Position Sensor-Less SRG Variable Speed WECS and an SECS-Based Microgrid Under Nonideal Grid and Load Conditions

This article presents a microgrid (MG) comprised of a switched reluctance generator (SRG)-based wind energy conversion system and a two-stage solar energy conversion system that operates satisfactorily at nonideal grid and load conditions. A sliding mode observer is implemented to estimate the rotor position and speed needed for SRG operation. Load compensation capabilities are achieved using a robust least mean logarithmic square adaptive filter. In contrast to currently available adaptive filters, this method demonstrates improved performance in estimating active fundamental weight components from distorted or unbalanced load currents. Specifically, it exhibits reduced weight oscillations and achieves a quicker convergence rate. In addition to load compensations, the proposed MG provides multifunctionalities, such as polluted grid mitigations, satisfactory operations in grid-tied mode and islanded mode, and seamless transitions between these modes. A dual third-order generalized integrator frequency-locked loop with a dc-loop filter is implemented to achieve polluted grid mitigations and seamless transition capabilities. It accurately estimates grid voltage phase angle and positive sequence components, even at nonideal grid conditions.