Life Cycle Management of Station Equipment & Apparatus

The electricity industry is undergoing fundamental change in moving from a regulated monopoly to a competitive industry. Low load growth, over-capacity and uncertainty about the future shape of the industry are creating pressures on the availability of capital and the reduction of operating costs.

Now more than ever, there is a need to optimize the use of existing station plant assets and to develop new, lower cost, more efficient and reliable equipment applications. This new reality is complicated by the fact that a significant amount of station equipment in use today has already accumulated between 20 to 40 years of service. Maintenance costs will rise as the inherent reliability of aging plants starts an inevitable decline.

The objective of this Interest Group is to bring together interested parties to facilitate research that will optimize the life cycle management of station equipment and apparatus and reduce costs through collaboration of methods, procedures, and practices.

Topics and Issues:

• Specifications & Testing
• Condition Monitoring & Assessment
• Maintenance Practices
• Prediction of Remaining Life
• Life Extension Strategies

Current Projects

• Transformers: An In-Service Guide for New and Used Transformers (Factory Tests, Transportation, Storage, In-Service Tests)The objective of this project is to develop a guide to help utility engineers manage commissioning, transportation, and installation of power transformers. The guide will be based on extensive review of relevant publications and standards, survey of utilities to document and summarize common and sensible industry practices, as well as summary and documentation of the results of analysis of all available information, including knowledge gained from experts in this field. In addition, the guide will consider and discuss the relocation of a transformer, taking into account its condition before it is removed, its safe transport, and ensuring it is suitable for service at its new location. This would include all components and insulating mediums (oil).
• Circuit Breaker/Switchgear Specification GuidesThe key objective of this project will be to develop and document technical specifications for circuit breakers/switchgear in the form of a guide documenting the processes and key sections of specification documentation. The documentation would include guides for general specification, detailed rating specification and form of tender detailing required technical responses from the vendor. For the general specification guide, under each heading there would be a discussion of the important considerations for the aspect under the heading followed by typical wording for a specification. The specification will address supply of new equipment only and will exclude turnkey considerations. However the documents will address site testing and commissioning.
• Condition Assessment, Safety Improvement and Life Extension for Metalclad SwitchgearThe main objective of this project is to document the hazards related to possible failure of existing populations of non-arc resistant metalclad switchgear (4kV to 27.6kV) in transmission and distribution substations and generating stations, to provide a means of risk assessment, identify proven mitigation measures that are available for new and existing equipment, and those that are under investigation.
• Instrument Transformers: Specification Guide Including a Summary of Key Standards and GuidesThe objective of this work is to develop a guide to help utility engineers quickly identify and review the key standards and guides applicable to the technical specifications for purchasing all types of instrument transformers. A guide with generic specifications for instrument transformers describing the processes and key sections of instrument transformer specification documentation will also be developed. Optical instrument transformers will also be covered through a utility survey.
• Risk Level Assessment for Operating, Maintenance and Capital Funding ExpendituresThe objective is to develop a guide for risk assessment to assist utilities in making informed decisions when evaluating operating, maintenance and capital expenditures. This project will use theory and practice both within the electric supply industry and elsewhere to develop a guide to common practice, successful practice and best practice. Referencing standard texts, the theory of risk analysis and the role of risk aversion in making decisions will be presented. Through coordination with a number of utility groups (IEEE, the Institute of Asset Management, Doble, etc.) present practices will be collated for analysis and discussion. This will include inputs from utilities from around the world, but will also reference other industries through work at ASTM, ISO and the IAM.
• Total Ownership Costs ReviewThe objectives of this project will be to review Report 3045, “Total Ownership Cost,” completed by the LCMSEA group in February 2009, and revise it to include additional topics and expand on topics already covered, as well as to provide more examples and suggest typical values for financial evaluation (like losses). This effort will also identify and record factors and values utilities are currently using in equipment cost evaluations.
• Gas Insulated Substation SeminarUtilities are experiencing difficulties in expanding properties to accommodate expansions in existing substations (Brownfield) as well as obtaining sufficient property for new stations (Greenfield). One of the solutions is a compact substation design utilizing gas insulated equipment to minimize the space requirements. The objective of this work is to present a one day seminar/workshop on the design considerations of a gas insulated substation (GIS) and the applicable standards.
• Station Equipment Condition ParametersThe project will focus strictly on determining a common set of parameters accepted by utilities for use in assessing equipment condition. The objective would be to establish a simple list of the most meaningful criteria and weighting factors, including test frequency where applicable, for determining the condition and health index of the different substation equipment. The intent would be to establish a reference of the most common criteria utilities could then use in their asset management models.
• Optimal Life Cycle Management for Transformers: A Financial/Risk ModelGiven the complexity of infrastructure, decision making can no longer be based on intuition; it must be based on facts. A good model should include expert (engineer) knowhow and vision related to the asset under analysis as well as financial/risk knowhow (financial analyst) in order to combine actual & future condition of asset, maintenance & investment policies, historical and forecasted behavior of asset as well as relationship between all these elements. The objective of this project is to develop a standalone single asset model to calculate future condition and cost under various user defined scenarios.
