Connecting to the Grid: Active Network Management on Orkney

1
Connecting to the Grid Active Network Management
on Orkney

• Graham Ault and Robert Currie
• Advanced Electrical Systems Research Group
• University of Strathclyde

2
Orkney Electrical System

• 6 miles off North-Scotland
• 11,500 customers
• Min/Max demand 8/31MW
• 33kV submarine cables 2 x 20MW import/export
• Existing generation a mix of wind, wave and gas.
• Firm Generation (FG) allocated
• Non-Firm Generation (NFG) allocated
• Generation fully committed
• Reactive compensation equipment installed
  (including DVAR)

3
Orkney Active Network Management Scheme

• Reactive compensation equipment solves almost all
  voltage problems
• Each zone has a thermal limitation on generation
  output at any given time
• Whole Orkney system has a further thermal limit
  on generation output
• Real time control of wind and marine generating
  units based on measurements and control logic.

4
Economics of ANM on Orkney
5
ANM Trial November 2006

• Closed loop control trial to test communications
  and control logic on PLCs
• PLCs operational at Scorradale and existing Wind
  Farm
• Trial outcomes
• Integration of ANM scheme with WT/WF controllers
• Verification of logic control (output regulation,
  loss of comms., local and remote lockout/enable),
  PLC capability, interoperability and
  communications solution
• Measurement of communications and control system
  and generation response times
• Control codes for full ANM scheme in development

6
Orkney ANM Trial - Results

• Output of wind farm regulated below issued
  set-point
• Results of trial feeding directly into the design
  of the full ANM scheme

• Response of Wind Farm observed
• Closed-loop control achieved
• Communications and control logic proven

7
Questions?
Does this demonstration encapsulate the sort of
active management scheme envisaged for future
distribution networks?What are the major
barriers to further exploitation of such schemes?