Smart Urban Low Voltage Network
Low Carbon Network Fund Tier 1 Project
UK Power Networks & TE Connectivity
Project Background
•
Follow-on project after successful IFI trials.
•
IFI project aims: Develop a new solid-state switching technology for use on the LV
distribution network.
•
LV Remote control and automation system utilising retrofit switching devices to be
installed and trialled on LPN LV network.
•
Project registered in July 2012 – Project aims:
- Undertake a large scale demonstration of technology developed in the IFI project.
- Explore the benefits provided by an integrated LV remote control and automation system.
Maximise
utilisation of
plant
Active Network
Management
Quality of
Supply
improvements
Improved safety
Enhanced
network
modelling /
planning
LV Remote Control & Automation
– System Component Devices
At the distribution substation
RTU (Remote Terminal Unit)
provides remote control of the LV
devices.
Installed to LV Link Boxes
Load-break / fault-make
switches replace solid links in
LV Link Boxes
Single phase fault-break / faultmake circuit breakers (CB)
retrofitted in place of the
existing LV fuses.
LV CBs installed
to a LV distribution
board at a UKPN
IFI trial site.
Local control of
switches
provided by a
control panel (fits
under LB lid).
Switches being
installed to a link
box in place of
standard links.
LV Remote Control & Automation
- Smart LV Network Overview
Project Scope & Key Objectives:
Industrialisation & control integration
Industrialise existing technology supplied for a
small scale IFI project.
Integrate the LV remote control technology with our
existing control platforms (via DNP3, and PLC)
Implement active network management tools.
Deployment
Strategically populate 2 selected areas
within the LPN LV network with the LV
Remote Control & Automation devices
(54 secondary substation sites).
Actively manage the LV network to
improve network performance.
Use highly granular visibility of the LV
network to improve our understanding
and management of the LV network.
Evaluate and demonstrate the benefits of the technology over a 24 month
trial/demonstration phase.
LCNF Tier 1 - Project Location
Area 2 – City Rd B
North West 1 &
North West 4
feeders.
Area 1 – City Rd B
South West
Feeder Group.
Trial will covers a
total of 54 secondary
substations supplying
approximately 8400
customers.
LCNF Tier 1 - Project Location & Scale (Area 1)
Area 1 – SW Feeder Group Secondary Substations
City Rd B South West feeder group;
evaluate proactive management of the
LV network.
•65 link boxes to be populated with LV remote
control devices.
•3 Feeder Group, with 38 distribution
substations (27 to be populated).
•Area is experiencing loading issues (inc load
related fuse operations).
7
LCNF Tier 1 - Project Location & Scale (Area 2)
City Rd B North West 1 & North West 4 feeders; evaluate benefits to network
performance, offered by remote control and automated switching.
Area 2 – NW 1 & 4 Feeders
•101 link boxes to be populated with LV remote
control devices.
•25 distribution substations, covering area of
approx 2km Sq.
•Consistently worse feeders from CI/CML
perspective.
8
LV Network Visibility – Load Monitoring
Results from an early IFI Trial
Smart Urban LV Network –
Available Analogues
Measurement samples
over 30 minute intervals.
-1 x RTU
-3 x CBs
Voltage: Min, Max, Average
D
A
N
O
P
C
B
-Fully populated 4 way
LB, NOP in quadrant C
Current: Min, Max, Average
Real Power: Min, Max, Average
Reactive Power: Min, Max,
Average
Power factor: Min, Max (i.e.
closest/furthest from unity)
Average THD %
-3 quadrants populated (9
switches installed ) as
one quadrant leads to
pot-end
-1 x RTU
-3 x CBs
Voltage harmonics: Max %
harmonics up to 50th harmonic
(available on demand from
direct request to RTU)
Key problems and solutions
Smart LV Network
Traditional LV Network
LV
Network
Faults
LV
Network
Visibility
• Response and isolation can
take a number of hours
• Penalties incurred & high
operational costs to resolve
• Feeder overloading due to EV,
heatpumps, etc.
• Voltage or harmonic issues
due to renewable generation
Remote
Control
• Reduce operating costs for fault
response
• Faster restoration of supply to
customers
• Improve reliability statistics
• Feeder and network voltages
Load
monitoring
• Load current and direction
• Peak fault current and direction
• Enables integration of distributed
generation and EV
• Arc-less current switching
• Hazardous manual operations
• Contact arcing
Safety
• High fault currents
• Damage to transformers &
cables
• Fault sensing technology
Solid state
switching
• Intelligent load make/ fault make
technology
• Phase-Phase voltage fault
verification / alarms
Reliable communication to underground LB
for control and load monitoring
Power line carrier communications
• Power line carrier reliability and performance critical
especially during LV faults
–Existing solutions for smart metering inadequate for LV
network automation
–Design of end to end communication layers above plc
networking layer critical to success
• G3 plc offers improved bandwidth and network formation
–Higher bandwidth necessary for load monitoring
–Lab test benches to simulate LV network environment
–Validate performance during field trials
Short circuit withstand
High short circuit withstand requirements for densely
populated urban LV Network
• Silver tip contact welding or arcing due to
blow-off forces
– Load break switches utilise canted spring
contact system with novel method for
increasing contact force to reduce blow-off force
– Canted springs increase the number of
contact points and current paths
– n multiple contacts create n (i/n) current paths
and reduces forces by 1/n
Blow apart Force
FB = 4.45 x i2 x 10-7 (N)
Ref:
Electrical Contacts
(Paul G. Slade)
Compact switching technology
Solid state switching technology
• Thyristors gate drives are
switched on just prior to zero
crossing
• Pulse peak current measured
Solenoid
actuator
Mechanicaly
operated switch
Thyristor
module
• Progressively increase
pulse duration
Voltage
• Analyse peak currents
• Determine if current is
due to load or a fault
Current
Fault threshold level
switch will not close
Load Make
Fault Make
Usability Challenges & Solutions
• Retrofit solution
– Space constraints within link boxes
– Optimising design to work with wide variety of installed LV
switchgear
• Safety and operator issues
– Introduce safety features to prevent un-intentional operations
– Regular design review meeting using rapid prototypes to address
installation and safety issues
– Improvements to remote control functionality and usability based
on user feedback
• Load monitoring
– Optimisation of parameters monitored to match bandwidth
available
– Harmonic data storage and transfer separate from SCADA
system
Progress
•
•
•
•
Site selection and surveys complete.
Demonstration area preparation underway.
Next Gen PLC technology trialled and evaluated.
Tier 1 hardware industrialisation underway.
• Approach to control integration (dynamic LB movement
agreed)
First 14 site deployment planned for Jun 2013
Thank You
Any Questions?
Contact Details
Alexander Di Donato: alexander.didonato@ukpowernetworks.co.uk
Technical Development Engineer
Brendan Normoyle:
bnormoyl@te.com
TE Connectivity R&D Manager
Matthieu Michel :
matthieu.michel@ukpowernetworks.co.uk
Technology Innovation & Co-ordination Manager