Control of RSC in DFIG based WECS using Cascade Feedback Linearization Controller

This paper presents an independent control of rotor side converter (RSC)) for a doubly fed induction generator (DFIG). A novel cascade feedback linearization (CFL) technique based on non-linear differential geometry is developed for design of RSC, which leads to decoupled currents. Here, the rotor DC link voltage can be regulated with respect to a square transform on its voltage reference and the d-axis current that satisfies conditions for zero dynamics. The controlled RSC has a capability to track DC link voltage reference faster and also attain global stability. All these features are confirmed through time domain simulation on a 15 KW DFIG Wind Energy Conversion System (WECS).