Protections impact on the availability of a wind power plant operating in real conditions
ABSTRACT This paper addresses a number of aspects referred to availability of the wind turbines operating in a wind power plant. Starting from the experimental data gathered on-site through SCADA systems, and from a recorded data indicating the operation of various types of protections, the causes of unavailability are investigated in terms of determining the impact of the different types of failures as represented by the tripping of the corresponding protections. The results obtained show that the variability of occurrence and duration of the protection tripping for the different wind turbines is relatively high. This impacts on the identification of suitable values and shapes of the failure parameters that can be used to build a reliability model of the wind power plant with probabilistic entries. For this purpose, some indications for constructing a probabilistic model of the protection operation are provided, also taking into account the possible simultaneous tripping of the protections due to mutually dependent events.
Conference Proceeding: On the relevance of reliability assessment for wind farm performance evaluation[show abstract] [hide abstract]
ABSTRACT: To assess the available power output of a wind farm reliability modelling are used accounting for the stochastic nature of the wind energy source, the control characteristics of the wind turbine generators and the related failure and repair processes. Two techniques are adopted with reference to a case study. The first one is based on Monte Carlo simulations and evaluates the power output of a wind farm neglecting the outages of wind turbine generators. The second one evaluates the available power output using a novel technique based on the Universal Generating Functions. The results obtained by the two techniques are compared to evidence the effects of taking into account failures on the expected generated energy as well as on generation costs. It is also analysed the sensitivity of the results with respect to variations of the failure parameters.Universities Power Engineering Conference, 2008. UPEC 2008. 43rd International; 10/2008
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ABSTRACT: The wind power industry has expanded greatly during the past few years, has served a growing market, and has spawned the development of larger wind turbines. Different designs and technical advances now make it possible to erect wind turbines offshore. The fast expansion of the wind power market faces some problems. The new designs are not always fully tested, and the designed 20-year lifetime is typically never achieved before the next generation of turbines are erected. This paper presents results from an investigation of failure statistics from four sources, i.e., two separate sources from Sweden, one from Finland, and one from Germany. Statistics reveal reliability performance of the different components within the wind turbine. The gearbox is the most critical, because downtime per failure is high compared to the other components. The statistical data for larger turbines also show trends toward higher, ever-increasing failure frequency when compared to small turbines, which have a decreasing failure rate over the operational yearsIEEE Transactions on Energy Conversion 04/2007; · 2.43 Impact Factor
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ABSTRACT: The large growth in the wind power industry in the past years mainly focuses on a growing market and the development of large turbines and offshore farms. The high technical availability of wind turbines comes with a greater need for frequent maintenance. Current maintenance planning is not optimized, and it is possible to make maintenance more efficient. Condition monitoring systems (CMS) could resolve the growing wind power industry's need for better maintenance management and increased reliability. Such systems are commonly used in other industries. CMS could continuously monitor the performance of the wind turbine parts and could help determine specific maintenance timing. This paper presents a life cycle cost (LCC) analysis with strategies where CMS improved maintenance planning for a single wind turbine onshore and a wind farm offshore. Case studies are based on real data from Olsvenne2 at Naumlsudden (Gotland, Sweden) and Kentish Flats, in the U.K. The main conclusion is that CMS benefits maintenance management of wind power systems. Improvements can be especially shown for offshore wind farm maintenance planningIEEE Transactions on Energy Conversion 04/2007; · 2.43 Impact Factor