Asset Management Plan For Power Production Industry: Reliability And Sustainability

Asset Management Plan

Asset management represents a framework that utilizes the asset in the allocation of the capital of an industry with its operation and maintenance budget. Engineering widely depends on this asset management in any plant or a production industry. Each and every product that is obtained should be calculated on the regular basis and it is compared with the initial capital.  The challenge mainly occurs in the technical knowledge of these assets to take any business decisions. Many types of management techniques and framework are being adapted in the several production industries or plant. This paper deals with the asset management that is done in a power production industry. The industry named SA Power Network which is in Australia is reviewed in this paper. SA Power Network is responsible for the power transmission and distribution within the South Australia. The distribution network in common, inaugurates from the 66kV and 33kV connection points at sites that is shared with ElectraNet behind the customer’s point of supply. The substation transformer is the key component for an asset that has 33kv and 66kv serial bus connection, insulating oil, switch gear, transmission substations etc. Transformers are the most important component in the field of electrical engineering which could have a long life and said to be a cost intensive component. These transformers constitute an electrical supply networks. A transformer works on the principle of electromagnetism to modify an AC voltage to another (Marttonen, Monto and Kärri, 2013).  The concept behind the ageing of the transformer and gas analysis in the insulating oil and how an asset manager should handle the situation is also dealt in this paper. The analysis method named Failure Modes and Effects Analysis (FMEA) is explained, which is an analysis technique that reduces the risk factors. This is a very effective way that increases the reliability of the transformer that is widely used in the power grid system.

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As a result, an asset manager’s decision making process is anticipated with the risk based management that links the business prerequisite and technical acquaintance of asset circumstance. With the help of these necessities, the asset manager of that industry could be able to analyze the risk, validate the cost expenses that could face the technical requisite of asset condition linked together with the business plan. 

Asset management is becoming more important in asset concentrated industries. This is because industries have become extremely spirited and derestricted markets. In order to increase the business performance, profit margins have become very low that causes business to explore with their new innovative performance (Marttonen, Viskari and Kärri, 2013). Two main aspects are been considered in the asset management: 1) Business performance and 2) Asset technical necessity. Though, this falls in the same category they disagree with each other. For instance, economic prerequisite should be done only at the minimum cost for the maintenance of the asset management. But cutting the cost of expenses could affect the quality of the asset’s performance and thus this could have a fall in the revenue of the business profit and thus occurs in the fall of the business. Hence, there should be a balance between both the financial and the performance of the equipment (Holschbach and Hofmann, 2011). This is popularly said to be “optimization”. In this paper we are going to deal with the production line asset management of a transformer. Transformers are the most important component in the field of electrical engineering which could have a long life and said to be a cost intensive component. These transformers constitute an electrical supply networks. When we take a power plant transformers play a major role either in the transformation line as well as for the input power supply (Marttonen, Viskari and Kärri, 2013). The asset management decision making for the power transformer is as follows. 

  • To obtain the level of maintenance of a transformer that is to be carried out in its whole life time
  • Obtaining the inspection that is to be carried out in a power production line. The time line is the very important factor for how frequently the inspections have to be carried out in a production line stating the pipe work, dissolved gas oil sampling, external factors like corrosion etc.
  • Obtaining the transformers that is to be sending for the service and the type of services that is to be carried out in a transformer.
  • Transformers have to be invigorated. It is necessary to obtain the timeline to renovate a power production line. Thereby the timeline to replace a transformer is also noted. 

Loss Estimation

In order to evaluate the loss that is caused due to the transformer, the life time of the transformer is estimated by the commercial and the industrial owners. There is a necessity of the transformers which should be maintained annually and it should be regularly monitored (Catelani, Ciani, Cristaldi, Faifer, Lazzaroni and Rinaldi, 2011). In comparison, if the transformer is getting replaced before its lifetime due to the failure that is caused due to the overloading, then the expected loss could higher that estimated when compared. The power production grid could be affected by many factors. It could be either the insulation fact that greatly reduces the life of the transformer. It could the poor quality of the oil or the moisture content in a transformer or it could be overloading factor too. This could be caused due to the extreme heat of the transformer, which affects greatly in the insulation property. According to the nameplate reading, transformers are designed to operate in a maximum life of 20 years. Transformers that are loaded higher than the nameplate reading have a life of less than 20 years and the transformers that are loaded lower than the nameplate reading have life more than 20 years.

