigation in the first place –Indicate where capacity is available Must identify where capacity exists

4. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 4 Planning Tool Transmission level studies –Distribution level more onerous Various methods applied (GAs, etc.) –DG placement for min loss/investment costs Aim here to maximise DG capacity –Optimal power flow Implemented with PSS/E and bespoke GUI

5. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 5 ‘Reverse Load-ability’ Standard PV generator models inadequate Steady state model of DG as negative load Use load shedding minimisation algorithm to add negative load –maximise power injections Termed ‘reverse load-ability’

6. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 6 180 kW DG on feeder 500 kW DG on feeder Low demand profile Simple 11 kV Feeder

7. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 7 Update Original simplifications removed –fixed taps; lack of traditional generation Transformer voltage control issue –need to mimic voltage Applied to much larger system Consistent and logical results

8. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 8 Extensive Network

9. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 9 Future Work Project due to end in September 2003 Other aspects –Economic analysis –Development of capacity expansion strategies Beyond September 2003 –Adapt approach for fault level constraints

10. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 10 Adequacy of Current Tools Not aware of commercial software tool –Academic tools address some aspects of need Recently developed tools address the need Assessment computationally intensive –Need for re-evaluation with new connections – Move to stochastic standards/planning?

11. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 11 Cost Effectiveness Costs arise from –setup/integration, input/evaluation, computation and inaccuracy Tool requirements –Easy to use, fast, accurate and can be integrated effectively Some current tools likely to meet criteria

12. HARRISON UK Author Session 4 – Block 4 – Question 9 Barcelona 12-15 May 2003 12 Other UoE papers at CIRED This work is part of a larger ongoing programme at the University of Edinburgh Papers presented at CIRED –4.44 - Intelligent generator control –4.62 - Domestic CHP –4.63 - Optimal accommodation of DG