Operation control and space vector analysis on doubly fed wind power generator

In order to analyze the electromagnetic nature of AC excitation for doubly fed wind power generator(DFWPG),a method based on space vector theory is applied to set up the space vector model of the DFWPG.According to the space vector model of DFWPG,a whole model of pitch-controlled variable-speed WECS(wind energy conversion system) is set up and the simula-tion curves of different operation conditions are presented.By comparing the phase angle of stator and rotor MMF(Magnetic Motive Force) space vector of DFWPG with AC excitation or without AC excitation,the effect of the rotor AC excitation at changing the rotor MMF is revealed.The re-search results show that when the DFWPG is running at sub-synchronous mode,the phase of rotor MMF space vector can advance with respect to that of the stator MMF space vector by regulating the AC excitation current.Thus the DFWPG can still supply power to the grid.