Estimating maintenance costs of a wind turbine pitch control system

Wind turbines are nowadays the principal source of wind energy production. However, the technical information publicly known about these machines is still very scarce. Indeed, information related to failure modes, unavailability and maintenance costs of these systems remains confidential and only is held by manufacturers. To be able to optimize the efficiency, to guarantee the security and to negotiate better warranty and maintenance contracts, it is necessary to know more information about the operation and maintenance and replacement costs of subsystems of a wind turbine. To this end, this paper presents a short literature review of what has been published so far about this issue, and, based on two years of operation, analyses an active power control system of 21 identical wind turbines, installed in a wind farm in Portugal. The emphasis of this study is on the operation, availability and maintenance, and replacement costs of the active pitch control device, which automatically manages the position and operation of blades according to wind direction and speed, thus maximizing the electrical power gathered from the natural forces. Moreover, the paper provides an estimation for the total maintenance cost of this device, one of the most important components of the wind turbine, thus allowing wind farm companies to carry out financial and economic analysis of maintenance contracts that probably will be the rationale for better contract negotiations with manufactures. The result and the analyses that have been reported may also contribute for further studies on the reliability and maintenance policies of wind turbines.This work was financed with FEDER Funds by Programa Operacional Fatores de Competitividade – COMPETE and by National Funds by FCT – Fundação para a Ciência e Tecnologia, Project: FCOMP-01-0124-FEDER-022674.info:eu-repo/semantics/publishedVersio

Simulation approach for an integrated decision support system for demand responsive transport planning and operation

Rural areas are becoming more desert from day to day, leading to complex dispersed and scarce demand patterns for public transport. As a consequence, conventional transport services are becoming less frequent, reducing levels of service (e.g., low occupancy rates, usage of old vehicles). With rigid predefined routes and schedules, they are inappropriate to operate in such environments. Demand Responsive Transport (DRT) systems have been seen as an interesting alternative solution, providing flexible transport services to meet trip requests. This solution has already been adopted in several countries as a way to increase user’s mobility and mitigate social exclusion. There are however some issues concerning DRT scheme design and evaluation requiring further developments. Namely, there is still a lack of adequate tools to support some of the strategic and tactic level decisions that must be made at the design phase. In this research, we propose an Integrated Decision Support System (IDSS) and general action methodology that will allow achieving better planning decisions and allowing the evaluation of alternative scheme designs prior to its implementation. The IDSS and methodology are based on an event-driven simulation framework which emulates real-world customers’ behavior and vehicles movements. The paper will concentrate its analysis on this framework. An illustrative numerical experiment is presented and briefly discussed.The authors acknowledge the financial support provided by the European Union through FEDER - "Programa Operacional Factores de Competitividade" (POFC) and by the Portuguese Government through FCT - "Fundação para a Ciência e a Tecnologia". Research grants: FCT/TRA/72871-2006 and FCT/SEN-TRA/116216-2009

A cost-benefit analyis of an intelligence and demand-responsive public transport system for eldery and disabled

The current road public transport systems in Portugal are not suitable for most of its inhabitants, in particular those who suffer of reduced mobility. This inadequacy is mainly due to the lack of flexibility of the transport services provided and the poor level of physical accessibility (pathways and in-vehicle facilities). This study aims to estimate the effects of the implementation of public transportation systems designed to meet the specific market of public transport demand of people with reduced mobility (e.g. elderly and disable). The main factors affecting the system must be translated into a number of criteria and indicators to be included in the evaluation of potential transportation projects in this area. The study is based on a literature review and focuses on the analysis of externalities and decision making about public transport. From this review it is intended to develop an analysis of the externalities of the projects. It will be also discussed the cost-benefit analysis for the project aimed at ensuring the sustainability of a transport demand for people with reduced mobility (TDPRM)

Integrating simulation and business intelligence analyses for tactical and strategic decisions in transportation systems

Transportation planners, analysts and decision-makers usually make use of simulation tools in order to accurately predict the performance of new practices and policies before their implementation. Additionally, most of them, recently introduced new auxiliary Business Intelligence decision support tools in order to transform their available huge amount of real operating data into timely and accurate information for their decisions. Although both of those types of automated decision support are valuable, very few attempts were already made by researchers to integrate them into a unified tool. This paper proposes a conceptual framework for a decision support system that integrates both of these technologies, simulation and Business Intelligence, in order to enhance the overall practical interest for its usage by taking advantage of the foreseen synergy of the integration. The paper discusses the potential interest of the proposed integration, and identifies a set of questions that can then be answered with effectiveness and more efficiently than before

