Statement of the Problem
A new model for availability growth has to be generated in order to factor in the systematic risks that occur before a complex system construction . The new model has to be created because of the new technology to be used in new generation offshore wind farms. The wind farms are supposed to improve the investment options and therefore to be on the safe side to do so, a new model has to be put in place for testing purposes of the systems.
There are a number of risks involved in developing new generation wind farms. This is because of the uncertainty of the systems which are brought about by unpredictable risks. It leads to loses in investments and a waste of resources in creating a system that is bound to fail, it also delays the significant goals that the wind farms are meant to gain and therefore creating a model is viable to assess the risks and predict the most successful and economically viable decision.
There is need to consider the risks involved in the creation of new generation wind farms. This is the reason for innovation in that a new model is brought up in consideration of the associated risks in offshore wind. Therefore the new model is put in place as a factor of risk management in the offshore wind as innovation takes place.
There is need to come up with a new availability model for wind farms. This is because there is empirical evidence of a low performance of new farms. New farms seem to be experiencing these problems due to lack of enough support in availability models. This has been known after the intervention to bring up availability growth later in the operational phase. The intervention improves the working of the wind farms to achieve the target goals, but the problem is that it comes late and hence extra efforts have to be initiated.
The technicality in coming up and introducing availability in the wind farms in order to improve performance is that the structural make up has to be redone. This means that the whole project has to either be brought down or be expanded outside the predefined model. This may bring positive or negative results in the performance of the wind farms
The late introduction of availability model also has budget implications. This is because the new modifications in the already planned model are not budgeted for in the current wind farm construction budget. Therefore, funds have to be released in order to cater for the new modifications. It means that the construction of the wind farm becomes expensive in its utilization phase, which also means that its economic relevance goes below the expected values. This can be an inconvenience to the wind farm construction goal and therefore there is need to have a new model that will enable the construction of new generation wind farms without the above mentioned risks.
Therefore, having a model for reliability in construction and use of new generation wind farms will enable the consistent availability of energy in the UK. The construction of new generation wind farms will be economical and there is a high tendency that they will meet the proposed goals without the need for further intellectual and financial investment. This is meant to cut costs of construction and further improvement in the already constructed wind farms. There is also a high chance that there will be no disruptions of energy output from the wind farms for need to close the plants down in order to effect an improvement plan. Risks are bound to be averted and therefore the goals of the construction of the wind farms will be achieved.
The importance of a reliability model is that the construction process will be without flaws. This is because there is an existing working plan for reference purposes. The model has a set budget, set measurements in the technical and measurable perspectives and that it gives the expected output of energy as well as the time limit of construction. Therefore, it is an important tool in coming up with a new generation wind farm since it has all the necessary logistics in mind. This is the main reason that crafting an availability model is encouraged to provide reliability for construction of wind farms.
Available Data
The base for coming up with an availability model considers the need for reliability growth. It means that the model is not only limited to engineers that are in need of for a design model, but also for those that require data on the essence of financing the project and those that will be involved in the operation of the system. The target is to involve the needs of the various stakeholders so as to come up with an availability model that will help in the construction of wind farms that will be usable both to operators and the target task of availing energy.
It is important to highlight the need for the technical aspect of the availability model since this will be relevant in construction. The need to have an availability model in the early stages is to ensure that the problems presented during use are avoided. There are instances when equipment may break down and you find that Original Equipment Manufacturer warranty is limited. An early start therefore ensures that the equipment is catered for and all the necessary information is brought on the table to ensure that the construction is complete and up to required standards.
The model proposed is in a single framework that ensures that there is space for integration between interventions that will cater for improvement of reliability and those that will cater for reduction of restoration times. There is the essence of condition monitoring as it ensures that there is data on the logistics required in the maintenance of the availability system. Model outputs therefore will provide informed data on the functionality of turbine operations on energy production in the farms.
Technical availability of the system is one of the vital criteria that will be based on. This is in consideration of the uptime operation strategy and the downtime operation capability. There are a number of subassemblies that contribute to the operation of the system and therefore the more reliable, they are, the better the performance of the system. During planning, the subassemblies have to meet the target operational terms in order to be as effective as required. The operation of the system is divided into two vital phases which require prior planning in order to meet the planned goals of each phase. The phases are uptime and downtime performance models which are affected as explained below.
