Fixed-Frequency MCCF Based Grid Synchronization Technique

Synchronous reference frame phase-locked loop (SRF-PLL) is widely adopted for estimating the grid voltage parameters. A good dynamic performance of SRF-PLL can be achieved under ideal grid conditions. However, its performance devolves in the presence of harmonics and fundamental negative-sequence (FNS) component. To address this issue, two module (TM) fixed frequency multiple complex coefficient filter (FF-MCCF) which acts as a prefilter. The frequency adaptive MCCF structure increases the overall dynamic response of the PLL. Further, under off-nominal frequency condition, TM-FFMCCF output introduces error in the estimated phase and amplitude. However, estimated frequency will not suffer any error in estimation. The error compensation in the estimated phase and amplitude is done by developing an error correction criteria. The implementation of proposed scheme is through with MAT-LAB/Simulink environment. Various test cases are considered and results are presented.