Specification of a debureaucratization model in teaching: case study

Trabalho apresentado em ELEC 2018 – European Lean Educator Conference, 14-15 novembro 2018, Braga, PortugalNowadays data is crucial for any organization and its success depends on how it is managed. The management´s information process of the education system in general, and of an education institution, in particular, is a complex and bureaucratic process, where occurs information´s fragmentation. In order to counter this reality, people should be encouraged to simplify procedures by adopting a culture of continuous improvement. On the other hand, it is suggested an appropriate infrastructure that enables not only data integration but potentiates its transformation into knowledge. The data simplification and computerization will remove the bureaucracy associated with the management of processes, streamlining and translating them into the creation of value in the education sector. It should be noted, however, the importance of ensuring that the proposed solution is based on the needs and characteristics of each education institution, and the education system, in general. There is also the need for the involvement of all participants, as well as the recognition of their perceptions because these are influential factors in the successful implementation of the change process.N/

Sustainable public transportation from a total cost of ownership perspective

Green transportation advocates decreasing use of private motor cars, the increasing use of walking, bicycle and public transport. Since the main factors for people who desire to travel are cost and time, the use of private cars has increased with significant negative impacts on environment. Total Cost of Ownership (TCO) is an analysis meant to uncover all the lifetime costs that follow from owning certain kinds of assets. In the near future, more people will be challenged to use a combined set of transports to minimize total transportation costs. In this study, a set of combined types of transportation (private cars, train and bus) was simulated by using a traffic simulation software and the TCO for a case of a route in the North of Portugal was calculated. Criteria for the evaluation of the different types of transportation included conventional cost of traveling (internal) and value of travel time and value of environmental aspects proceed by the CO2 emissions (external costs), all translated in monetary values using estimations of the value of time and of environmental impacts. The results showed the importance of the value of time estimation and confirmed public transportation as the best option under both conventional and extended TCO point of view

Maintenance decision making

In any management process, decision making assumes a very important dimension. Complex systems are commonly fed with large amounts of data that are quickly made available to experts and industrial engineers who, in most cases, are not provided with adequate decision support tools. Therefore, the quality of their decisions heavily relies on their our quality and experience, making the complex systems management planning, particularly in maintenance planning, a very difficult and subjective process, by tendentially diverting analysts from the main decisional aspects. In order to overcome these difficulties and subjectivities, this paper purposes a set of methodological guidelines based on fuzzy set theory to be applied in the planning processes, leading to optimized and more realistic results

Outlining fuzzy decision making in maintenance planning

In any management process, decision making assumes a very important dimension. Complex systems are commonly fed with large amounts of data that are quickly made available to experts and industrial engineers who, in most cases, are not provided with adequate decision support tools. Therefore, the quality of their decisions heavily relies on the quality and experience of them. Indeed, in general, such great availability of data makes the complex systems management planning, particularly in maintenance planning, a very difficult process, by tendentially diverting analysts from the main decisional aspects. Sometimes, unrealistic decisions come out from the process. In order to overcome these difficulties, this study purposes a set of methodological guidelines based on fuzzy theory to be applied in the planning processes, leading to optimized and more realistic results. The applicability of these guidelines is illustrated by a numerical example in the maintenance planning context

Economic and risk factors of a transhipment system using electric cargo bikes for urban courier services

The distribution of goods in urban areas is a major challenge for managers in the public and private sectors, due to population growth, high density in large urban centers and, in many cases, lack of planning in urban cargo transport systems. In this context, the objective of this paper is to propose a novel collaborative urban cargo distribution system for logistics service providers, based on a transshipment terminal and usage of electric cargo bikes, highlighting the main aspects to consider on estimating its beneficial economic and environmental impacts in terms of emissions and the risk factors of the investment. The evaluation of this solution may be based on applying simple vehicle routing heuristics for assessing the distance travelled, costs and emissions. Also, a more sophisticated cost model is proposed to estimate the economic viability and risks associated to the use of electric cargo bikes. Finally, risk aspects can be evaluated through a structured methodology including both qualitative and quantitative approaches.This work has been supported by FCT -Fundacao para a Ciencia e Tecnologia (Portugal) within the Project Scope: UID/CEC/00319/2019

RAM factors in the operation and maintenance phase of wind turbines

The high complexity of technological systems and the increasing requirement and competitiveness of markets request the implementation of adequate management strategies for these systems in order to improve their availability and productivity. In this context, RAM factors constitute a strategic approach for integrating reliability, availability and maintainability, by using methods, tools and engineering techniques to identify and quantify equipment and system failures that prevent the achievement of its objectives. This paper presents the most relevant aspects and findings of a study conducted for assessing the operational performance of a wind turbine system installed in a wind farm in Portugal. The study was based on the analysis of the behavior of states defined for each individual wind turbine over a period of two years, and was aimed to identify and evaluate the effects of RAM-type factors. Given the structure and nature of the data, a Markov Chain approach was adopted for this evaluation. The main finding was that the usage of a particular technique (the frequency and duration technique) is adequate to effectively evaluate the overall performance of the wind farm and find opportunities for improvements.This work is financed with FEDER Funds by Programa Operacional Fatores de Competitividade – COMPETE and by National Funds by FCT – Fundação para a Ciência e Tecnologia, Project: FCOMP-01-0124-FEDER- 02267