Modeling of Doubly-Fed Induction Generator with strong slot harmonic

Abstract

This paper presents a general model of the Doubly-Fed Induction Generator (DFIG). The model includes the influence of slotting on the harmonics of stator- and rotor currents. Most squirrel-cage induction machines can be described well based on a fundamental-wave model of winding distribution. In case of DFIG the slotting and the non-ideal structure of the windings in stator and rotor cause considerable harmonics of stator currents and rotor currents. These harmonics strongly depend on the speed of the machine and present a challenge to model-based control of DFIG. Including the slotting into the model improves accuracy considerably. The model is verified by measurements at a 200-kW DFIG.