大型风电场的瞬时稳定和模拟论文.doc

大型风电场的瞬时稳定和模拟毕业论文 Modelling and transient stability of large wind farms Vladislav and Hans Knudsen and Arne Hejde Nielsen and Jorgen Kaas Pedersen and Niels Kjolstad Poulsen Departments of Electric Power Engineering,Technical University of Denmark,Building 325,DK—2800 Lyngby,Vladislav Demmark 1.Introduction Denmark has currently about 2300 MW wind power capacity in on-land and few offshore settings, which corresponds to more than 20% of power consumption(in average). Further, construction of two large-scale offshore wind farms of 150 MW power capacity each has been announced. The first large offshore wind farm in Denmark will be constructed at Homs Rev by the year 2002 in the area of the system operator ELTRA .This will be followed by the first in the area of the Eastern Danish system operator ,ELKRAFT System ,large offshore wind farm at Rodsand by the year 2003. The installed capacity in on-land settings and in combined heat-power units(UHP)will increase as well, whilst the power production and control ability of the conventional power plants with respect to voltage and frequency are reduced . In the years to come ,the power production pattern in the Danish power system will change from the power supply from conventional power plants―as it is known today―to a power supply mix, where about 30-40%of power consumption(in average) is covered by wind power. In other words, the power technology will undergo changes from a well-known technology built-up about conventional power plants to a partly unknown technology―wind power. In the year to come it will be focusing on maintaining power system stability and voltage stability, for example at a short circuit fault, ensuring power supply safety and other important tasks as amount of wind power is drastically increasing. This situation makes it necessary to find solutions with respect to maintaining dynamic stability of the power system with large amount of wind power and its reliable operation. These solutions are based on a