Grid Synchronization of Distributed Generation based on MROGI-FLL with Universal Active Power Filter

This paper proposes a new frequency locked loop (FLL) based on modified reduced order generalized integrator (MROGI) to extract positive and negative sequence components (PNSC) and phase angle for distorted grid conditions. The proposed MROGI-FLL is used in the synchronous reference frame (SRF) technique to control the universal active power filter effectively. The proposed method has fewer computations and good accuracy to extract the fundamental positive sequence component of distorted load conditions. Along with mitigation of power quality issues, the distributed generation (DG) are integrated at the DC bus to provide active power to the system, thereby reducing demand on the supply system. The proposed system improves the reliability and quality of power supply to the distribution system at less cost. To validate the performance of the proposed system, simulated in MATLAB and verified prototype in the scaled-down laboratory under verity of disturbances such as voltage sag/swell, load distortion and change in DG power.