LV Network Monitoring
Demonstrating the
Possibilities
25 October 2012
Gideon Evans
Introduction
• SSE’s Low Carbon homes
• Can LV Network Monitoring equipment be retrofitted
without taking customers off supply?
Understanding the LV Network
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Capacity
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Current
MDI Information
Demand and Generation
more informed decisions
Performance
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Voltage Limits
Power Factor
Power Quality / Harmonics
more informed decisions
Capacity
Average
Demand
Demand
XX:00
XX:30
Time
Monitoring Equipment
Measuring
Voltage
MDIs
Calculated
data
Storage of
data
Rezap
Fault
management
Transmission
of data
Measuring
Current
Installing Equipment
Measuring Current
• Conventional CTs
– Installation would require
disruptive substation works
– Known choice
• Rogowski Sensors
– Can be installed around
existing cable cores
– Accuracy considerations
• Innovations
– Sentec GRIDKEY current
transducer
– Now on the market
Measuring Voltage
• Terminal Block Connection
– Possible on modern fuse cabinets
(eg Lucy Trifca)
– Constrained cable routing
– Need to drill holes in enclosures?
• Direct Busbar connection
– Requires work on live busbars
– Connection leads need to be
routed away from operational area
• Innovations
– Drummond G clamp
– Now on the market
Data Aggregation
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Manufacturers offered integrated solutions
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Early versions had limited functionality
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Aerial extensions were required
Data Storage in the data aggregator
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They had difficulties with measurement of directional current and harmonics
Communications
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Current Group offered Open Grid product
GE offered a C650 Relay / RTU, designed to work with ENMAC
Selex Galileo offered their Sentec Gridkey product
Issues with capacity and reliability
Cabinets
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Issues with size, weight, IP rating and mounting
Equipment Connection
Current Group
Open Grid
Chalvey Local s/s
Harmonics
Real and
Reactive Power
Selex Galileo / Sentec - GridKey
Communications
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Modes of Operation
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Protocol - DNP3
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Streamed (Real Time measured data)
Half Hour (Calculated data)
Alarms (Un-solicited data)
For use with existing SCADA based control systems
Standardised template was needed
Storage
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Pi Historian
Further investigation
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Streamline installation process?
(Thames Valley Vision Project)
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Equipment life-cycle – what should we expect from
manufacturers?
(Thames Valley Vision Project)
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Total monitoring system accuracy?
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Monitoring systems’ own energy usage?
Key Learning Points
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Live retrofitting can be done
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Today’s equipment can monitor complex electrical
parameters
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LV network is as unbalanced as we thought!
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Monitoring is a system. Comms and data storage
are key features, not bolt on extras
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Manufacturers value access to DNO networks – help
them to help you
Thank you
Any questions?