1HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

Optimal Accommodation of DG

Dr Gareth Harrison

Dr Robin WallaceUniversity of Edinburgh, UK

2HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

Overview

• Planning need

• Planning tool outline

• Example of operation

• Update and future work

• Adequacy/cost effectiveness of available tools

3HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

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

4HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

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

5HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

‘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’

6HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

180 kW DG on feeder

500 kW DG on feeder

Low demand profile

Simple 11 kV Feeder

7HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

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

8HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

Extensive Network

9HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

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

10HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

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?

11HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

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

12HARRISON UK Author Session 4 – Block 4 – Question 9

Barcelona 12-15 May 2003

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