The customer of the transformer should have a special contract with the manufacturer else, the service time for replacing the transformer could be extended. Therefore, utilizing the transformer to a maximum extend without any risk is extremely important (Hoseynabadi, Oraee and Tavner, 2010). It has become critical to study the lifetime models of the transformers, since 30 percentages of the transformer failures is caused due to the ageing. Heavy investments for the transformer were made in the year of 1960-1970 that made the population of the transformer till 30 years. IEEE survey says that the ageing was caused in the transformer after the 25th year. Therefore large transformers end their life at the 25th year and the replacement of the transformers couldn’t be done all at once (Tavner, Higgins, Arabian, Long and Feng, 2010). This becomes tedious and hence there occurs some cause of loss and this should be estimated and tried to be avoided at a maximum extent.   

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Ageing is the most important factor in an electrical plant that causes a greater concern and challenges in the industry. Rather than this Dissolve Gas Analysis (DGA), insulation etc, also plays a vital role in the field of electrical plant. The consumption of the electrical energy is increasing day by day due to the rapid growth of commercial and industrial sectors around the world especially in the urban areas. Due to this, the business is also affected now-a-days (Oh, Rhie, Moon and Tuominen, 2010). The foremost concept of the business is to utilize the asset to the maximum extent. In industries, in order to provide a feasible operation of the system and to utilize the asset properly, regular maintenance and monitoring of the equipment is very important. Any perceivable or non-perceivable one that can be owned or controlled by anyone, which brings out a profit to an organization is considered as an asset. An asset is considered to the ownership of a value that could be converted to cash. An asset is an important factor for the profit of an organization by the products generated by the company. The asset of the power production industry could be transformer, wire, other electrical factors etc. 

Asset Information

Work of an asset manager: 

Asset management has kept its foot prints in the field of electrical utilities. This work is carried out by the asset manager of that particular plant. He got those pressures within him/her in balancing the performance of the system and estimating the cost of the budget and risk within the particular plant (Ridwan, Talib, Ghazali, 2014). An asset manager is responsible for the estimation of all the uncertain events that may happen inside to industry or a plant in order to estimate the budget that could repair it. The work of the Asset manager is representing as follows: 

1) Monopolization: This is said to have an overview regarding the whole business and analyzing the entire network of the plant.

2) Decision key: This is estimating the key decision excluding the other factors of decision.

3) Decision making: This is nothing but implementing the policy. This will focus extremely on developing a strategy.

4) Business network: The entire business must be taken into consideration rather than taking a particular network.

5) Profit making: Business point of view is making a profit from the estimated asset and this should be primarily a main focus that should be a long time profit. The maximization of the short term profit for maximum years by saving the unrequited spending amount, could lead an accountability of the long term profit.

6) Maximum level for service: The safety is the foremost consideration including the environment safety and performance for the best delivery of the end product should be maintained.

7) Risk Management: The 100 per cent efficiency couldn’t be guaranteed. But the maximum acceptable level should be maintained that could save a company or an industry from any risk factors.

A business case or a process is to meet the requirement of client by collecting the related and structured activity inside the industry or a plant, which promote a service or a product. Key Performance Indicators (KPI) is said to be followed by many data driven organization that motivates them in their efficiency. It is defined as the “measures that helps to monitor a company’s performance by the manager and spot out the changes that could be done in order to increase the efficiency”. The processes are designed in reducing the spending cost but increase in the efficiency of the product or produce the profit from the increased efficiency (Jagers and Tenbohlen, 2009). This could add value to the business case. Objective, source, performance criteria and the action plan are the key roles to be performed to make a KPI meaningful. The foremost endeavor of a business is, “utilization of the assets to a maximum extend. The business clutches the assets regularly, which led to the production of higher revenue. However, the condition could get worsen due to this. At the plant or in industries, regular monitoring and control should be maintained, in order to utilize and sustain the asset properly. The investment in this monitoring and management will prolong the life of the asset (Goodden, 2009). Hence, a balancing act should be maintained that utilizes the asset at a maximum and lowering the cost to the minimum, so that the business could be enhanced. 

