Efficient Modeling and Systematic Design of Enhanced Phase-Locked Loop Structures

This article presents approaches for efficient modeling and systematic design of enhanced phase-locked loop (ePLL) structures. While different ePLL structures have found a wide acceptance for various applications, their modeling and design aspects have not been fully and systematically reported in the existing literature. This article fills this gap by presenting an effective modeling approach for both the single- and three-phase ePLLs. The models are derived with a view to minimize the number of parameters to be adjusted to simplify the design. The models are then used to develop systematic design algorithms for their parameters. As an example, application of the ePLL in a grid-connected inverter is formulated and studied through simulation and experimental results. The design and simulation files are made available.