What is a Good SmartSignal Model?

Presented by Joe Milton Engineering ManagerReliant

Outline

• Reliant generating fleet and OSIsoft PI infrastructure

• Virtual M&D concept • Human factors• What is a good model?• KPIs and other metrics

Generating Fleet Location and Fuel Type

Common Plant Historian -- OSIsoft PI

• 29 PI Servers• 203 interfaces to various systems • 1000+ process displays & reports• 350K tags (real-time data points)

OSIsoft PI took care of history and current value but not what the value should be….

We selected SmartSignal to leverage our existing OSI PI infrastructure and predict…

SS takes data from our PI infrastructure (like vibration, temperature, pressure, etc.) and inputs it into a software model. This model shows how a a typical piece of equipment is supposed to operate over various loads and ambient temperatures.

If the data goes outside of the predictive model, an alarm is sent to the station for further investigation.

Basically, we are making the computer do the work of scanning all of the sensors and instruments in the plant for changes in known equipment behavior.

SmartSignal Predictive Maintenance Tool

Defining WatchList Graphing Terms: Actual, Estimate, Residual, Alert, Incident

Actual (blue) from OSI PI

Estimate (green) generated by SSC models

Residual = Actual - Est

Incident (diamond) multiple samples or sensors showing alerts; drives the WatchList

Alerts (red X) Statistically significant residual value

Typical Results & Additional TermsVSG (green diamond) Virtual

Signal Generation was enabled

Missing Value (blue X) Signal gave NaN value

Smart Signal – Site WatchList

Models

Can see incidents by clicking the arrow button.

SmartSignal – Site Model Detail-Site that you are on.

-Incident List – This is a list of incidents on the models.

-Chart View –The Blue line is the actual PI data and the Green line is the model data.

SmartSignal-Reliant Scope

• 67 coal & natural gas power units across U.S.• Total 13,450 MW power• Rotating & non-rotating balance-of-plant assets monitored• 411 assets, 1174 models• Turn 30K+ sensors to exception-based monitoring• Goals include

– Early warning of equipment faults & process problems– Maximize availability– Minimize forced outages– Improvement of unit heat rates

Reliant’s “Virtual” M&D Center

• Staff of three working 5*8 at their own cubes:– Review WatchList– Email plants when equipment issues are detected– Tune– Build new models– Teach WatchList classes– Document issues and model changes.

• Plant champions – Look at the WatchList– Use log– Deal with the easy ones

Typical Emails to PlantFrom: Lesley Sent: Tuesday, December 09, 2008 1:24 PM To: Scott Subject: A - PA Fan E Alerts

Thanks, Lesley Wierenga

Typical Plant Response

From: Scott Sent: Tuesday, December 09, 2008 10:47 AM To: George, Subject: RE: Avon Lake - PA Fan E Alerts Can we have someone check the LO temps on E PA Fan LO Skid? Looks like a cooling water valve may be closed

Scott

The Plant Champion will commonly use Pi Processbook or Datalink to confirm the item and issue a work order

Example of Full Cycle of a Catch

The oil levels are all good and the filters have been changed. The filters were dirty and the temps are dropping on the motor after the change out.

From: Sent: Thursday, November 30, 2006 1:34 PM

This is a pretty significant movement on FD Fan Motor outboard bearing (about 17 deg above expected currently).

What is a Good Model?

Good Model Brainstorm

What is a good SS model?

It catches changes

True machine issue (catch)

True change but not issue

False

Time scopelast 90 minutes

the next 365 days (really the next 90)

Uses As Found OSI PI data

8 to 40 points

energy and mass flow anologys

little data screening required

True

Not a problem

opperator selectable

Model problem

Seasonal

No misses

It is used

Truth Table (Logic)

SS Catch

True Catch

SS no Catch

Machine issue

SS no Catch

No Machine issue

SS Catch

False Catch

What is a Good Model So Far?

Modeling elements

–It has catches (detects changes)–It has no misses (or few)–It uses as-found data

Human elements

–It has engaged users

MetricsTrue Catches

• Look at the tracking log-equipment/instrumentation catchesMissed Catches

• Long term – Use Power GADS to review major events• Was the system modeled? If not, should it be? Build it.• If modeled, review and improve the model.

No Catches & No Machine Problems• Could be a sign of a good program• Could mean just wait

False Catch• Track issues• Use log statistics and target problematic models

Catches

*2006 catches not a full year

The table shows true catches and false catches

2006 2007 2008Equipment 47 43 82Instrument 40 151 167Model 51 124 81Model % 37% 39% 25%Total 138 318 330

False Catch

• SmartSignal alerts indicate a change from the model data set (State matrix)-– A repair could cause a change– A new season– An operational mode change– An abnormal configuration– Or bad modeling data

Model with False Alerts

30 40 50 60 70 80 9020

40

60

80

100

Parent

Ch

ild

Childc 1 "CW INLET B TEMP TO COND( DEG F )"

Parentp 1 "CW INLET A TEMP TO COND( DEG F )" p 1

c 12

Detailed review of this model data set found that it had two modes. A and B with the same Inlet temperature and A down stream of B

Model with False Alerts

Detailed review of this model data set found that it had two spikes that were included in themodel.

500 1 103

1.5 103

2 103

1.8 10

3

2 103

2.2 103

2.4 103

2.6 103

Parent

Ch

ild Childc 1 "HP TURB THROTTLE 1 INLET PRESS( PSIG )"

Parentp 1 "UNIT 3 FIRST STA GE PRESS( blank )"

Human Factors

• How can acceptance be measured? • Is the user engaged?• What are good KPIs?• How can it be made “fair” for peaking and

base load unit?

Levels of SmartSignal Utilization

• basic level is where the WatchList Team (WLT) serves as an M&D center. Plant responds to WLT email questions about their units and WatchList items.

• the engaged user logs into the WatchList at least once a week (on average).

• The committed user logs in several times a week (on average). They also add information to the log and clear alerts from the WatchList.

• The power user exceeds the committed user level by pressing model issues and providing a dialogue about known plant repairs and changes.

0

5

10

15

20

25

30

35

40

45

50

Basic Engaged Committed Power

20072008

Levels of SmartSignal Utilization 2007 – ‘08

KPI Issues

• Terms like basic, power user work well for a full-year but they did not track seasonal units well

• We moved to a new metric that is much closer to the desired outcome– If you are running- login

SS Login Ratio

Logins

rsServiceHouLoginRatio

“Average number of service hours between logins”

Plant 2007 2008A 122 135B 106 24C 18 26D 138 69E 22 30F 130 35G 16 17H 68 28I 16 16J 114 77K 94 41L 739 229M 882 34N 124 14O 114 232P 666 120Q 132 52R 168 67S 307 191T 358 41

Fleet Average 217 74

Log Entries

2007

• 50% of plants had no log entries

• 78% of log entries were at one plant “C”

2008

• Only 10% have no log entries for 2008

• Log entries more evenly spread across fleet

• 119% increase in total log entries

PlantLog Entry

2007Log Entry

2008

N 1 785G 139 631C 1132 562B 0 296P 0 293M 0 183J 66 91Q 5 81D 16 78K 0 62E 43 57F 4 32R 50 14T 0 13L 0 9S 0 9I 0 3H 2 1A 0 0O 0 0

Total 1458 3203

Lessons

• The knowledge of how the plant should run comes from how it has run (PI data)

• Keeping the messenger alive is part of the task (instruments)• Eliminate variables (do not add them)• Model to detect changes • Exception-based• Statistics-based technologies are not common in plant

environments.• Tools are not complete solutions – People still have to act

Questions?