Moving From Time Based Maintenance to Condition Based Maintenance (Webinar)

7/26/2019 Moving From Time Based Maintenance to Condition Based Maintenance (Webinar)

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Moving from Time Based Maintenance to

Condition Based Maintenance

Presented By: Thomas Linn Qualitrol LLCSeptember, 2013

Thomas Linn has a strong background of 20 years plus experience in high voltage equipmentsuch as gas insulated switchgear, high voltage bushings, cables, transformers, high voltagetesting, partial discharge measurement and monitoring and high voltage test equipment.

Thomas graduated from Technical University of Dresden with a degree in ElectricalEngineering, specialized in High Voltage Techniques. Afterwards he worked till today withhigh voltage equipment. 1998 he joint ABB in Switzerland and was responsible for HighVoltage Onsite Testing for GIS and cables, PD measurements onsite and PD monitoring ofGas Insulated Switchgear. 2003 he took over the responsibility for the High Voltage Test Labsfor routine and type testing mainly for high voltage transformer bushings.


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Agenda

Overview

1. Definitions around Maintenance

2. Traditional Methods and current state of Maintenance

3. Condition- based Maintenance (CBM) Basics

4. Challenges of Condition Monitoring Based Systems

5. Q & A


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Definitions around Maintenance


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Definitions around Maintenance

What is Maintenance?

Maintenance are actions necessary for retaining or restoring a piece of equipment,machine, or system to the specified operable condition to achieve its maximumuseful life.

Source: http://www.businessdictionary.com/definition/maintenance.html#ixzz2VFFiFfwd

Type of Maintenance?

Reactive maintenance (Run-to-failure maintenance)

Preventive maintenance (Time-based maintenance)

Predictive maintenance (Condition-based maintenance)

Source: http://performancealliance.org/Portals/4/Documents/Committees/NonResQM/OM_5.pdf


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Type of Maintenance Run-to-Failure Maintenance

Advantages

Low cost.

Less staff.

Disadvantages

Increased cost due to unplanned downtime of equipment.

Increased labor cost, especially if overtime is needed.

Cost involved with repair or replacement of equipment.

Possible secondary equipment or process damage from equipment failure.

Inefficient use of staff resources.

Definition:

Run-to-Failure maintenance (also known as corrective maintenance) involves all unscheduledactions performed as a result of system or product failure. Basically, it is an attempt to restorethe system/product to a specified condition.

Source: http://www.referenceforbusiness.com/management/Log-Mar/Maintenance.html#ixzz2VFbobDte



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Type of Maintenance Time- based Maintenance

Advantages

Cost effective in many capital-intensive processes.

Flexibility allows for the adjustment of maintenance periodicity.

Increased component life cycle.

Energy savings and Reduced equipment or process failure.

Estimated 12% to 18% cost savings over reactive maintenance program.

Disadvantages

Catastrophic failures still likely to occur.

Labor intensive. Includes performance of unneeded maintenance.

Potential for incidental damage to components in conducting unneeded maintenance.

Definition:

Time-based maintenance utilizes a previously developed maintenance schedule for eachasset/ equipment. This is much like an oil change on an automobile that takes place everythree months or 3,000 miles, whichever comes first.

Source: http://www.referenceforbusiness.com/management/Log-Mar/Maintenance.html#ixzz2VFbobDte



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Type of Maintenance Condition-based Maintenance

Advantages

Increased component operational life/availability.

Allows for preemptive corrective actions.

Decrease in equipment or process downtime.

Decrease in costs for parts and labor.

Better product quality.

Improved worker and environmental safety.

Improved worker morale.

Energy savings.

Estimated 8% to 12% cost savings over time-based maintenance program.

Disadvantages Increased investment in diagnostic equipment.

Increased investment in staff training.

Savings potential not readily seen by management.

Definition:

Condition-based maintenance involves all actions performed as a result of system or productcondition, detected by means of condition monitoring. Basically, it is eliminating causalstressors, with can lead to a degradation of the asset or equipment.



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Traditional Methods and current state

of Maintenance


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Traditional Methods and current state of Maintenance

A referenced study from US breaks down the average maintenance program asfollows:

>55% Reactive

31% Preventive

12% Predictive

2% Other

Note that more than 55% of maintenance resources and activities of an averagefacility are still reactive.

(Source: http://performancealliance.org/Portals/4/Documents/Committees/NonResQM/OM_5.pdf)


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Commonly accepted practice is to follow Manufacturers advised schedule, likechanging your cars engine oil at every 3000 miles or three months

1) A Utility company cannot keep up with time based maintenance in a deregulated

business model, and highly regulated environment protection.

