Stability of DFIG stator voltage oriented control design based on internal model control

This paper presents the stability investigation of Internal Model Control (IMC) based control design of doubly-fed induction generator (DFIG) in Stator-Voltage-oriented (SVO) synchronous reference frame. The state-space model of DFIG including inner current closed loop dynamics with different feedforward compensation schemes is developed. The inner current loop dynamics is usually ignored when SVO control is employed. The effect of inner current loop dynamics on the damping of critical poles of the system is illustrated through analysis and simulation. The analysis makes it clear that the stability of DFIG in SVO depends mainly on the tuning of the proportionalintegral (PI) controllers. Erroneous tuning results into instability. This paper contributes the tuning methodology of the PI-controllers in order to secure the stability of DFIG under SVO vector control scheme.