Reza Hemmati

This paper presents a novel control scheme in doubly-fed induction generators (DFIG) wind turbine for operation under time-varying unbalanced loads. The proposed control scheme is implemented on a DFIG connected to the external grid. Additional equipment such as battery, thyristor-controlled reactor (TCR) and thyristor-switched capacitor (TSC) are integrated to the DFIG. These devices are integrated to DC link, grid side and rotor side converters. The developed control scheme aims to achieve several purposes simultaneously including voltage compensation, damping fluctuations, regulating frequency, increasing resilience, and balancing the unbalanced time-varying loads. Each purpose is realized by designing a separated control loop on DFIG, battery and TCR-TSC. All the designated control loops are operated coordinately. The non-linear time-domain modelling and simulations are carried out in MATLAB software and demonstrate that the proposed multi-purpose control plan can optimally utilize set of DFIG/battery/TCR/TSC and achieve all the objectives efficiently.