Optimal Accommodation of DG

1
Optimal Accommodation of DG

• Dr Gareth Harrison
• Dr Robin Wallace
• University of Edinburgh, UK

2
Overview

• Planning need
• Planning tool outline
• Example of operation
• Update and future work
• Adequacy/cost effectiveness of available tools

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
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
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
Simple 11 kV Feeder
500 kW DG on feeder
180 kW DG on feeder
Low demand profile
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
Extensive Network
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
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
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
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