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A Sustainable UK Electrical Energy Infrastructure. J.W. Spencer. Centre for Intelligent Monitoring Systems (CIMS) Dept of Electrical Engineering and Electronics. Scope of Research. Energy is a broad theme encompassing a wide range of activities, - PowerPoint PPT Presentation
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A Sustainable UK Electrical Energy Infrastructure
J.W. Spencer.
Centre for Intelligent Monitoring Systems (CIMS)
Dept of Electrical Engineering and Electronics
Scope of Research
Energy is a broad theme encompassing a wide range of activities,including enabling and supportive technologies (e.g. control, condition monitoring
etc)
CIMS research addresses issues to do with:
High Current phenomena.
• Mainly relating to the electrical network at Transmission and Distribution levels.
• Includes electric arc discharges, current interruption, alternatives to SF6.
• Electrical transients in gas insulated coaxial systems etc following current interruption (i.e. high rates of rise of voltages are induced).
• Electromagnetic control of high current discharges (up to 100kA).
Scope of Research
Monitoring of complex conditions.
• Including optical and non optical fibre sensors and systems.
• Use of a generic methodology for extracting latent information from data/sensor output.
• Condition monitoring.
• A method for dealing with complex systems.
• Cost effective monitoring.
EPSRC funded SUPERGEN V Programme(Tackling the sustainable energy infrastructure)
Part of a consortium of 6 universities (Edinburgh, Liverpool, Manchester, Queens Belfast, Strathclyde, Southampton) involved in a programme on Asset Management for Performance of Energy Systems (AMPerES).
Supported by the major transmission and distribution companies in the UK.
Liverpool is involved in 2 themes: Environmental and Monitoring. Environmental – exploring the possible removal of Sulphur
Hexafluoride from High Voltage plant. Monitoring – cost effective monitoring of distribution and
transmission substations and systems.
Example of High Current ResearchReplacement for SF6?
Priority theme (specifically mentioned in the Kyoto accord, National Grid, EPRI (US))
Research work in China. SF6 is a very good arc quenching medium due to its electronegative
properties. The chemical components at current interruption are in their
dissociated state. It is these components that aid arc extinction. Within micro-seconds the gas changes from a conductor to an
insulator as the dissociate gas recombines. Can particulates in a neutral gas (e.g. Nitrogen) provide the right
chemical components to aid arc extinction and dielectric withstand?
Computer simulation with expansion chamber
Finding the best arc quenching conditions e.g. gas flow, Finding the best arc quenching conditions e.g. gas flow, thermodynamic reactions, the right chemical species?thermodynamic reactions, the right chemical species?
Measured pressure rise for PTFE particles.
PTFE at arc column
1st row of flow passage 2nd row nozzle throat widening
Arc current waveform
No podwer
PTFE at expansion volume
-1
0
1
2
3
4
5
0 1 2 3 4 5 6 7 8 9 10
Contact gap length (cm)
Pre
ss
ure
(B
ar)
Measured pressure rise for PE particles.
PE at arc column
1st row of flow passage 2nd row nozzle throat widening
Arc current waveform
No podwer
PE at expansion volume
-1
0
1
2
3
4
5
0 1 2 3 4 5 6 7 8 9 10
Contact gap length (cm)
Pre
ss
ure
(B
ar)
Influence of polymeric particulates on arc voltage extinction peaks from the expansion chamber.
0
200
400
600
800
1000
1200
1 2 3 4
Arc Current (kA)
Ex
nti
cti
on
Pe
ak
(V
)
No powder in expansionchamber
PMMA powder in expansionchamber
PTFE powder in expansionchamber
PE powder in expansionchamber
2.5 4 6 9
Influence of polymeric particulates on arc voltage extinction peaks from injection.
0
100
200
300
400
500
600
700
1 2 3 4
Arc Current (kA)
Ex
nti
cti
on
Pe
ak
(V
)
No powder injected
PTFE powder injected
PMMA powder injected
PE powder injected
2.5 4 6 9
Cathode (moving contact)
Supports
PTFE ring
Power supply
cable
Anode(fixed
contact)
Interface tube
Insulated section
PTFE cylinder containing coil
HIGH SPEED PHOTOGRAPHS OF ARC CONVOLUTIONS
Arc in air, atmospheric pressure, quasi-dc 1.5kA (7500 frames per second)
136mm
22.5ms
A
C
21.6ms
A
C
130mm A
C21.6ms
Anode
Cathode
68mm 50mm
155mm
100mm
PTFE cylinder
A
C
112mm
18.9ms
A
C
A
C
118mm
19.8ms
A
C
20.7ms20.7ms
A
C
125mm A
20.7ms
Cathode (moving contact)
Supports
PTFE ring
Power supply
cable
Anode(fixed
contact)
Interface tube
Insulated section
PTFE cylinder containing coil
ARC MONITORING WITH THREE OPTICAL FIBRES
Fibre 1Anode
Cathode
PTFE cylinder
120 0
ArcFibre 2
Fibre 3
Locations of the three arc monitoring, optical fibres
Interrupter head
Arc rotation
Optical fibre sensors and monitoring systems
Convention was to use laser sources which are monochromatic with single mode optical fibres.
The chromatic approach uses wide band sources (e.g. white light) and multimode optical fibres.
A sensor modulates the white light and the chromaticity of the modulated signal returned to the detector is determined.
The chromatic approach provides a generic approach to optical fibre sensing and monitoring.
0
50
100
150
200
250
300
350
350 400 450 500 550 600 650 700 750
Wavelength (nm)
Ampl
itude
(a.u
.)
0
3000
6000
9000
12000
15000
18000
21000
P.S.
D. (
a.u.)
Integrate using three non-orthogonal Gaussian functions
Take a spectrum
Complex spectrum is reduced to
three RGB values
The RGB values are converted into
three chromatic numbers H (Hue),
L (Lightness) and S (Saturation)
Hue
Saturation
Lightness
White
Black
Hue
Saturation
Lightness
White
Black
(Dominant Wavelength)
(Spread or Bandwidth)
(Signal strength or Intensity)
How does Chromaticity differ from Colour?
Colour is a particular example of Chromaticity Chromaticity is extended outside the visible spectrum Responsivities of detectors and processors are variable Defines information in terms of a limited number of cross correlated
signals Chromatic methods may be deployed not only using wavelength but
also time, frequency, space, mass, acoustic etc domains Chromatic processing can extend to more than 3 spectral parameters,
generally up to 6. It is a highly flexible approach and uses readily available detectors
and sources but used in unconventional manners
BG
R
Freq.
Response
Amp.
Dominantfreq.
Bandwidth
Intensity
t1
t2
t3
Time
Chromatic process
Chromatic processing
Technology Transfer
Ongoing
Fuel quality (KTP) Detection of Bacterial Growth (KTP) Optical fibre based temperature sensors for HV transformer winding
monitoring (KTP)
Future possible
Oil monitoring (Joule Centre) Opto-acoustic monitoring system (required ~ 37 units required for 2
DNOs) (Manufacturer and end user supported University’s KT bid).
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