Introduction
1. Risk
Death / Injury
Unscheduled Downtime
Loss of Electrical Assets
Environmental impact
2. Focused on “Win Win”
3. PPE
4. Other preventative measures
Introduction
What are the Issues
Cause vs. Symptoms
A Proactive Approach
The Technologies
Understanding the Limitations
Examples
Case Studies
Electrical Faults
%
Insulation Failure 95 90 84 53 7
Mechanical Failure 5 0 4 36 23
Other Failure 0 10 12 11 70
<12 Months since last maintained 10 25 34 22 58
12-24 Months since last maintained 35 45 38 57 42
>24 Months since last maintained 55 10 22 19 0
No PM 0 20 5 2 0
Considering all failures on average 8% to 23% Age Related
77% to 92% Other reason
Switchgear
Bus Duct
Transformers
Motors
Generators
Source: IEEE Std. 493-1997 (Gold Book)
Corona
Partial Discharge
Ionisation of the air molecules at locations of
high stress
Produces corrosive gases Ozone and Nitrous
Oxides
Is influenced by humidity levels
Tracking
Flow of electricity over a Interface of dissimilar
materials, insulator/air, insulation/conductive
tapes.
Must have a path to aid in its development
Constant build up and release of energy
Arcing
Flow of electricity from one conductor to another
Results in the rapid destruction of all connected
equipment
Rapid expansion of Gas
Causes fires and explosions
Extremely violent
Generates extreme temperatures
A Proactive Approach
Understanding
Being Proactive
Surveys and Inspections
Taking precautionary measures
PPE
Explosion containment panels
Explosion vents
Training
Thermography (Infra-Red)
Indicates a “hot spot” in relation to those around
it.
Detects radiant energy
Line of sight
Surface measurement
Advantages
Easy to relate
Goes with our natural senses (seeing is
believing)
Comparable
Accurate
Exclusively used for poor connections
Training (Don’t believe everything you see)
Thermography (Infra-Red)
Ultrasound
Beyond the Range of Human Hearing
Generally any sound signal above 20kHz
Travel through Gases, Solids and Liquids
Travels in a very Directional Nature
Low Energy Signal
“Listen” to it
Measurable
Recordable
Scalable
Ultrasound
Advantages
Easy, quick and accurate
Can measure, record and analyse for severity
Scalable
Does not require “line of sight”
Great for closed, Live switchgear
Great for Bushings
Radio Frequency
Advantages
Detects fast transients
Detects the presence of all defects
Can be used in substations or on overhead lines
Fast “indication” technique
TEV (Transient Earth Voltages)
PD within MV/HV equipment induces a voltage
on the inner surface of switchgear cubicles and
panels.
Electrical measurement and analysis of radio
frequency cable insulation ageing signals which
are emitted from the cable whilst it is in normal
service.
Online Condition Assessment
The Signs and Signals
Partial Discharge
Smelly Gas (Ozone)
White powdery deposits
Generates Ultrasound
Generates Electromagnetic radiation
Radio Frequency
UV
TEV
Does NOT generate radiated heat
The Signs and Signals
Arcing
Generates Ultrasound
Does generate Heat
Generates Electromagnetic radiation
Radio Frequency
UV
TEV
Generates large quantities of UV
Detection Methods - Legend
Technology Corona Tracking Arcing
Infra-Red •
Ultrasound • • •
Radio Frequency • • •
TEV • •
UV • •
Cable Assessment • • •
Understanding the Limitations
Technology Limitations
Infra-Red Line of Sight, Advanced stage defects, Defects generating heat
Ultrasound Limited to accessible signals
Radio Frequency Multiple RF sources, diagnosis not possible
TEV Minimal diagnostic abilities, multiple sources
UV Line of sight
Cable Assessment Not portable, requires a specialist service provider
Presentation guidelines
Speakers should try not to exceed 24 slides per
25 minute presentation (Roughly one slide per 1
or 2 minutes of talk and 5 minutes for questions.)
Do not forget to bring a copy of your
presentation with you on the day!
Short phrases, not long sentences.
Presentation guidelines
Use Arial or similar font, try keep font at 28
points or larger and no smaller than 20 points so
people in the back of the conference room can
read your slides.
Titles should be 33 points or larger.
Do not use sound effects, they slow down
slide transitions and the noise from projection
computer may distract audience.
Presentation guidelines
Rather use video clips if sound and recordings
are required for your presentation. Please
discuss this with the organizers so that
arrangements can be made to accommodate
your request.
Presentation guidelines
Please do not number your slides
Each slide should have a title
9 lines max on a text slide
Maximum 10 words per line
Caution: Red, orange or yellow lettering and
lines become unreadable when projected.
Presentation guidelines
Watch out for:
Wingdings.
MS line draw.
Monotype sorts.
Scientific symbol fonts.
Asian language fonts.
Can embed TrueType fonts in file.
Presentation guidelines
Use of pictures, graphics, tables, etc. is at the
discretion of the speaker:
Keep diagrams simple and easy to view
Make text readable with large font
Use all space in rectangle
Make sure your presentation is readable when
printed in black and white
Presentation guidelines
Branded or company logos are only permitted on the opening slide.
Logos (other than that of the event logo) may not be used throughout the presentation, unless prior authorization has been obtained from the organizers.
Presentation guidelines
Deadline for submission of presentation for
the proceedings: 12 April 2013
Please ensure that you bring a copy of your
power-point slides with you on a memory stick
the day of your presentation. If you change your
slides please email the organizers asap with the
updated copy.
Presentation guidelines
For any additional information, please do not
hesitate to contact Nicolette Pombo-van Zyl:
Email: [email protected]
Phone: +27 21 700 3554
Mobile: +27 83 344 3198
Spintelligent (Pty) Ltd
Phone: +27 21 700 3500
Fax: +27 21 700 3501