High-Order Generalized Integrator ESO-Based PLL Considering Time-Varying Disturbances

Phase-locked loop (PLL) is essential for grid-tied applications. Generalized integrator (GI) extended state observer-based PLL (GIESO-PLL) stands out among disturbance observer-based PLLs due to the excellent periodic disturbance rejection capability. However, the system dynamic response is deteriorated by employing GI units. To this end, a high-order GIESO-based PLL is proposed to consider various grid time-varying disturbances. Theoretical analysis and experimental results proved that the proposed PLL achieves good dynamic performance and strong disturbance rejection capability.