| There are good prospects for a.c. excited generators (ACEG) in wind-energy generation of variable speed constant frequency (VSCF), whose performances are superior to those of conventional synchronous generators and induction generators.In this thesis, the operation and control principle of a wind-turbine and ACEG based on dynamic synchronous reference frame are analyzed. Based on studies for the operation and speed-regulating characteristics of wind-turbine and relationships among output power of wind-turbine and rotational speed as well as wind speed, a novel excitation control strategy of ACEG for wind-energy generation is presented according to the excitation control model of active and reactive power and speed of ACEG in dynamic synchronous reference frame. Through the analysis for relationships among the voltage at the terminals of stator and output active and reactive power of ACEG in synchronous reference frame, the academic reference for ACEG system of adjusting voltage in wind-energy generation is provided. The general templates of wind-turbine, ACEG, excitation control system and excitation main loop which adopted AC-DC-AC voltage source inverter are established by the Saber simulator. The simulation model of ACEG system for wind-energy generation is composed. With established the model, the steady state and transient characteristics of ACEG system in wind-energy generation are simulated. The influences of excitation parameters on steady state and transient performance are studied. Through simulation for steady state of ACEG system in wind-energy generation, the independent regulating of active and reactive power and speed can be realized, and has excellent dynamic response for ACEG excited by AC-DC-AC voltage source inverter, which is introducing the dual-passage excitation control system in dynamic synchronous reference frame.The studies in this thesis will provide academic reference for the design of ACEG system in wind-energy generation.
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