Industry Name: SA Power Networks

Strategy plan: Asset Management Plan 3.2.01 Substation Transformers 2014 to 2025 

SA Power Networks is a sole industry in South Australia that delivers the electricity from the high voltage transmission network connection points, which is operated by ElectraNet. The power lines have the network of about 87,500 kilo meters (Mariut, Filip, Helerea and Peter, 2010). They have business customers of about 830,000 in South Australia. The Strategy of the Asset Management is: “to revamp the capital investment through targeted substitution of assets, depending on assessment of asset condition and risk, and also seeks to provide sustainable lifecycle management of assets through the use of condition monitoring and life assessment techniques.” For the successful implementation of the substation power transformer asset management plan, it is necessary to create, develop and implement the planned stages. Through this SA Power Network industry meets the standard of the industry and give and optimum satisfaction for the stack holders and the handling customers.  Management of the substation power transformers in managing the asset is the industry’s main focus until the end of the life cycle of the transformers (Marttonen and Kärri, 2013). If any issues are to be found in the previous stage then the stage is necessarily corrected in the next proceeding stages. Through this feedback, the feasibility and reliability of the life cycle plan of the substation transformers could be increased which thereby increases the efficiency of the power distribution networks.

Substation Power transformers transfer the transmitted voltage in the form of the distribution voltage, which is situated at the mass electricity supply substations. About 696 substations are found in that station, which is under the service condition. The average unit replacement cost could be at the estimated level of about $260,000 to $1,640,000 that is found to be greater than the estimated cost (Allee, 2008). The asset management plan in this particular industry is carried out by regular monitoring and maintaining the condition and performance of the transformer that will extend the life term of the asset life and this will surely helps us in achieving the long term replacement plan.

SA Power Network provides certain key aspects that satisfies the risk management principles, provides the customers satisfaction, transport most favorable returns to the shareholders, provide environmentally friendly surroundings which provides the safety situation for the people around as well as the employees. According to the history of the SA Power Networks, the transformers used here are highly reliable with the low service failure rate. The situation that arises to the service failure is due to the supply disruption to the maximum amount of customers, up to 20,000 and shattering failure that is caused due to the explosion of the transformer or due to the oil fire or due to the issues that are caused by the atmosphere. The replacement of the transformers could take about 5 to 20 days, although the sufficient spare parts are easily available in the industry. With the help of the utilization of the Insurance spare unit that is held at the industry store the failed transformers could be easily replaced (Al-Turki, 2011). The unit to be replaced enters into the Insurance spare store as a spare part. About 12 months time will be required for purchasing, manufacturing and delivering a novel unit. For the last five years there have been a maximum number of failures in the power production line. With the adequate monitoring of the transformer condition, the failure of the transformer could be avoided. The risk and the cost of failure that is caused by the transformers could be avoided due to this continuous management plan. From the period of year 2014 till 2025, a total of 135 substation power transformers are programmed to be replaced. 

The estimated expenses is generally in line with the average annual expenditure over the last 5 years, ±$0.78million or $13 per cent. The greater part of the expenses, around 83%, recounts the non-estimated replacement due to certain faults and failures over the past 5 years. 

The replacement of the substation transformers and the expenses plan is available in the Risk management framework of the SA Power Network industry depending on the asset past information and general guidelines (Amadi-Echendu, Willett, Brown, Hope, Lee, Mathew, Vyas and Yang, 2010). The industry tries to maintain the records of the asset management plan that helps them to continue their development process in the following manner:

1) Asset situation as well as imperfections that includes the category condition ratings/scores

2) Asset mistake as well as malfunction that includes aspects that causes the mistake/malfunction

3) Estimated amount that they spend due to the replacement which includes the labor as well as the material cost. 

The detailed explanation of the asset management plan that is carried out at SA Power Network industry is mention in the figure given below. The plan of the substation power transformers in the power distribution process ensures that the transformer is getting operated in a safe, secure and an environmentally friendly condition. The plan between the year 2014 and 2025 is stated ensuring a dividend profit for the shareholders of the SA Power Network. A new management plan is currently activates at the SA Power Networks that is mentioned by the Condition Monitoring and Life Assessment (CM&LA) Methodology in the asset management approach (Aoudia, Belmokhtar and Zwingelstein, 2008). The Condition Monitoring and Life Assessment at the present scenario replace the current carried situation plan in the asset management. This method provides an approach that is highly reliable, economically safe in using the asset in the power substation transformer.

The term Risk management means any systematic method that logically identifies, analyze, assess, treat, and monitor the risk associates factor in an event or an activity (Baglee and Knowled, 2010). This will enable the industry or the plant to minimize the loss factor and maximize the opportunity. The processes of the risk management are as follows:

1) Categorize the activity or a situation that necessarily causes the risk event

 2) Analyze the type of risk that has happened in the particular scenario. Potential consequence that causes the risk to occur and their level of magnitude is estimated.

