Research on Real Time Active Power Characteristics of DFIG Rotor under Changes of Slip.

When wind speed changes, the slip of Doubly-Fed Induction Generator (DFIG) changes first, then it causes changes to the state of the DFIG. When the DFIG runs on hyper-synchronous power generating state, rotor and stator generate active power to outside. When the DFIG runs on sub-synchronous power generating state, the rotor absorbs active power and stator generates active power to outside. When the real-time requirement is high, the process needs to be calculated in real time. This paper uses the real time calculation formula about slip, stator current vector and rotor active power to analyze change laws of rotor active power under changes of slip. The results show that the formula can calculate the active power of rotor in real time, and with increasing of slip, the active power absorbed by DFIG rotor gradually decreases, the active power generated by DFIG rotor gradually increases. [ABSTRACT FROM AUTHOR]