Robustness evaluation of phase-locked loop algorithms for single-phase distributed generation systems

In grid-connected application of distributed generation sets, accurate estimation of the phase of the grid voltage is a fundamental task for developing reliable control algorithms, especially in single-phase systems. Many algorithms have been proposed for estimation of the phase of the voltage grid based on Phased-Locked Loop (PLL) techniques. In this paper, in order to evaluate the performance in terms of noise rejection and dynamic response of most used PLL algorithms, a comparison accomplished through simulations and experimental results is presented in different operating conditions and voltage disturbance. The analysis conducted in the paper is synthesized in a table useful to choose the appropriate PLL structure at the design stage.