Through consideration of the factors that affect the two models of operation, the system can be made available through modification and correction of the flaws. The factors that affect the operation models are known as triggers as they influence the reliability of the subassembly by introducing systematic risks into the system. Therefore the factors that influence uptime include design inadequacies, Defects in manufacturing and errors in operations.
Design inadequacies occur due to the errors made in the design of the system. The errors can be because of the insufficiency in the specific conditions required in operation of the system or the environmental factors that show the actual conditions of operation of the system. The risk of design insufficiency comes in the placing of the offshore turbine. There are turbines that can be located in the bedplate and hence take up vibration while the new generation turbines are large in size and they mostly operate offshore. This means that the levels of vibration can be mistaken and bring about errors due to design insufficiency.
The placing of the wind transformers and the size of the gearboxes also matter to the operation of the wind farm. Allocation of the gearboxes depend on the size, this means that the selection of smaller or larger sizes will affect the operation of the wind farm in terms of efficiency. It is known that smaller gearboxes are more reliable than the larger ones, therefore selection may affect the final design of the system.
Defects in manufacturing this occurs due to assumptions or ignorance. There are problems that may occur during the production process control together with the manufacturer’s quality management. Errors in manufacturing can occur during the production of the turbine blades that require time, precision and specialized material. Since the process is involving in terms of resources and time, the manufacturer may become sluggish and hence prone the product to errors which will later affect the operation efficiency of the turbine.
Errors in operations occur during the process of installation or maintenance. These are the times when the engineer subjects the system to human error, where the essence of tough timelines or the complexity of the task leads to a fault in the process. An installation defect is the main contributor to the system uptime reliability. There is also the prevalence of downtime operations, which is brought about by logistical factors.
The main factors that affect downtime operations which are aimed at restoration of the system are the lack of resources and the ability to access the site. This means that in order to keep the maintenance phase in schedule the above resources have to be available at the required time. Access to the site can be marred by heavy or unstable waves on an offshore wind farm.
Therefore the replacement of gearboxes will delay and hence increase the time required for repair and maintenance. Access can also be hindered by heavy winds on the wind farm and hence the delay in maintenance. There is equipment that is quite expensive, therefore it has to be taken from other departments. It means that the schedule of the owner of the equipment will be followed. This instances lead to further delay and therefore the downtime gets extended.
The conceptual framework of the uptime and down time operational factors.
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Probabilistic Model
The probabilistic model used in this paper was Weibull distribution model. It is because the Weibull distribution model is a continuous probability method. The model identifies through statistical data analysis the probability of a failure to occur. This probabilistic model is important in that the system has to be checked often due to the nature of work and operational terms that it accomplishes.
Statistical Procedure for Estimating Model’s Parameters
The parametric model is based on the subassembly failures as classified in shocks and wear-out. Therefore the shock-dominating initial period is named Stage 1 while the second shock and wear-out period is named Stage 2. The lifetime of the wind farm system will be broken into various intervals and the signal time will be the main factor to indicate the time for maintenance.
Software Used
There is need to monitor the system and therefore a method has to be effected for the same. This is the reason that the Condition Monitor (CM) is initiated to check the system performance. The system is able to detect a certain amount of wear-out in the system. This message corresponds to an observable degree of wear out in the turbine especially on the bearings and therefore the system sends a signal to the operators. The CM is important in ensuring that maintenance operations can be delayed through derating of the system to operate in a current state as maintenance operations are planned and effected.
Estimation Results and Discussion
The system is viable to enable the continuous working of the wind farm until repair and maintenance is put in place. It is important to ensure that an availability model is created so as to have enough data for comparison purposes. This way, the construction and maintenance and efficiency of a wind farm can be tangible to the UK.
References
Zitrou, A., Bedford, T., & Walls, L. (2016, August). A Model for Availability Growth with Application to New Generation Offshore Wind Farms. Reliability Engineering & System Safety, 83-94.
