Phase Locked Loop for Single Phase Grid Synchronization

Abstract

There are different techniques for synchronized power feeding from the generator to the grid. Phase Locked Loop(PLL) is most efficient and stable for the same purpose. This work is mainly aimed at analyzing phase locking techniques and comparing the performance through the simulator. In this paper, three different methods of PLL are simulated using MATLAB/Simulink. In Power PLL(pPLL) for phase detection, multiplication is done between input-output signal. The drawback of phase lock error of pPLL is overcome by using Quadrature Signal Generator(Qsg)based PLL. In Derivative Element PLL(DE-PLL), quadrature signal for phase detection is generated using Derivative Element. In Adaptive Transfer Delay PLL (ATD-PLL) the phase error due to fixed T/4 delay is compensated by introducing phase error in a feedback loop. Mathematical analysis is done for all PLL technique to obtain controller parameters. PLLs are simulated employing these parameters. Finally, the performance of all techniques is evaluated for simulation results.