3) Priority of the risk is estimated and determination the management priority.

4) Control procedures are taken to neglect the risk factors.

5) Monitoring and reviewing the risk management system is necessarily carried out.

Risk assessment and management is used in the decision making process by the SA Power Networks, in order to estimate the capital and expenditure of the network during their maintenance and transformer operation. Probably the transformer failure is caused due to the following reasons:

  • Mechanical failure – This occurs normally due to the component failure of the distribution network.
  • Insulation failure – This happens due to the poor oil quality which is used as an insulation factor (Banks, 2009). This could also be caused by the short- circuit of the transformer. In order to maintain the quality of the gas in the insulation oil Dissolved Gas Analysis (DGA) test is carried out which is explained later in this paper.
  • Thermal failure – Caused due to the problems caused by the cooling circuit or due to the large resistance associations or overloading.

Performance which is carried out by DGA (Baños-Caballero, García-Teruel and Martínez-Solano, 2010) in the insulating oil with the oil sampling analysis test is used as an evaluation of the transformer health. Any malfunction that happens inside a transformer and its required equipment could generate some gases inside it. Therefore, the identification of these gases and the information obtained from that could be very useful for some maintenance and prevention. There are many methods to estimate these gases but the Dissolved Gas Analysis (DGA) is said to be the most efficient. In order to measure the concentration of the dissolved gases, there are two process carried out: 1) Sampling the oil obtained 2) Testing the samples. This DGA analysis should be carried out at least a year and the details should be compared with the previous analysis data. There are several standards such as ASTM D3613, ASTM D3612, and ANSI/IEEE C57.104 (Rowland & Bahadoorsingh, 2008), respectively to evaluate the result.

The main causes of the formation of the gases are due to the electrical strife and thermal putrefaction. At some point, each and every transformer could produce gases in usual working temperature. The transformer insulation process is done through several mineral oils which is said to be the composition of several hydrocarbons. The decomposition process in these hydrocarbons is said to be tedious due to the thermal and the electrical fault (Abu-Elanien & Salama, 2009). The basic reaction occurs due to the breakage of C-H bonds and C-C bonds. Hence we could get the fragments of hydrocarbon and some hydrogen atoms.  This leftover mingle with each other and leads to the formation of gases such as hydrogen (H2), methane (CH4), acetylene (C2H2), ethylene (C2H4), and ethane (C2H6). Moreover, due to the cellulose insulation, thermal decomposition or electrical problem generates methane (CH4), hydrogen (H2), carbon monoxide (CO), and carbon dioxide (CO2). These gases are considered to be the key gases and their property is said to be combustible (here the exceptional gas is CO2 which is non-combustible).

This key gas depends highly on their temperature (Broedner, Kinkel and Lay, 2009) which is based on their volume of material at that circumstantial temperature. The small volume at high temperature could produce the same quantity of gases as produced by the huge volume at restrained temperature. This is mainly caused due to the effect on volume. For this reason, the gases which are formed due to the transformer’s insulating oil is used for the evaluation process by comparing with the past history of these transformers (Ridwan, Talib & Ghazali, 2014) in order to find out any faults that could happen potentially or thermally.

Later the appropriate samples is examined and evaluated, the foremost step of the DGA analysis is to find the concentration levels of each and every key gases samples. This could be expressed in parts per million (ppm). It is endorsed that the concentration of the key gases change in time and therefore the rate of change of the concentration is calculated (Jongen, Gulski, Morshuis, Smith, Janseen, 2007). Fundamentally, the probable fault in the transformer could be indicated by the sharp rise in the value of key gas concentration. Therefore it could be said that the result of the DGA analysis gives a sharp rise in the value of the concentration level of the gases. If the normal value limit is surmounted, then supplementary analysis of the sample should be taken and once again we have to confirm where the key gas concentration level is accumulating. When the level reach the action level point then the transformer should be considered and that particular transformer should be removed. Therefore care must be taken while taking this sample analysis test. This particular test involves in the calculation of the key gas ratio and then correlating it with certain limit range.

