Who is Techimp? - MASC Association… · Online Non-Destructive Testing Monitoring Solutions of all...
Transcript of Who is Techimp? - MASC Association… · Online Non-Destructive Testing Monitoring Solutions of all...
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Condition Assessmentof Medium & High Voltage
Electric Assets
Who is Techimp ?
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A world-leading company in advanced testing and monitoringsolutions for electrical assets including:
• High Voltage and Medium Voltage Underground Cable Systems
• Power & Distribution Transformers
• GIS (Gas Insulated Switchgear)
• MV Switchgears
• Motors and Generators
We are experts in partial discharges (PD) and we design andbuild testing equipment, sensors and analysis software.
Infantmortality
Randomfailure
Standardaging
time
Ris
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ailu
rera
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Reduced risk with
CBM and quality
control
without diagnostic&standard aging
On-line/Off-line assessment
Short term monitoring
Risk Management
The information provided here is for informational and educational purposes and current as of the date of publication. The information is not a substitute for legal advice and does not necessarily reflect the opinion or policy position of the Municipal Association of South Carolina. Consult your attorney for advice concerning specific situations.
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Electric System
o Reliability of the electric system is of utmost importance.
o The majority of assets fail as a consequence of a problem in the insulation
system.
o Challenge: the electric infrastructure is ageing and many critical assets are
approaching end of life. Failure can have costly consequences.
o Partial Discharge testing helps our clients understand the health of the
insulation and therefore the health of their electrical assets.
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Techimp Services
Factory Acceptance Tests
Commissioning Tests
Offline Testing (VLF or RTS)
Online Non-Destructive Testing
Monitoring Solutions of all Assets
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Partial Discharge
Partial discharge (PD)
Localized electrical discharge that only partiallybridges the insulation between conductors andwhich can or can not occur adjacent to aconductor.
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PD normally develop in air gapsor on insulation surfaces, due todefects in the insulation system.
PD is correlated to insulationageing, insulation degradation.
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Why Test for PD?
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PD is related to local defects within the insulation system
PD is the fastest insulation degradation mode
PD can be triggered by overvoltages
Internal PD
Surface PD
Corona PD
HA
RM
FU
LN
ES
S
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Identification of the different typeof PD can be done by PD Pattern analysis
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MAIN INSULATION
JOINTAND TERMINATION
SURFACE PD
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Techimp Technology Advantages
HardwareAcquires PD in UWB modeFull spectral content of each PD pulse available, allowing
for more powerful analysis
Analysis SoftwareProprietary T-F Map SoftwareReadily separates external noise and disturbancesCan separate different types and sources of PDMinimizes false positives or false negatives
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Techimp advantages
Separation
IdentificationDiagnosis
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Advanced noise rejection and Pulse UWB analysis
T-F map technology for separation of PD phenomena
Same PD detector for all electrical apparatus
Techimp Technology – Online Test
Online Partial Discharge testAssessment is performed online at operating system
voltageNo outages or switching operations are required
Non-destructiveNo signals are impressed on subject cablesNo over-voltage is appliedWill not activate harmless PD sitesSwitching transients are avoidedDoes not shorten the remaining life of the cable
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Techimp Online PD Advantages
RapidOnline data acquisition is performed in minutesAbility to assess ~50% more segments compared to
Offline Testing. SafeSubject cables are not disconnected from the systemExposure of personnel to energized environments is
minimized. CompleteAssessment results indicate the condition of the insulation
of the asset and its accessories, and can identify problemswith connected equipment.
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Cable Applications
Any voltage class from 2.4 kV
All types of insulation; PILC, EPR, HMWPE, XLPE, TRXLPE and Butyl Rubber
All conductor sizes
Laminar, extruded, armored and/or mixed cable circuits
Any circuit configuration: straight or branched
All installations - direct buried, conduit, or trays
Conduit
Direct buried
Concreteencased conduit
Laminar, extruded &mixed cable circuits
Branched circuit
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Data Acquisition
Portable Equipment
50’ Test Leads
May acquire data from one or multiple phases
5-8 minutes to record data for each placement
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Sensors
Techimp Proprietary Sensors
Signal activity is detected with proprietarycapacitive or inductive sensors
Both types of sensors have high sensitivityon PD detection
U-Cap sensors are available with differentsize openings (1.5 to 6 inch)
U-Cap sensor is operated with hot stick-safety
Easy and fast for sensor placement
Techimp U-Cap sensor
Techimp HFCT Clamp sensor
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Coupling Capacitor:Installed in parallel to the transformer bushings.
