Impact of PLL Dynamics on Frequency Stability in Low Inertia Trending Power Systems

Due to the higher frequency fluctuation in the low-inertia trading power system, phase converter synchronization with the grid is a critical problem. A phase-locked loop (PLL) is a standard synchronous approach in grid-connected applications that shows robust performance under ideal conditions. However, a second-order generalized integrator (SOGI) filter-based synchronous reference frame PLL (SRF-PLL) is proposed to improve the steady-state stability during unbalanced and distorted grid conditions. The PLL parameters, such as the damping coefficient and natural frequency, are designed in such a way as to increase the PLL's locking time to correct high-frequency variations. The simulation is performed on the Matlab Simulink platform to verify the theoretical analysis. Finally, the whole experiment is implemented on an Industrial grade DSP to support the proposed system's effectiveness.