2012. UK Power Networks. All rights reserved Distribution Network Visibility Low Carbon Networks Fund Tier 1 project UK Power Networks & PPA Energy Omer

2012. UK Power Networks. All rights reserved

Distribution Network VisibilityLow Carbon Networks Fund Tier 1 project

UK Power Networks & PPA Energy

Omer Khan & Sarah Carter

http://www.ppaenergy.co.uk/

http://www.powersense.dk/index.html


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

• Opportunity: Maximise the utilisation of existing infrastructure

Voltage: 3 x phasesCurrent: 3 x phasesTotal Power (kVA)Power FactorReal Power (kW) and directionReactive Power (kVAr)Total Harmonic distortionAir temperature

Disturbance recorderAnalogue limit excursion eventsHarmonics 1-15th

Total power in kVAPower factor1 x phase voltageAir temperature

Saved Functions not usedAvailable


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.


Analysis of Network data – Planning / Connections

• 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

• Load profiling – variation during the day

Secondary substation utilisation:



Secondary substation utilisation:

• Utilisation – variation with time

with side by side comparison

using bar charts

• Utilisation – duration curve



• Load profiling – using colour pins on map


Analysis of Network data – Asset Management

Secondary Substation Ventilation:

• Ambient air temperatures – colour pins on map

• Overview of substation ventilation: Identify sites which may be inadequately

ventilated or which reach extreme levels of cold.

• Potential to prolong transformer asset life.


Primary Transformer Tap Changers:

Analysis of Network data – Asset Management

• Number of Tap Changer Operations in one day for each LPN Primary Transformer (Average 40)

• Tap change operating time: Identify tap changer anomalies.

• Tap change count: Inform maintenance frequency of tap changers.


Analysis of Network data – Operations / Planning

Secondary Substation Voltage:

• Voltage – Load relationship

• High / Low Voltage investigations – colour pins on map

• Voltage comparison against limits• Inform decisions in respect of voltage investigations.

• Provide information in respect of effect of LV connected generation and voltage


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


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


Generation Detection

Solar radiation

Load on secondary transformer

• 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

PowerSense Optical Sensor


Data Cleansing

SpikeScale factor changeGapNon

zero gap

+/- spikes

Dropping out

Reduction/-ve power

Data anomalies

Spikes Missing data

• Data quality affects analysis e.g. long term maximum/average/minimum figures.

• Data cleansing algorithms developed to detect and remove anomalies where possible.


• 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

Measurement observations

Current Transformer

Voltage Fuse

Transformer Dual LV Cable/Tail


• 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.

Next Steps


Thank You – Any Questions?

Documents

2012. UK Power Networks. All rights reserved Distribution Network Visibility Low Carbon Networks Fund Tier 1 project UK Power Networks & PPA Energy Omer