Transcript PowerPoint File
LV Network Monitoring Demonstrating the Possibilities
25 October 2012 Gideon Evans
Introduction
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SSE’s Low Carbon homes
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Can LV Network Monitoring equipment be retrofitted without taking customers off supply?
Understanding the LV Network
• •
Capacity
– Current – MDI Information – Demand and Generation – more informed decisions
Performance
– Voltage Limits – Power Factor – Power Quality / Harmonics – more informed decisions Capacity Average Demand Demand XX:00 Time XX:30
Monitoring Equipment Measuring Voltage MDIs Rezap Fault management Measuring Current Calculated data Storage of data Transmission of data Installing Equipment
Measuring Current
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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
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Terminal Block Connection
– Possible on modern fuse cabinets (eg Lucy Trifca) – Constrained cable routing – Need to drill holes in enclosures?
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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
• • • • •
Manufacturers offered integrated solutions
– Current Group offered Open Grid product – – GE offered a C650 Relay / RTU, designed to work with ENMAC Selex Galileo offered their Sentec Gridkey product
Early versions had limited functionality
– They had difficulties with measurement of directional current and harmonics
Communications
– Aerial extensions were required
Data Storage in the data aggregator
– Issues with capacity and reliability
Cabinets
– 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
– Streamed (Real Time measured data) – Half Hour (Calculated data) – Alarms (Un-solicited data) •
Protocol - DNP3
– For use with existing SCADA based control systems – Standardised template was needed •
Storage
– 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 Today’s equipment can monitor complex electrical parameters LV network is as unbalanced as we thought!
Monitoring is a system. Comms and data storage are key features, not bolt on extras Manufacturers value access to DNO networks – help them to help you