Wind energy has become the world’s fastest growing energy source，as environmental concerns have focused attention on the generation of... Show moreWind energy has become the world’s fastest growing energy source，as environmental concerns have focused attention on the generation of electricity from clean and renewable sources. New capacity from wind turbines has been growing fast since 2004. Installed capacity reached 196630 Megawatt in 2010 worldwide. 2011 will also see good growth. Reliability and quality of the electrical power supply is of great importance for all grids. A well designed wind-turbine power source can help balancing the unpredictable power changes caused by the Load-side of the grid (Due to the meteorological nature of long-lasting wind at the sea, the offshore wind turbines are more stable in their power production aspect). Alone more and more R&D efforts, PMSG-based direct drive wind turbine generator has become a trend in the industry, its full scale back-to-back converters can achieve fast response of power factor tuning, which directly offers an option of generating a certain amount of reactive supporting power in solving short-term voltage stability problem in the local grid and a desired quantity of active power for mitigating the frequency oscillation in the system. Topics in this thesis includes: (1) analysis of the wind turbine generator model equipped with full scale back-to-back converters and their control schemes are proposed; (2) the low voltage ride-through test of a wind farm with the modeled wind turbine generator integrated into a finite 3-bus system is provided for further short term voltage stability studies; (3) the comparison is rendered between an offshore wind farm with no support on reactive power and the one with automatically reactive power support on voltage drop response in an 8-bus system connected with HVAC submarine cable; (4) study on dynamic active power compensation from wind farm for improving the frequency stability when large disturbance introduced. Keywords: PMSG, full scale converters, reactive power, short term voltage stability, active power, dynamic compensation M.S. in Electrical Engineering, December 2011 Show less
