A single-phase synchronization technique for grid-connected RESS under distorted grid conditions

The control of single-phase grid-connected Renewable Energy Storage System (RESS) requires a very fast and accurate estimation of grid voltage frequency and phase angle. A Phase-locked Loop (PLL) based synchronization algorithm usually extracts this information. The operation and control of entire system is directly affected by the performance of PLL. In this paper, a novel less complex Advanced Single-phase PLL (ASπPLL) technique has been proposed for the fast and accurate extraction of grid information in a battery storage system under distorted and abnormal grid conditions such as under harmonics, interharmonics, DC-offset and grid faults. The proposed method presents a faster dynamic response, lower frequency overshoot, and accurate estimation under off-nominal grid frequencies. More importantly, its computational complexity is very low. The advanced performance of the proposed ASπPLL is verified through simulation and experimental results.