Table 1: The description of the gas with their limit range and their fault type

Gas Description

Normal Limit(<)

Actual Limit(>)

Potential fault type

H2(Hydrogen)

150

1000

Corona, Arcing

CH4(Methane)

25

80

Sparking

C2H2(Acetylene)

15

70

Arcing

C2H4(Ethylene)

20

150

Severe Overheating

C2H6(Ethane)

10

35

Local Overheating

CO(Carbon Monoxide)

500

1000

Severe Overheating

CO2(Carbon dioxide)

10000

15000

Severe Overheating

TDCG(TotalCombustibles)

720

4630

The Gas Description with their respective key gas concentration is given in the above table. When the value exceeds the normal limit then the sample frequency should be increased with the consideration given to planned outage in near term for the further evaluation. When the value exceeds the Action limits then the particular transformer should be removed immediately from the service.

The Failure Modes and Effects Analysis (FMEA) is an analysis technique that helps in reducing the risk factors. This is a very effective way that increases the reliability of the transformer that is widely used in the power grid system. FMEA technique was proposed in the field of the power system, in order to increase the efficiency of the power system and enhance the economy at a period of one year.  In other words, this can be stated as an important analysis that is carried out to determine and  the risk factors with the help of potential failure modes. This technique is a quality based analysis technique that lists the failure modes, reason for the failure, consequences caused due to the failure and the actions, which are carried out due to the failures (Burns, Sale and Stephan, 2008).  Risk priority numbers (RPN) is calculated by assigning a value for each and every risk causing factor that could lead to failure and severity of the transformer which is given by a formula:

RPN = (Severity) * (Occurrence) * (Detection)  equation (1)

Consequently this also gives the priority to the action that is to be carried out in order to avoid the failure. Higher the value of the RPN, higher is the case of the failure actions that could occur. The main focus of the SA Power Networks depends on the following criteria:

Failure: when a particular functionality is terminated then that case is mentioned as a failure.

Mode of Failure: Behavior of an item that causes failure.

Mechanism or cause of a failure: This represents the cause or the situation that initiates the failure situation which is stated by a term known as “Possible failure causes”.

Effects of failure: Status of an item or a process after the failure has occurred in that particular process.

Severity: It refers to the level of the system affected by the failure. If the severity is said to be in a peak level then it means that the system causes a huge damage which is to be considered.

Occurrence: This refers to the number of occurrences that describes the situation to occur. This is not referred in time but is expressed in terms of the root causes for the situation.  

Detection: This is termed as a identifying the root cause before the failure beings to occur.

Based on this situation or scenario, an algorithm is represented which is shown in the figure given below (Culverson, 2013). For each case, we can able to identify the risk causing factor at an early stage and we can try to reduce or eliminate the cause. The Two control methods that are integrated with  SA  Power Network  are as follows:

1) Prevention Control- this is proposed to reduce the cause and consequences of fault at an early stage before the failure could occur.

2) Detection and Identification control- this particular control is proposed to identify the failure of the process before the problem reaches the end user or the customer.

As soon as all the possible Risk priority numbers is identified, focus should be given to the particular one that increases the priority of the RPN. In this situation, an asset manager should detect the situation and identify the entire problem that causes the failure (Dong and Su, 2010). An asset manager is responsible for assigning the task to the appropriate person and solves all the issues. At once the risk reduction factor is carried out and the RPN rating will be changed automatically.  Hence, the modified RPN is estimated and intended by the envisaged brutality, happenings and exposure levels.

The Asset manager must choose on a consolidation of various activities that imitate plant stacking and stretch levels, support plans, and substitution timetabling. These things are for the most part forbid additionally depend upon the framework (Duffy, 2008) necessities of the gear. It is conceivable that one course to resource cultivation includes changing the working environment of the thing to expand life or reduce prompt disappointment probability. These things are by and large forbid additionally depend upon the framework necessities of the gear (Emmanouilidis and Komonen, 2013). It is conceivable that one course to resource cultivation includes changing the working environment of the thing to amplify life or decrease quick disappointment probability.

Conclusion:

This article deals with the implementation of the asset management techniques with the consideration of the risk management in a power distribution industry. The difference between a transmission and the distribution of the power is described as well as the asset management technique followed in this differential system is also discussed in this paper. Asset manager has the right to make a decision and he/she is responsible for implementing the action plan that deals with the maintenance timetabling, substitute scheduling and level of stress in that particular plant and they are mutually dependent (Fendt and Kaminska-Labbé, 2011) on the system necessities of the equipment. This paper also dealt with the implementation of FMEA analysis procedure, in order to avoid the risk factor that is caused in the power transmission industry with the calculation of RPN priority estimation. The result obtained by this procedure is much satisfied, which leads to the development of FMEA for future purposes. When the data is evaluated by FMEA, ranking should be made with the help of RPN to determine the case of the irregularity of working mechanism. 

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