Smart Urban Low Voltage Network

Low Carbon Network Fund Tier 1 Project

UK Power Networks & TE Connectivity

Improved safety

Enhanced network

modelling / planning

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

Quality of Supply

improvements

Active Network Management

LV Remote Control & Automation– System Component Devices

Installed to LV Link Boxes

Load-break / fault-make switches replace solid links in LV Link Boxes

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.

RTU (Remote Terminal Unit) provides remote control of the LV devices.

Single phase fault-break / fault-make circuit breakers (CB) retrofitted in place of the existing LV fuses.

At the distribution substation

LV CBs installed to a LV distribution board at a UKPN IFI trial site.

LV Remote Control & Automation - Smart LV Network Overview

Project Scope & Key Objectives:

Evaluate and demonstrate the benefits of the technology over a 24 month trial/demonstration phase.

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.

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.

Industrialisation & control integration Deployment

Use highly granular visibility of the LV network to improve our understanding and management of the LV network.

LCNF Tier 1 - Project Location

Area 1 – City Rd B South West Feeder Group.

Area 2 – City Rd B North West 1 & North West 4 feeders.

Trial will covers a total of 54 secondary substations supplying approximately 8400 customers.

LCNF Tier 1 - Project Location & Scale (Area 1)

7

Area 1 – SW Feeder Group Secondary Substations

•3 Feeder Group, with 38 distribution substations (27 to be populated).

•Area is experiencing loading issues (inc load related fuse operations).

•65 link boxes to be populated with LV remote control devices.

City Rd B South West feeder group; evaluate proactive management of the LV network.

LCNF Tier 1 - Project Location & Scale (Area 2)

8

Area 2 – NW 1 & 4 Feeders

•25 distribution substations, covering area of approx 2km Sq.

•Consistently worse feeders from CI/CML perspective.

City Rd B North West 1 & North West 4 feeders; evaluate benefits to network performance, offered by remote control and automated switching.

•101 link boxes to be populated with LV remote control devices.

LV Network Visibility – Load Monitoring

A

BC

D

NOP

-1 x RTU-3 x CBs

-1 x RTU-3 x CBs

-Fully populated 4 way LB, NOP in quadrant C

-3 quadrants populated (9 switches installed ) as one quadrant leads to pot-end

Results from an early IFI TrialSmart Urban LV Network –

Available Analogues

Measurement samples over 30 minute intervals.

Voltage: Min, Max, Average

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 %

Voltage harmonics: Max % harmonics up to 50th harmonic (available on demand from direct request to RTU)

LV Network

Faults

LV Network Visibility

Safety

• Response and isolation can take a number of hours

• Penalties incurred & high operational costs to resolve

Remote Control

• Reduce operating costs for fault response

• Faster restoration of supply to customers

• Improve reliability statistics

• Feeder overloading due to EV, heatpumps, etc.

• Voltage or harmonic issues due to renewable generation

Load monitoring

• Feeder and network voltages• Load current and direction• Peak fault current and direction• Enables integration of distributed

generation and EV

• Hazardous manual operations• Contact arcing• High fault currents• Damage to transformers &

cables

Solid state switching

• Arc-less current switching• Fault sensing technology• Intelligent load make/ fault make

technology• Phase-Phase voltage fault

verification / alarms

Key problems and solutionsTraditional LV Network Smart LV Network

Reliable communication to underground LB for control and load monitoringPower 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 withstandHigh 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 ForceFB = 4.45 x i2 x 10-7 (N)

Ref: Electrical Contacts (Paul G. Slade)

Compact switching technology

• Thyristors gate drives are switched on just prior to zero crossing

• Pulse peak current measured

• Progressively increase pulse duration

• Analyse peak currents• Determine if current is

due to load or a fault

Thyristor module

Solenoid actuator Mechanicaly

operated switch

Cur

rent

Vol

tage

Load Make

Fault threshold levelswitch will not close

Fault Make

Solid state switching technology

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.ukTechnical Development Engineer

Brendan Normoyle: bnormoyl@te.comTE Connectivity R&D Manager

Matthieu Michel : matthieu.michel@ukpowernetworks.co.ukTechnology Innovation & Co-ordination Manager