Distribution Network Visibility
Low Carbon Networks Fund Tier 1 project
UK Power Networks & PPA Energy
Omer Khan & Sarah Carter
 2012. UK Power Networks. All rights reserved
Project Background
• London Power Networks area (London) : All primary substations and more
than 9500 secondary substations equipped with Remote Terminal Units
(RTUs)
• Secondary substations RTU under-utilised
Voltage: 3 x phases
Current: 3 x phases
Total Power (kVA)
Power Factor
Real Power (kW) and direction
Reactive Power (kVAr)
Total Harmonic distortion
Air temperature
Total power in kVA
Power factor
1 x phase voltage
Air temperature
Disturbance recorder
Analogue limit excursion events
Harmonics 1-15th
• Opportunity: Maximise the utilisation of existing infrastructure
 2012. UK Power Networks. All rights reserved
Project objectives:
•
Fully utilise the capabilities of the primary and secondary RTUs. Collection of
additional analogues and new functionalities.
•
Develop and demonstrate a number of visualisation tools.
•
Demonstrate the business benefits. Asset Optimisation, Planning, Connections,
Network Operations, Control.
•
Evaluate optical sensors (PowerSense).
Project highlights:
•
Automated analysis of existing data from 9500 substations available.
•
RTU upgrade has started: 350 completed, to meet target of 600 by end 2012.
•
Beta version of Distribution Network Visualisation Tool being trialled.
•
Engagement with Business Units (Planning, Connections and Asset Management) to
refine tool and start to realise benefits.
 2012. UK Power Networks. All rights reserved
Analysis of Network data – Planning / Connections
Secondary substation utilisation:
•
Overview of load demand: Improve connections process.
•
Overview of load profiles: Identification of changes in load profiles with increase in LV
connected generation / heat pumps / electric vehicles.
•
Utilisation – mapping using colour pins
 2012. UK Power Networks. All rights reserved
•
Load profiling – variation during the day
Analysis of Network data – Planning / Connections
Secondary substation utilisation:
•
Utilisation – variation with time
with side by side comparison
using bar charts
•
 2012. UK Power Networks. All rights reserved
Utilisation – duration curve
Analysis of Network data – Planning / Connections
•
Load profiling – using colour pins on map
 2012. UK Power Networks. All rights reserved
Analysis of Network data – Asset Management
Secondary Substation Ventilation:
•
Overview of substation ventilation: Identify sites which may be inadequately
ventilated or which reach extreme levels of cold.
•
Potential to prolong transformer asset life.
•
Ambient air temperatures – colour pins on map
 2012. UK Power Networks. All rights reserved
Analysis of Network data – Asset Management
Primary Transformer Tap Changers:
•
•
Tap change operating time: Identify tap changer anomalies.
•
Tap change count: Inform maintenance frequency of tap changers.
Number of Tap Changer Operations in one day for each LPN Primary Transformer (Average 40)
 2012. UK Power Networks. All rights reserved
Analysis of Network data – Operations / Planning
Secondary Substation Voltage:
•
High / Low Voltage investigations – colour pins on map
••
Voltage
comparison
against of
limits
Inform decisions
in respect
voltage investigations.
•
Provide information in respect of effect of LV connected generation and voltage
 2012. UK Power Networks. All rights reserved
•
Voltage – Load relationship
Analysis of Network data – Planning
Secondary Substation 3Φ Voltage and Current Unbalance
•
Current Unbalance reports – Average and Maximum
•
•
Voltage Unbalance
•
Current Unbalance
Current unbalance – identification of worst case substations in respect of losses – consistent
unbalance – possible mitigation – cost / benefit
 2012. UK Power Networks. All rights reserved
Analysis of Network data – Planning
Secondary Substation 3Φ Voltage Total Harmonic Distortion
(THD)
Utilisation
•
Relationship with load / network configuration.
•
Helps with RTU alarm settings with a view to obtaining individual harmonic data over
defined levels/periods
 2012. UK Power Networks. All rights reserved
Generation Detection
•
Powersense monitoring trial:
 Connected at 11kV at water supply
works with generation
•
Secondary transformer load profile:
 Large PV (150kW) installation secondary
substation load vs solar radiation
Load on
secondary
transformer
Solar
radiation
PowerSense Optical Sensor
 2012. UK Power Networks. All rights reserved
Data Cleansing
•
Data quality affects analysis e.g. long term maximum/average/minimum figures.
•
Data cleansing algorithms developed to detect and remove anomalies where possible.
Spikes
Missing data
+/- spikes
Dropping out
Data anomaliesNon
zero
Spike
gap
 2012. UK Power Networks. All rights reserved
Gap
Scale fa
change
Measurement observations
•
•
Half Hour averaging of power factor – variation between leading and lagging – half
hour average incorrect.
Current Transformer (CT) location on one of two parallel cables between secondary
transformer and LV board. RTU doubles reading – apparent unbalance if cables not
sharing current
Transformer
Dual LV
Cable/Tail
Current
Transformer
Voltage Fuse
 2012. UK Power Networks. All rights reserved
Next Steps
•
•
•
•
Further engagement with business units;
Additional development in respect of usability required;
Investigations of additional RTU functionality in respect of alarms and event recording
continuing;
Integrated phase to start shortly,
– interfaces with existing databases and applications e.g Asset Data, Geographical
Network Data.
– additional functionality to be added to application.
 2012. UK Power Networks. All rights reserved
Thank You – Any Questions?
 2012. UK Power Networks. All rights reserved