Voltage Management of Low voltage (LV) BusbarsPlenary session B – Low voltage operation

Dan RandlesQuality of Supply and Technical Manager/LCNF Tier 1 Manager

LCNF ConferenceOctober 2012

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Aims and Objectives

Aim is to trial solutions with potential to help voltage management on LV networks and to provide operators with understanding of the potential for alternative methods to cope with the changing nature of demands• ability to effectively manage voltages in real-time in a safe and

economical manner will be assessed• effectiveness of devices to correct power factor will be assessed• Issues including phase imbalance and power quality to be

assessed where appropriate supported by simulations

30 month project started in April 2011 costing £0.5M

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Scope

6 sites selected for trials (11kV or 6.6kV)Simulations used to explore numerous scenariosPV clusters or high load areas (or both)LV network monitoring deployed (Incl. PQAs)

Dunton Green Edge Green Greenside

Howard St Landgate Leicester

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Network Monitoring (LVNS)

Scope of the deployment• 200 x 11kV or 6.6kV to 415V

distribution substations• Over 1000 LV feeders• Sites comprise indoor and

outdoor, mostly ground mounted with small number of pole mounted transformers

Analogues to be captured• RMS voltages and currents• Real and reactive power• 3ø + neutral • Temperature (Ambient, Tx)• Real-time (1 minute

averages!)• Harmonics (not real time)

Metrology and Communications

(V, I, Q, P, H, Temp)

GPRS/3GPrivate APN

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Trials

Three techniques were explored through field trialsNumerous more will be looked at through simulationsField trials:• Substation (ie busbar) voltage regulation via OLTC

distribution transformer• Harmonic filtering, power factor correction and phase

balancing via active filter • In-line (ie LV feeder) voltage regulation via power

optimizerField trials commenced in August 2012 and will continue for a period of 12 monthsToo early in the trial stage to assess results but lots of valuable practical learning already obtained

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Voltage Management – Active Harmonic Filters

As well as harmonic filtering the AHF provides load balancing and power factor correctionTechnical details:

• Active Filter Type PQFS – M10 amp• Voltage (V): 420V• Frequency (Hz): 50• Total Current (A): 100• Total Power (kVA): 71• IP Rating - IP30• Ambient Temperature -10oC/+40oC• Dimensions: W585 x D310 x H685

mmENW have installed the AHF at two locations in Manchester; 1 indoor and 1 outdoorFull harmonic studies have been completed prior to the installation to ascertain background harmonic levels

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Voltage Management – Power Perfector (PP+)

320kVA ratingVoltage optimiser has the capability to adjust target voltsAVC available taps (+4%, 0%, -4%, -8%, -12%) and (+2.7%, 0%, -2.7%, -5.4%, -8.1%)Operating temperature range: - 10oC/+50oCInstalled by-pass arrangement for trial

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Voltage Management – On load Tap changing Distribution Transformer

x2 OLTC distribution transformers from Reinhausen of Germany (MR)Technical details for the OLTC:

• 500kVA rating• x1 unit at 11kV and x1 unit at 6.6kV• Tapping range - 8% to + 8% in 8

steps of 2%• Utilises the MR OLITAP mechanical

tap changer• Tap changer incorporated within a

‘modified’ UK standard EFACEC Tx• Voltage control relay via

TAPCON230 with DNP3Delivered in September 2012 installation scheduled for DecemberFundamentals providing design and installation support for the AVC equipment

AVC

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LV Feeder Voltage Control

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Lessons learnt

Approvals, policies and authorisationsCustomer impact must be minimised particularly noise and interruptionsTrue partnering approach with all project stakeholdersAcademic support crucial to help make sense of resultsSite surveys essential to avoid problems during installationInstallation quality including anti tamper/vandalNetwork monitoring key to understanding the outcomesLarge volumes of data being generated which needs managing – requires new tools/systems

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Network Modelling

Topology Information MPAN

InformationConductorInformation

Relationship MPAN-Profile

Class

Profiles Class (half hourly

profile)

ReconnectionModel

OpenDSS Representation

Power Flow Simulation

From GISFrom other Database

Automatic Process

Validate

Extract

Analyse

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Future solutions

The adoption at scale of low carbon technologies will have a significant impact on LV networks• Voltage rise/drop

• Congestion/overload of assets

Monitoring is key to firstly understanding the capabilities of LV networks both now and in the future and secondly facilitating smart operation

Appears likely that active means of controlling voltages and loadings in LV networks will be implemented in the future

Significant change in operation and planning procedures for network operators

These techniques are introducing complexity into networks which are inherently simple – this represents a challenge to operators

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Thank you

Any questions…?