• Maintenance StrategiesThe objective of this project is to conduct a survey of LCMSEA participant utilities to document the maintenance practices and identify common (best) practices including overall maintenance strategies (run to failure, time based, RCM based, condition based, etc.) and how they are being applied to each piece of apparatus. This would also capture what utilities are doing – specifically the information being collected, the strategies involved, and changes being implemented or considered.
• Contingency Planning Criteria: On-Site or Off-Site Spare Equipment, Mobile Transformers / Substations, Etc.The objective of this project is to document utility spare equipment/component strategies and existing practices including the application of mobile equipment (substations, transformers, breakers, circuit switchers, batteries, etc.) to meet system contingency criteria. The research should indicate where additional investigation into criteria and/or methodology is required. This would be identified as future work.
• Review and Summary of Key Standards and Guides for Power SwitchgearThe proposed guide will help utility engineers quickly identify and review the key standards and guides applicable to the specific topics being faced by utility staff such as technical specifications for purchasing new switchgear or guides used for testing (factory and field), installation, condition assessment, diagnostics/monitoring of switchgear. This easy to use guide will identify and summarize the key standards and guides related to switchgear, and provide a matrix of topics versus references to guide the user on the inter-relationships, differences and similarities of the key documents used for switchgear specification, design, operation and maintenance.
• Power Transformer Specification GuideThe key objective of this project will be to deliver a Guide with generic specifications for station transformers describing the processes and key sections of transformer specification documentation. The guide is intended for use with large power transformers 20 MVA and above. However, utilities will be able to use this guide for any size transformer with circular windings and core, with the clauses that do not apply identified.
• Development of a Predictive Analysis Program for Evaluating the Success of Reclamation of Mineral Based Transformer OilsReclamation of transformer oil is not only a costly undertaking, but in most cases requires an outage to some part of the power system. It is critical that the reclamation process extend the useful life of the oil at the least possible cost. The objective of this project would be to provide a simple methodology for clients to determine the success rate of reclamation for specific transformers based upon the response of that transformer’s oil sample to a very specific testing regime. Oils which do not indicate successful response to treatment in the laboratory would not respond well to reclamation and should be disposed of.
• Power Circuit Breaker Reference DocumentPower circuit breakers installed in North American power systems are required to perform a wide range of switching and protective duties. The duties range from interrupting high fault currents down to the relatively low currents, associated with switching loads, transmission lines and cables and shunt capacitor and reactor banks. Each duty is unique in terms of degree of complexity and severity and the circuit breaker must have multiple capabilities for each particular application. A variety of circuit breaker types and vintages are in use on power systems, each with their own unique characteristics. Within utilities, managing the circuit breaker asset class is a technically challenging task and requires a level of technical expertise not normally obtained in a degree level power systems program. Many utilities have lost circuit breaker expertise and are faced with the challenge of replacing it. The objective of the project is to produce a self study circuit breaker reference document to assist in the development of circuit breaker subject matter expertise in both new and experienced personnel. Possible uses could be in purchasing, design, asset management or maintenance.
• Substation Ground Grids - A Guide to Additions and ChangesIn-service electric utility and industrial substations, from the smallest to the largest, face frequent change: equipment addition, removal, and replacement; expansion; fault current increase; clearing time increase; loss from natural or unnatural occurrence (e.g., gravel compaction, copper theft); adjustments in standards, practices, codes, and regulations; and, risk profile evolution. A prominent and important feature of a substation is the ground grid. With each substation change, owners are challenged to identify if ground grid modification is needed, what the modification should be, and how to implement the modification in a safe and efficient manner. It is important note that modification does not always require physical change to the grid. Better analysis method, rationalizing assumptions, or decreased clearing time may accommodate change without significant construction. This project is intended to develop design guidelines for ground grids to mitigate such retrofitting concerns and ensure such substation expansion projects are safe and effective.
• Breaker Failure Modes: Causes, Detection and MonitoringEstablish a guideline for data requirements (on line and off line) to perform an assessment of the equipment condition. This guideline would include a table or matrix linking each monitored parameter to the data required and to the failure mode(s) they are intended to prevent. Specifically, only collect data that accurately monitors a condition and only monitor conditions that accurately indicate a potential failure mode. Establish the thresholds and/or parameters which could be useful in developing an on line monitoring program
• Gasket Seals - Best Practices for Leak PreventionThe main objectives of this work will be to identify and summaries the state-of-the-art for gasketing materials and installation practices for new electrical equipment and when regasketing existing equipment in a form of guidelines which can be used in specifications for equipment to ensure that the manufacturers deliver equipment with the least possibility of developing oil leaks once in service. These guidelines will also note the known methods of in-service repair or resealing leaks and the relative costs and success of these methods.
  