MV Transformers
HFCT 140mm:Installed around the MV cable connected to the
transformer.
HFCT 39mm:Installed around the ground lead of the MV
cable termination.
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MV Transformers
U-Cap sensor:Installed on the cable close to theaccessory (terminations and joints).
FMC:Installed on the cable close to theaccessory (terminations and joints).
Cables
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Cables
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HFCT 39mm:Installed around the ground lead of thecables (terminations and joints).
HFCT 140mm:Installed around cables, where ground leads are notavailable. (terminations and joints)
Cables
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Sensor Placements
Sensor placements Each end below
termination Each splice location
(when accessible) Mid-span for excessively
long segments
RF source incable insulation
RF signal path RF signal path
Sensor placement at device #1.
Sensor placement at device #2.
Detectioninformationacquired atboth devices,one after theother.
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Cables
Conduction
HFCT
PD EVENT
HFCT
Ucap
Cables
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Data Analysis
Data analysis is performed in both frequency and time domains.
T-F Map is employed for noise rejection and PD signal separation.
The defects are identified using the phase resolved discharge pattern.
The success rate of the online assessment is proved by the NEETRAC CDFIreport.
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PD Signal Attenuation
Defect
Location
Pulse direction
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pC
MHz
PD Signal Attenuation
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pC
pC
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The phase of PD pulse with respect to thevoltage applied
Typical PD pattern Repetitionrate and amplitude of PD
signal
PRDP pattern TF map
Different cluster of PD; possible toseparate all differentPD and noise
corresponding its PRDP pattern
Complete analysis of multiple PD sources
PD DATA ANALYSIS: T-F MAP
Signal Separation with T-F Map
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Corresponding Sub-PRDP patterns:
By separating different cluster showing in TF map,specific PD pattern corresponding PRDP can bepresented, which can be used for further analysis.
Black phenomenonBackground Noise
Example of points clustering separation inthe T-F map
PD DATA ANALYSIS : T-F MAP EXPLOITATION
Red phenomenonInternal PD
Blue phenomenonSurface PD
Signal Separation with T-F Map
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Phase Resolved Pattern
Phase Resolved Discharge Pattern Analysis
Signal Intensity
Pulse Repetition
Phase Angle
Signature
Synchronicity
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• Amplitude
Corona Discharge
HV
• Repetition Rate • Phase Resolved Pattern
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Surface Tracking Discharge
• Amplitude • Repetition Rate
• Phase Resolved Pattern
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1
0.5
0
-0.5
-1
• Amplitude • Repetition Rate
Insulation Cavity Discharge
• Amplitude • Repetition Rate • Phase Resolved Pattern
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Cable & Splice Degradation
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Partialdischarge
FAILURE
Partialdischarge
Partialdischarge
Partialdischarge
Electrical trees: Produce measurable PD
Partialdischarge
Partialdischarge
ContaminationElectricalTreeing
Protrusionor Cavity
InterfacialDischarge
or Tracking
SurfaceTracking
ExternalDamage
PD Levels
Level 1-The system is not degraded.
No immediate action needs to be taken.
Level 2-There is a small amount of aging related signals.Re-Test is recommended within two years.
Level 3-Component has a low to moderate level of deterioration.System has low probability of failure within the next two years.Re-Test is recommended within one year.
Level 4-System has medium probability of failure within the next two years.Further discussion is required with the customer to determine the viabilityof repair or replacement.
Level 5-Component is at the end of economic life and hasa high probability of failure within one year.Recommend immediate attention.
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Probability of Failure
NEETRACNatl Electric Energy Testing, Research
& Applications Center
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Report-Table
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Report-Diagram
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Summary
Advantages of Online PD Testing
Ensure electrical system reliability
Avoid unplanned outages & power quality problems
No outages or switching operations are required
Prioritize or defer electrical system maintenance andreplacement
Assess entire cable system & assets, regardless ofinsulation or circuit configuration
Ability to assess 50% more segments per day
Verification of craftwork in newly installed assets
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Questions?
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Case Study #1 - Utility
Performed Condition Assessment inOctober
Manhole to manhole segment of 3-phase500kcmil AL 175mil XLPE
Terminated to bus work in manhole with600amp T-bodies
Analysis of RF signal data identified strongdischarges in T-body on Phase C
Phase C terminator was assigned Level 4with a Moderate to High probability offailure and replacement of the terminationwas recommended in the report
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The terminator remained in service
The terminator failed in March
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Case Study #1 - Utility
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