Nowadays, power utilities are adopting Asset Management as their framework in order to cope with the challenges introduced by the privatization and market competition in this sector. Stedin, a Dutch Distribution System Operator recognized the vital role that an Asset Management system has for its organization. Therefore, Stedin, has adopted the publicly available specification, BSI:PAS55, as a standard to perform the Asset Management responsibilities and tasks of their electricity and gas networks. Equipment life cycle and technical performance activities form an integral part of the implementation of an Asset Management system. In this context, Stedin felt the strong need to have access to systematic techniques and guidelines on how to deal with information of equipment lifetimes. In this paper a systematic method, based on Statistical Life Data Analysis, which deals with limited or incomplete life time data of large populations of assets with the aim of obtaining an indicator of the future failure expectancy is discussed. The methods and analytical tools developed in this contribution share a basic framework for decision-making and specify the evolution of the failures of asset population over time.
A method of directly converting wind energy into electrical energy is proposed, called an Electrostatic Wind Energy Converter (EWICON). The method is based on transporting electrically charged particles against the direction of an electric field by the wind and accumulating them at a collector. The electrospray-method is used to create the charged particles. Two implementations of the EWICON and their properties are discussed, one with a separate collector and one with the system itself as a collector. Based on practical considerations, a choice has been made for the latter implementation. This system has been tested and this resulted in a conversion of 7% of the wind energy into electrical energy, whereas conventional wind turbine systems have an efficiency of 45% at their rated speeds. Improvements are suggested that could lead to an efficiency of the EWICON in the range of 25 -30%.Index Terms-energy conversion, wind energy I. INTRODUCTION W5 ,Find energy is a growing source of seemingly endlesslyreplenishable energy which could ease the pressure on fossil based energy sources. However, existing wind turbines have some disadvantages like high maintenance costs, noise, harmfulness to birds and "visual pollution". These disadvantages limit the widespread use of wind energy, not only from an economic perspective but from a public acceptance point of view as well.Constructing wind farms at sea could very well be an efficient solution, because the wind farms would be out of view. Considering the intensive maintenance currently involved with wind turbines, the operating costs of a wind farm at sea would severely limit the economic feasibility of this option. The maintenance arises primarily from the conversion of wind energy to electrical energy via mechanical energy, i.e. the rotational movement that drives the wind turbine. Therefore, a method is needed to directly convert the wind energy to electrical energy in such a way, that very little mechanical movement is required. This way, the operating costs of a sea-based wind farm could be lowered significantly.
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