  It is intended that the work shall include all the different gasket applications on the equipment (tank cover, manhole covers, bushing flanges, piping flanges, valve connections, CT lead insulators, CT junction boxes, etc.) and note the better materials to use for the different applications. It is recognized different gasket materials may perform better in different climatic conditions (for example, subzero temperatures) and this shall also be addressed in the work. The use of sealing compounds, edge sealants, gasket stops, compression ratios, etc., shall also be addressed.
• Methanol: A New Marker for Paper AgeingHydro Quebec has developed a methodology for using methanol as a new marker for transformer paper aging tests. LCMSEA participants would submit transformer oil samples to HQ for testing and a report would be developed/translated into English to document this method.
• Substation Equipment Asset Health Index: Circuit Switchers, Switches/DisconnectsThe main objective of this work will be to develop an asset health index for Circuit Switchers and Switches/Disconnects, including the following:
   Description of degradation issues for the equipment
   Review of industry best practices in inspection and test regimes
   Description of specific tests and inspections and how they can be rated
   Development a health index formulation for interpreting the overall condition of the equipment
   Assessment of non-condition factors, if any, on overall risk of the asset
   Relating the condition assessment to probability of failure
   Creation of a simple access software tool to evaluate health indices from existing condition data
   Conduction of a survey to gather condition data from utilities
   Analysis and interpretation of the results
   Methodology evaluation and next steps
• Substation Equipment Asset Health Index: Current Transformers, Potential Transformers, Surge ArrestersThe main objective of this work will be to develop an asset health index for current transformers, potential transformers, and surge arresters. This project is expected to allow utilities to better understand what maintenance and inspection activities are necessary for evaluating healthy and condition of assets and how the results of such inspections can be tied together to formulate an overall asset health indicator, how non-condition risk factors can be assessed and related to asset sustainment and, ultimately, investment planning requirements, and how a process along with a tool can be utilized for this assessment. The completion of this project will also lead to improvements in preventative maintenance and result in sound techniques for determining the End of Life of substation equipment.
• Transformer Failure Modes: Causes, Detection and Monitoring - An Information GuideThe operation and maintenance of a transmission type transformer poses a challenge to the owner of such assets. The knowledge and experience of people employed for numerous years has dwindled and decisions on when to test, when to remove from service and when to leave in service can be very difficult without accurate data and knowledge of what the data is telling the owner. Also the long term viability of the transformers is hard to determine without extensive analysis of the condition of these units. These decisions can have a dramatic impact on repair costs, customer costs and the reputation of the asset owner. In Project 3046, a LCMSEA Task Force developed Transformer Failure Mode and Test/Problem Correlation spreadsheets as the first step in the process to provide a guide to transformer owners on how to make these critical decisions. The cost of monitoring devices, in addition to the cost of data collection and storage can be extremely high; therefore it is imperative that asset owners invest in the most effective devices and collect only the most pertinent data in order for their maintenance program to be cost effective. Through the extension of the work already completed this information guide will supply the clients with background information and explanations of predominant failure modes, causes and suggested list of solutions. This information will provide insight into the external conditions which can influence the reliability of transformers, a explanation of what causes transformers to fail, and possible solutions for each failure mode identified on the LCMSEA task force document.

Recently Completed Projects