Comparative study between the improved schemes of MAF-based robust PLLs

Phase-Looked loop (PLL) is nowadays the best suited technique to achieve grid synchronization. The Moving Average Filter (MAF) based PLLs have received in recent three years considerable attention owing to their attractive features. Indeed, they are able to completely eliminate the unwanted effect of harmonics, dc offset, and unbalanced voltages. Unfortunately, these advantages are paid in term of open-loop bandwidth reduction which worsens the system´s dynamic response. To overcome this limitation, a variety of improved MAF-PLLs schemes were developed to improve the dynamic response. The main objective of this paper is therefore to perform an assessment and a comparative study between the performances these new improved PLL schemes. The proposed study is based on numerical simulation carried out for five cases of grid disturbances.