Transcript Grid Connection Issues

Grid Connection Issues
Micro Hydro Projects
Rachel Hodges
Where, and how suitable is the ‘Grid’?
• Tend to be in
awkward locations
• Consider during
initial feasibility
• Can be a go/no-go
decision maker
Look at:
Distance
Single / 3 Phase
Voltage
Local Loads
Switchgear and Ratings
Accommodation
Synchronising
• Synchronous Machine
– Need inverters and controllers to match frequency of the grid
– Need to consider harmonic content
– Can operate in islanded system
• Asynchronous or Induction Machines
– Automatically match frequency of the grid
– Need power factor control (switchable capacitors or DFIG)
G83 versus G59
G83
G59
• For up to 16A per phase
(6kW at Low Voltage)
• Equipment G83
Certification
• Notify the Distribution
Network Operator (DNO)
• For up to 5MW at 20kV
• Connection application,
connection offer and
witness testing required.
Connection Application
• DNO will look at:
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Transformer and connection capacity
Abnormal feed conditions
Fault Levels
Voltage Rise (P28)
Voltage Step Change, Flicker and
Harmonics (G5/4)
– Loss of Mains (Islanding) Protection and
Earthing (G59)
Connection Offer
• Can take up to 90 days
• Connection offer will indicate:
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Non-contestable work and costs (to be undertaken by DNO)
Contestable work (undertaken by accredited 3rd party or DNO)
Constraints
Timeframes
G59 Protection
• Under and Over Voltage
• Under and Over Frequency
• Loss of Mains (ROCOF, Vector Shift,
Intertripping)
Metering
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ROCs
Import / Export
Export MPAN from Supplier
Power Purchase Agreements
Benefits of Onsite Generation
Grid Connection Issues
Micro Hydro Projects
Rachel Hodges