Development of computer-based simulation for wind diesel systems optimisation
Examensarbete för masterexamen
With the emergence of renewable energies many technical questions about the efficient integration of these in the existing mixes of technology raise. Renewable energies are characterised by environmental savings regarding Green House Gases emissions, and by economic savings corresponding to the running costs linked to fuel purchase, transport or even waste treatment or disposal. The most emergent of them, developed within the last years, is the wind energy. Geotropic wind currents and movements constitute an abundant and free resource in many places. Moreover, wind power generation is non-polluting. Integrate wind turbines in remote areas could be therefore a solution to replace conventional technologies such as fossil fuels combustion. In large mixes, the variability of wind power sources could be carefully controlled with adapted electrical equipment and grid connection. Where there is no central grid it is even harder due to reduced mixes of technology. These mixes are often limited to only one power source in many rural areas of the developing countries, islands and other remote places. The technical feasibility of wind power integration has to be carefully considered as a wish to optimise existing Wind Diesel Systems and also to increase the wind energy penetration in future systems. Existing wind diesel systems show the interest to integrate wind energy but show also the need to design these systems appropriately. Wind turbines output power short time fluctuations are significantly higher than they are for other energy supplies and can perturb the whole system. The diesel engines are able to manage load variations, but not high variations such as sudden decrease of wind without an efficient system of control and regulation. This system of control could be improved by studying the effect of the wind variation on the system behaviour in the aim to regulate further more both combined wind turbines and diesel engines. Study the effect of wind turbulences on Wind Diesel (WD) systems remains on the analysis of the system characteristics such as the penetration of wind power, the quantity of produced power by the diesel engines and the quantity of rejected power. These data can be followed with different time frames according to available data in saving computer system. These time scales are often hourly based for wind resources calculation but could and should be secondly or minutely based for further analyses. Detailed technical analyses about WD systems characteristics show the possibility to increase the wind penetration with a diesel set-up controller efficiently defined. Limiting values to switch off and on the respective gensets have to be determined to ensure that the generators do not switch off too fast. This evolves that one or two engines should run at low partial loads during 25 % of their running time, and this confirms the interest to develop Low Load Diesel. Predict wind diesel systems reaction to short term wind fluctuations is a good approach to find adapted and efficient operation conditions to use as much as possible wind energy and to minimise possible negative effects on diesel generators while ensuring a reliable power quality. Further study directed in this sense about strategies implementation will adequately complete this one which brings the keys to follow the behaviour of WD systems and which allows to determine the limiting constraints to raise the wind penetration in existing reduced mixes of technology. This responds thus to the wish to increase the development of WD systems, particularly where the fuel dependency could or should be reduced.
Elkraftteknik , Medicinska grundvetenskaper , Electric power engineering , Basic Medicine