Nonlinear Adaptive Partial Feedback Linearizing Controller Design for Permanent Magnet Synchronous Generator-Based Wind Farms

A nonlinear adaptive partial feedback linearizing control scheme is proposed in this work to design switching control actions for the machine-side converter (MSC) and gridside converter (GSC) in a permanent magnet synchronous generator (PMSG)-based wind energy conversion system (WECS). The main control objective is to ensure the low voltage fault ride through (LVRT) operations of grid-connected PMSGbased WECSs when there are grid faults. In the proposed scheme, the combination of the partial feedback linearization and adaptive backstepping scheme is employed where the first approach is used to linearized the PMSG-based wind farms by canceling nonlinearities and parameters appearing within the partial feedback linearized model is adapted through the later scheme. In this way, the proposed control scheme guarantees to ensure the LVRT operations under any operating condition and maintains robust performance with variations in parameters. In the proposed scheme, the stator flux is also embedded with unknown parameters in order to avoid the estimation of this flux. The switching control actions (for both MSC and GSC) and parameter adaptations laws are designed in such a way that the overall stability of the PMSG-based wind farm is ensured under any circumstance. A grid-connected PMSG-based wind farm is used to evaluate the performance of the proposed adaptive partial feedback linearizing controller (APFBLC) through simulation results and compared with an existing partial feedback linearizing controller (PFBLC).