Reports illustrate strong transmission system health
by Lisa Meiman
On June 2, the Asset Management Program Improvement Project team, or AMPIP team, unveiled the first set of risk reports on some of Western’s critical assets, illustrating quantitatively, for the first time, the health, importance and risk of Western’s power circuit breakers, power transformers and transmission line segments over 100 kilovolts.
The initial data confirmed what Western maintenance crews, power operations dispatchers and managers have asserted for a long time: Western’s system is in good shape. “The probability of our assets failing due to lack of maintenance is very slim,” said Project Manager Don Roberts.
These Official-Use-Only reports cap a two-year effort that involved dozens of employees from power marketing, power operations, maintenance, transmission system planning, information technology and other functions. But the two-year effort is just the beginning for Western’s Asset Management program.
Roberts, who works out of Folsom, California, in Sierra Nevada, explained the importance of this achievement, “This is the biggest milestone in the project. These are the first annual risk reports generated by the project. They will become the benchmark for the program and also the baseline data for asset condition and risk ranking.”
Upper Great Plains Regional Manager Bob Harris, who is also the project’s senior sponsor, added “AMPIP’s reports for Western’s transformers, breakers and transmission line sections are a major step forward, culminating an enormous amount of work. It is very exciting to have this type information available to aid in our maintenance and replacement planning for these three assets as they represent about two thirds of Western’s physical assets.”
Using Maximo, Western will run these reports annually, providing a regular and consistent “snapshot” of these assets agencywide. The results will trend asset condition and risk changes over time and provide valuable input into regional system planning, project justifications and budget development and requests. “The grid is constantly changing. Over the year, projects will be completed, assets will be purchased and replaced and system information updated. We will need to do analysis every year to capture the changes to the assets and the system models.”
List, sort, rank
The dizzying arrays of data contained in these reports are surprisingly simple to understand, even for the less mathematically inclined. The data in each asset class can be organized by four sort options for each region and Westernwide:
- Health index, or HI
- Probability of failure, or POF
- Risk score
HI data includes condition factors evaluated by maintenance crews during their inspections and tests. This data measures the current “health” of that asset based upon an on a scale from zero to 100.
POF is a more advanced condition measure that builds on the asset health index by adding individual loads and stresses and historic performance of the asset class. Or, in other words, the percent chance that the asset will be unavailable for service within the next year. The higher the POF, the more Western should consider additional replacement or maintenance strategies.
“Asset management is not going to change how the crews conduct maintenance, but it can help bring focus to prioritizing maintenance tasks,” said Roberts. “It is going to complement reliability-centered maintenance by showing where the lowest health assets are and what factors may be driving the lower health.”
Consequence data provides a relative measure of the impact of an asset being taken out of service, regardless of the reason. The higher the relative consequence score, the more important the asset is to Western and its customers both economically and for reliable customer service. Consequence data was created from scratch by sub teams made up of employees from power marketing, power system operations and power system planning. This data is the main reason the reports are OUO.
Then by multiplying the POF and consequence scores, the asset’s risk score is calculated. “The relative risk score tells us which assets within that asset class are at the most risk,” said Roberts. “Using these numbers, we can help make decisions on where we should be spending our money. Western can better decide how to mitigate the risk, determine acceptable risk, and help define the agency’s risk tolerance when it comes to these physical assets.”
For instance, if you have a higher-risk transformer, a system planner can use this data to help determine if the risk needs to be lowered and how. Is it in poor condition and in need of replacement or aggressive maintenance? Or is the health good but the consequences of losing the asset are driving up the risk score? In that case, the system planner might consider adding a redundant transformer or redesigning the path to reduce the risk.
“This project goes a long way in helping Western begin to use data-driven, risk-based analysis to support future projects and project justifications,” said Roberts.
Room for improvement
Although the team is satisfied with the data available for circuit breakers and transformers, the transmission line health index information needs work. “The transmission line segment data is misleading and not usable for decision making,” said Roberts. “The primary data point for the health index is age of the whole segment, breaker to breaker, which may not represent the age or health of its individual structures or components. And what the other two asset classes have taught us is age doesn’t necessarily correlate to health.”
Fortunately, the granular structure and component data is already available at the regional level. Unfortunately, each region uses its own database for record keeping and to identify deficiencies and asset condition.
Creating one database with standard condition information is the main goal of the Transmission Line Inspection Solution Project led by Program Manager Bill Bailey, in Lakewood, Colorado. “Every region uses different software to track information about structures and conductors and also uses its own rating codes, known as deficiency codes, to identify the health of a component,” said Bailey. “Our project will implement one application to track information and use one priority rating approach to identify deficiencies.”
The Transmission Line Inspection Solution Project team, made up of employees from maintenance, IT, geographic information system and Maximo, plans to have a new application in the field by the end of the year. The team will also crosswalk historical data into the new database using the standardized ESRI maintenance priority rating system.
Though the AMPIP team has reached the final stage of the four-stage project, there are significant close-out items that need to be completed before the project is officially finished. The team will spend the remainder of 2014 transitioning the project to a full-time program with a new office under Chief Operating Officer Tony Montoya and asset management specialists in each region that report to the regional maintenance manager. “There is lots of work left to do,” said Roberts. “We’re still working with the Enterprise Risk Office to develop an asset risk register; we have to improve our transmission line metrics to the structure level; and we need to develop a new asset management order and manual for the agency.” Also on the to-do list, are IT improvements to provide for a more efficient and sustainable process.