Control and power transfer operation of WRIG‐based WECS in a hybrid AC/DC microgrid

Abstract

In this study, the control and power transfer operation of wound rotor induction generator (WRIG)-based wind energy conversion system (WECS) in a hybrid AC/DC microgrid (DCM), delivering power during islanded and utility-tied conditions are dealt. The system encompasses WRIG, rotor-side converter (RSC) and stator SC (SSC) connected back–back with DCM. AC loads, AC end of SSC, stator of WRIG and a switchable utility frames the AC microgrid. During islanded mode, stator voltage and frequency are regulated with proportional–integral (PI) controllers through RSC. During utility-tied mode, RSC is currently controlled to perform bidirectional slip power transfer. Load compensation is achieved by current-controlled SSC at all conditions. Instantaneous power theory is employed in the current control of RSC and SSC for generating reference currents. On the basis of wind/load conditions, all possible operational modes are formulated. The power transfer operation during occasional conditions such as shorted winding, over loading, low wind, machine stall and no load claims the merit of the setup. A supervisory control algorithm is developed for executing smooth power transfer. The dynamic operation is experimentally analysed to confirm the efficacious working of the WECS.