2) Experience and proven studies demonstrate greater asset risk and dependingrevenue loss when using time based maintenance

Traditional methods lack the needed sensors and associated measurements toanalyze, record and suggest preventive maintenance or control actions

Assets like Battery banks, cap banks, underground cables are relatively difficultand expensive to maintain, often underserved by Utilities

Diagnostics, Reporting and control measures are mostly a manual processprone to errors. Requires constant training and retaining large crews.


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Full cost view includes secondary (invisible) costs:

Moral of employ Safety aspects

Reduced costs for parts and labor Secondary outage costs (penalties, branddamages etc.)

Inventory costs Indirect cost reduction due to longer lifetime

Full cost view includes secondary (invisible) costs:

Moral of employ Safety aspects

Reduced costs for parts and labor Secondary outage costs (penalties, branddamages etc.)

Inventory costs Indirect cost reduction due to longer lifetime

Traditional view includes primary (visible) costs:

Replacement parts costs Labor costs

Primary Costs for outages Storage costs

Traditional view includes primary (visible) costs:

Replacement parts costs Labor costs

Primary Costs for outages Storage costs

Cost calculation


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umberoftrouble

0~3 4~6 7~9 10~12 13~15 16~18 19~21 22~24 25~

Service years

OthersMaintenance DefectsEquipment Defects

In older Equipment maintenance is a big contr ibutor to failure!

(Source: CIGRE 1992)


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Condition- based Maintenance (CBM)

Basics


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Condition- based Maintenance (CBM) Basics

Condition-based maintenance is a set of activities that detect changes in the physicalcondition of equipment (signs of failure) in order to carry out the appropriate maintenancework for maximizing the service life of equipment without increasing the risk of failure.

Condition-based maintenance

depends on continuous or periodic condition monitoring equipment to detect the signs offailure.

Defining maintenance decisions

Assessing Condit ion of equipment

Intelligent data analyzing/ processing

Collecting the data

Defining valuable data to measure

Condition-based Maintenance


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What is needed to do Condition-based Maintenance?


Commitment of Management

Suitable Sensors

CBM Concept

Reliable System Knowledge

Data processing

CBM relevant quality data analyses by expertsystems

Maintenance decision based on data and Knowledge (automatic/ manuallysupported)


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CBM Concept

For a suitable CBM Concept the level o actions needs to be defined and represented in themonitoring system (different level of access etc.). The responsibilities, the included actionsand the expected decisions for each level needs to be clearly defined.

First Level: qualified data/ warning/ alarms will be provided (System)

Second Level: Information will be received, reviewed and acknowledged; decision about furtheractions will be drawn (e.g. by operator with system support)

Third Level: Received data will be further analyzed; decision about further investigation will be

drawn (e.g. by maintenance crew with system support)

Forth Level: Further investigations on the equipment itself (e.g. time- of- flight, oil sampling);decision about necessary maintenance actions will be drawn (e.g. external or internalspecialist with system support and/or additional diagnostic methods)

Fifth Level: applying maintenance (e.g. repair or replacement by external or internal stuff); the

decision about clearance for further operation will be drawn (e.g. maintenancemanager).

The above mentioned concept shows an basic example and might varies according to CBM strategy of theequipment owner, level of experience, level of competences etc.


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Suitable Sensors

The used sensors should be able to collect the measured parameter with a minimumdemanded sensitivity, which should be proven by means of state of the art methods anddocumented.

The sensors should not incorporate unnecessary risk to the monitored equipment, to OHSand environment.

Fixing and connection to equipment and the buildup of the sensor itself and all connectedparts should be resistant to the same environment as the monitored equipment itself at least.

The expected lifetime should be as long as the monitored equipment itself or, if not possible,

at the high end of state of the art of same kind of sensors.In case of a defect of a sensor, it should not result in a fault of the monitored equipment.


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Reliable Monitoring System

The connected monitoring system should provide different level of access according to thelevels in the CBM concept (e.g. red and green light for first level, some data analysesfeatures for the second level etc.).

It should be suitable to withstand the environment where it will be installed.All system failures should create a signalization to first level.

The system should be meant for long life operation, equipped with proven reliablecomponents/ parts.

The user interface needs to be so designed, that it is easy to use and all information provided

must be easy to find according to the level of access.The recorded data have to be stored in a save and reliable way.

The system should be able to be integrated to station networks, equipment owner privatenetworks and phone lines.


