Calculation of Equivalent Circuit Parameters of Doubly Fed Induction Generator Based on Magnetic Field Finite Element Analysis

Equivalent circuit parameters of doubly fed induction generator (DFIG) play an important role in the estimation of steady state and dynamic performance of wind turbine system. A new method based on magnetic field finite element analysis is proposed to improve the calculation of the DFIG parameters, especially the inductances. The magnetic field excited by the stator or rotor current is exactly divided into main flux field and leakage flux field via using a fictional current sheet distributed sinusoidally along air gap, which generates the same fundamental waveform flux in the air gap as winding currents. The method calculates the field inductance and the combination of slot leakage inductance and harmonies inductance by 2D static finite element analysis, while the end leakage inductance by approximated analytical formula.