The Economics of Continuous Transformer Health ... - PQSynergy

pribblingchoppedElectronics - Devices

Nov 15, 2013 (3 years and 10 months ago)

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Terry Chandler

Power Quality Thailand LTD

PQsynergy 2011

Chiang Mai, Thailand

Sept 2011

WWW.powerquality.co.th

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Monitoring Technologies

Motors

Generators

Switchgear

Cables

Transformers

Motors

Generators

Switchgear

Cables

Transformers

Electrical Power Grid

3

Transformers and Bushings

Data
-
Information
-
Knowledge

Knowledge

Using the
information

Information
(Trend graphs etc)

Data (values of parameters)

Sept 2011

WWW.powerquality.co.th

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Basic System Capabilities (Data)


Transformer Monitoring, Control & Communications


Monitor Inputs:


Analogue (temperatures, fan motor current, DGA, PD)


Digital (switch positions, sensor outputs)


IED’s (Intelligent External Devices) Digital data


Provide Outputs:


Analogue


Digital Data


Communications


Visual


Monitoring and control of
transformers


Control
Functions if needed



Cooling Control


Voltage
Control including paralleling

Sept 2011

WWW.powerquality.co.th

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Transmission Transformer

FIBRE Optic TEMPERATURE SENSING



Direct
monitoring of temperatures occurring in winding
hotspots, core and other locations where
fibre

optic
probes
are
built in to transformer


Sept 2011

WWW.powerquality.co.th

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Bushing Health Monitor (BHM)

Alarms on:


Magnitude of the imbalance current


Trend of the imbalance
currents


Temperature
dependencies


Can be used for PD



Installation Core Ground Current RFCT

Installation CT

Bushing sensor and Flexible CT

Sept 2011

WWW.powerquality.co.th

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BUSHING HEALTH MONITOR


Continuous on line monitoring of bushings

real time
information
of bushing
capacitance and power
factor.



early
detection of possible failure
..

Sept 2011

WWW.powerquality.co.th

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On
-
line Tap Changer
(OLTC)
Monitoring


OLTC
Counter


OLTC Contact
Wear


OLTC
Hunting


Reversing Switch
Exercise


OLTC Motor Current
Monitoring


Auto Cleaning of the Reversing
Switch


OLTC Delta T Monitoring

Sept 2011

WWW.powerquality.co.th

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ELECTRICAL PARTIAL DISCHARGE


PD activity occurring in a transformer can be detected
by
monitoring from
the bushing tap (which is
commonly used in
factory
testing
).


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OEM sensor monitor functions


Auto
-
Recharging
Breather


OLTC Oil Filtration
System


OLTC Contact
Wear Sensor


Inert Air or N2
Generation System


Fan current (verify fans running)


Contact closures


Other

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Typical Monitoring system

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To
Scada

if available

Information real time


Sept 2011

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Reliability Improvement


With
on
-
line condition based data
,


condition
based alarms
when problems originate



early detection and action or intervention
promptly


Prevent unscheduled outages.


The analytical software
within the monitoring system


automatically
identify issues requiring maintenance attention.


The
recording of cooling system run
times


OLTC
operations


Sept 2011

WWW.powerquality.co.th

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Realizing True Capacity of
Transformer



Real
-
Time measurement of operational parameters
allows the

user
of the transformer to realize the true
capacity based on existing conditions of weather, load
etc.


optimal performance can be realized


Sept 2011

WWW.powerquality.co.th

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Maintenance Savings for
Transformers


The advanced analytics within the monitoring system
filters through the condition data to automatically
identify issues requiring maintenance attention.



The recording of cooling system run times and


OLTC operations provide useful data on the moving
parts components.


This provides Operations and Maintenance personnel
the appropriate information to schedule condition
based maintenance using information provided
directly by the asset.


Sept 2011

WWW.powerquality.co.th

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Information


Case Studies

Sept 2011

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Case Study 1 6.6 kV Motor



Motor with continuous PD monitor


This motor drives a large critical compressor
for a international customer.


This client has been using a continuous
partial discharge monitor for several years.
Recently there was a fast increase in PD
levels from the one of the RTDs.


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Increase in Partial Discharge


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Increase in PD activity


it was recommended that the motor be taken out
of service for inspection. An outage was scheduled
for May 2009.


Once the motor was placed back into service, all PD
levels dropped down to acceptable levels and have
remained at those levels.

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The defect was easily discovered
and field repairs were made.



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By proving this early warning, one can schedule a
planned outage. Taking a planned outage, is far more
cost effective than having an unexpected

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Economic return (knowledge)


Prevented catastrophic failure



By proving this early warning, one can
schedule a planned outage. Taking a
planned outage, is far more cost effective
than having an unexpected





Estimated Cost Savings: $91,000


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Economic returns


Reliability improvement


Realizing true capacity of transformer


Maintenance savings


Documenting life of transformer


Extend life of transformers




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Case 2
230 kV Bushing Data


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Scheduled
maintainance

Cost saving (Knowledge)




Estimated Cost Savings: Several
Million Dollars due to cost of a new
transformer and lost production.


Scheduled shut down and
replacement of Bushing
vs

unexpected failure and damage.

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Summary


Large transformer assets monitoring system provides
near real time data, alarming and historical data on all
transformer parameters.


Eliminates the need for manual measurements.


Alert the owner to do preventative repairs before a
major failure.


Lower the cost of transformer inspections and regular
servicing.

Sept 2011

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Thank You


Contact for more information


Terry Chandler Terryc@powerquality.org

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