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Scalable System Architecture:

1) Scalable from single asset to a complete substation, or to include complete Utilityinfrastructure

2) Choice of integration in existing SCADA or an independent CMBS3) Optional use of Cloud computing, web interface, apps for smart phones

Mature information management and rule packs for data interpretations

1) Minimize nuisance alarms

2) Accurate interpretation with specific recommendation for maintenance action3) Custom reporting capabilities for different levels of organization

4) Long term archival (1 to 10 years), trending and projected asset availability


Reliable Monitoring System further properties


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Integrated solution - Example of data integration


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Integrated solution - Example SmartSUB

SF6 monitor DGA monitor (8 gases)

PD moni tor


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Data processing and CBM relevant quality data analyses by expert systems

Condition monitoring is a joint effort between

manufacturers (OEM and 3rd parties, utilities

(equipment, P&C, communications) and software

developers

The data analyses system should be a

development with Utilities, OEMs and University

researchers to provide best in class modelling and

simulation module accuracy to ultimately provideautomated link to CBM planning tools.

The messages to the user should be clear and

should provide the necessary information to

assess the cause of the degradation of physicalcondition (e.g. type of defect, area of source etc.)

Raw DataFrom Sensors

Signal Processing

Qualify DataBased on CM Attributes

Boolean / Fuzzy LogicBased Expert System

Artificial Neural Network

Expert Systems (Diagnostics & Modelling)

AutomatedCBM Planning


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Example: Transformer Dissolved Gas Analysis Diagnostic

First new DGA diagnostic tool in decades

Correct fault condition identification in 96% of cases surpassing existing

tools Provides fault identification AND severity levels

Enables Exception-Based analysis on Big Data DGA databases

Condition- based Maintenance (CBM) Basics - Example

Utilizes Artificial Neural Network (ANN) Programming and an Expert System

ANN trained on data sets that marry pre-failure DGA data with post-failureinspection results

Additional analytic elements include: Harmonic Regression to remove harmonic components in the data, clearly

revealing the underlying trends

Piecewise Linear Approximation to accurately assess gassing rate of change


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Four fault categories are identified High Energy Discharge (HEDA)

Low Energy Discharge (LED)

Over Heated Oil (OHO)

Cellulose Decomposition (CD)

Severity of the fault category is assigned and ratedwithin a 6 level scale

Notifications can be customized by fault category andseverity to enable exception-based analysis.

Diagnostics:



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DGA Visualization example (8 gases)



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Knowledge Management

Or

What to do with my Information?

Knowledge Management!


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Knowledge Management (KM) comprises a range of strategies andpractices used in an organization to identify, create, represent, distribute,and enable adoption of insights and experiences.

Such insights and experiences comprise knowledge, either embodied inindividuals or embedded in organizational processes or practice.(company know-how)

KM efforts focus on organizational objectives such as improvedperformance, competitive advantage, innovation, the sharing of lessonslearned, integration and continuous improvement of the organization.

Data and Information are useful, but nowhere as valuable as Knowledge and Wisdom!Condition Monitoring will only be useful if you know what to do with the Data and

Information to give you Knowledge!


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Moving from Data to Wisdom


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Integration of knowledge from past events into expert system


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Asset Manager1) Avoid Early Life Failures

2) Capture Design and Manufacturing

flaws in Warranty period3) Benchmark OEMs

4) Extend Operational Life of Asset

Maintenance Manager1) Adopt condition based maintenance

processes

2) Eradicate non value add servicecycles

3) Reduce maintenance budget

4) Improve safety for on-site personnel

Operations Manager1) Maintain high system reliability

2) Overload assets when needed withconfidence and dynamically definedlimits

3) Minimize asset time out of servicedue to impact on above

EHS Manager 1) Improve safety for on-site personnel

2) Limit impact of issues on generalpublic

3) Eliminate all risks that could lead tofatalities (No need for business case)

4) Improve compliance to EnvironmentLegislation


Why condition-based Maintenance?


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Challenges of Condition Monitoring

Based Systems


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Challenges of Condit ion Monitoring Based Systems

1) Availability (or lack) of communications infrastructure

2) Incremental spending in front end Capital Expense, varying rate of return

3) Slow adoption of new standards

4) Lean engineering organizations at Utilities, slow process to change currentpractices

5) Training the workforce, education for the industry

6) Few vendors offering integrated CMB systems at Global scale

7) Early stages in real-time analytics and dynamic modeling for power systems


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Condition Monitoring is like insurance.

Everybody agrees its prudent to have it, but nobodywants to pay for it.Anybody could see the benefits, and

Somebody always asks why it was not fitted when its all

gone wrong


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References

1) WD IEC 61850-90-3

2) Application of Condition Monitoring and Technology within National Grid(UK), CarlJohnstone, National Grid, UK. CIGR-089 2012 CIGR Canada Conference

3) http://www.businessdictionary.com/definition/maintenance.html#ixzz2VFFiFfwd

4) http://performancealliance.org/Portals/4/Documents/Committees/NonResQM/OM_5.pdf


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Q & A

Thank you for your time