Differential geometric control of grid interfaced permanent magnet synchronous generator (PMSG) under symmetrical grid faults

The Variable speed wind turbine generators, such as (a) PMSG and (b) Doubly Fed Induction Generator are widely employed in Wind Energy Conversion System (WECS) having capability of better exploitation of available wind energy using partially and full-scale Power Electronics Converters (PEC). Compared to DFIG, PMSG is preferentially employed in WECS due to some pertinent features, such as (a) reduced mechanical cost due to simpler mechanical assembly having no gearbox and slip rings, (b) preferred small size, (c) absence of excitation field, (d) presence of magnetic rotor, and (e) fully decoupled connection with grid. However, the interfacing of PMSG with Grid poses some serious issues, namely (a) meeting of stringent grid codes, (b) DC-link voltage stabilization, (c) control system issues, (d) injective of reactive current upon fault, and (e) fault-ride-through (FRT) capability. Therefore, we proposed an advance nonlinear controller based on differential geometry called Exact Feedback Linearization (EFL) to tackle the aforementioned issues and ensure a reliable and sustainable operation under symmetrical transmission line faults. To check the linearity of systems, state feedback linearization conditions are illustrated. Moreover, an FRT scheme namely STFCL is incorporated that will enhance the stability of PMSG-WECS. Simulation of PMSG-WECS is performed using MATLAB/Simulink. Comparative analysis and Performance evaluation of EFL with a conventional PI controller is included to validate and verify the efficacy of proposed control scheme.