Study On The Technology Of Variable-Speed Constant-Frequency Wind Power Generation

Now, energy souces consume increasing daily and environment empoison being serious gradually, wind power, as renewable, no pollution energy source, is paid great attention by more and more countries. The technology also become research hotspot of many country's scholar.The paper has done all-around study on the AC excited of variable-speed constant-frequency (vscf) wind power generation. The author has done thorough study on the vscf wind power generation technology using wound-rotor doubly-fed induction generator, from simulation to experiment, from theory to practice. He also did at large theory analysis to the vscf wind power generation technology using cascaded brushless doubly-fed generator, and has established stability theoretical foundation for continue study work.The paper has analyzed the mathematic model of the AC excited doubly-fed machine and the stator flux oriented vector control strategy of the motor as vscf wind power generator firstly. Secondly, it has put forward and designed the dual PWM converter with the capacity of energy flowing bidirectional aimed at the demand of rotor energy bidirectional flow. Then it brought forward the method of emulating wind turbine by DC motor to solve the prime motor issue for the study of wind power generating system in lab. It also has established the simulation flat of the AC excited vscf wind power generation stator flux oriented vector control system and done the simulation work of the adjusting alone of the active and reactive power. The author constructed reliable and integrated experimental system and did a series of experimental study including no load and connecting to grid conditions. The result of the simulation and experiment all validated the validity and feasibility of theoretical model and control strategy.The author firstly analyzed the mathematic model of the cascaded brushless doubly-fed machine (cbdfm) on the dq and MT coordinate rotating at rotor speed and synchronous speed seperatly, and the equivalent circuit of steady state. The author also analyzed the stator power winding flux oriented vector control strategy of the cbdfm as vscf wind power generator and validated the validity of the model and strategy by the simulation analysis.