The Vector Analysis of Doubly Fed Wind Generator´s Power-angle Characteristic

According to the control principle of the vector analysis, this paper establishes Variable-Speed Constant-Frequency (VSCF) doubly fed induction generator´s power-angle characteristic equation and static synchronizing torque´s mathematical model firstly. The equation directly shows the relationships of DFIG´s power-angle & static synchronizing torque and generator´s parameters & rotor excitation control parameters. The theoretical analysis indicates DFIG´s power-angle characteristic and static synchronizing torque which are multivariate functions are different from round-rotor synchronous machine. Within the rated speed, its power-angle and stability depends on the rotor excitation control technology and control strategy. In this paper, research results lay theoretical foundation of VSCF doubly fed wind generator´s stability and control strategy.