Voltage Management of Low voltage
(LV) Busbars
Plenary session B – Low voltage operation
Dan Randles
Quality of Supply and Technical Manager/LCNF Tier 1 Manager
LCNF Conference
October 2012
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
Dunton Green
Howard St
Edge Green
Greenside
Landgate
Leicester
6 sites selected for trials (11kV or 6.6kV)
Simulations used to explore numerous scenarios
PV clusters or high load areas (or both)
LV network monitoring deployed (Incl. PQAs)
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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
GPRS/3G
Private APN
Metrology and
Communications
(V, I, Q, P, H,
Temp)
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)
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Trials
Three techniques were explored through field trials
Numerous more will be looked at through simulations
Field 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
optimizer
Field trials commenced in August 2012 and will continue
for a period of 12 months
Too 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 correction
Technical 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
mm
ENW have installed the AHF at two
locations in Manchester; 1 indoor and 1
outdoor
Full harmonic studies have been
completed prior to the installation to
ascertain background harmonic levels
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Voltage Management – Power Perfector (PP+)
320kVA rating
Voltage optimiser has the
capability to adjust target volts
AVC available taps (+4%, 0%, 4%, -8%, -12%) and (+2.7%, 0%,
-2.7%, -5.4%, -8.1%)
Operating temperature range: 10oC/+50oC
Installed by-pass arrangement for
trial
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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 DNP3
Delivered in September 2012 installation
scheduled for December
Fundamentals providing design and
installation support for the AVC
equipment
AVC
Voltage Management – On load Tap changing
Distribution Transformer
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LV Feeder Voltage Control
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Lessons learnt
Approvals, policies and authorisations
Customer impact must be minimised particularly noise
and interruptions
True partnering approach with all project stakeholders
Academic support crucial to help make sense of results
Site surveys essential to avoid problems during
installation
Installation quality including anti tamper/vandal
Network monitoring key to understanding the outcomes
Large volumes of data being generated which needs
managing – requires new tools/systems
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Network Modelling
Extract
Conductor
Information
Topology
Information
MPAN
Information
Reconnection
Model
Relationship
MPAN-Profile
Class
OpenDSS
Representation
Profiles Class
(half hourly
profile)
From GIS
Automatic Process
Validate
Power Flow
Simulation
From other
Database
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…?
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