PV impacts on Suburban Networks

Philip Bale

Western Power DistributionInnovation and Low Carbon Networks Engineer

01332 827448/07525241432pbale@westernpower.co.uk

LCNF Annual Conference - CardiffThursday 25th October 2012Understanding Networks – an early presentation of data

PV impacts on Suburban Networks

Connection of Photo Voltaic PanelsThe Feed in Tariff resulted in a dramatic increase in the number of distribution network connected Solar PV panels.

G83 connectionsThis was particularly prevalent in particular suburban networks, expedited by Local Authorities installing generation on their housing stock

Concern over the connection of PV generation to the LV network.The LV network has historically operated with very limited network monitoring and operates based on well known diversified load profiles. Significant amounts of PV in one area resulted in a increased number of assumptions being made.

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Monitoring in Nottingham• Aspley and Broxtowe – EDMI MK6E meters • Meadows – EMDI MK6E meters and portable

sub.net monitors

Analysis - Does a high concentration of Solar PV have an impact on:

• Network Voltage tolerances• Thermal Limits• Voltage Fluctuations and Flicker• Voltage and Current imbalance• Voltage and Current harmonics• Power Factor

Network Monitoring

23:59:59 1:30:00 3:00:00 4:30:00 6:00:00 7:30:00 9:00:00 10:30:0012:00:0013:30:0015:00:0016:30:0018:00:0019:30:0021:00:0022:30:00240

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LV & 11kV voltage – 24 hours

Network Voltage tolerancesBlue – LV busbar voltage Frinton Road Aspley,

Red – 11kV Tx1 & Tx2 voltage Cinderhill Primary substation

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Thermal Limits & Current Imbalance

4.295138888888870

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LV Current imbalance - July / August

Tunstall Crescent - Three Phase current over a two week period

Average current during the two week period• L1 – 68.96A • L2 – 99.12A• L3 – 125.89A

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Voltage and Current harmonicsVoltage and current waveformsThe effect of current harmonics on the waveform

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FrintonRoad

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Hilcot Drive

Lindbridge Road

Voltage Total Harmonic Distortion Total Harmonic Voltage distortions – one week period of sites in Aspley and Broxtowe8th - 14th October 2012

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Estimated original current

Solar radiation

Contribution of Solar PV for demandMeasured current - BlueSolar radiation - RedEstimated demand being masked by generation - Green

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PV’s in Suburbia

Early Learning

1. Voltage profile at the substation

2. Current imbalance of network feeders

3. Current and Voltage Harmonics – including waveforms

4. Voltage harmonics – Total Harmonic Distortion

5. Contribution from Solar PV to demand