Control of Dual Stator Induction Generator Based Wind Energy Conversion System

The work presents a robust Control scheme for a Dual Stator Induction Generator (DSIG) based Wind Energy Conversion System (WECS). This developed scheme mitigates deviations in torque and flux of the generator that occurs due to imbalance in the currents of the generator. The models developed comprises of a wind turbine system, a six phase SCIG, two – three phase converters for controlling the generator and a three-phase converter that connects the generator with the grid. A back-to-back voltage source converter was utilized for interfacing the DSIG with the grid. The non-linear model predictive control (NMPC) scheme was used for the control. All simulations were carried out in Matlab 2019b. The result obtained for the electromagnetic torque values obtained showed proper tracking of the reference torque, with an average percentage deviation of 17.11%. These minimal deviations were due to the large variations of the wind speed during these periods. While for the direct rotor flux, it was observed that, the flux settles at time 0.7 seconds which is well within the settling time limit. This showed that the developed scheme has properly decoupled the direct rotor flux from the quadratic rotor flux. For the grid side, the DC link voltage obtained has a settling time of 0.8 seconds, with a minimal overshoot.