Comparative Study of Control Methodologies and PLL Topologies to Enhance the Performance of the Synchronization of Grid-Tied PV System

The usage of photovoltaic systems connected to the electrical grid requires that the output voltage be synchronized in amplitude, phase, and frequency with the power grid. Then, the Phase-Locked Loop (PLL) is the system responsible for this synchronization. However, the quality and performance of the PV system output signal depend on tuning methods of the low pass filter as well as the PLL topologies. In this paper, four PLL topologies are compared such as Synchronous Reference Frame (SRF-PLL), Second-Order Generalized Integrator PLL (SOGI- PLL), Enhanced PLL (EPLL) and Quadrature PLL (QPLL) and tuned methodologies such as Ziegler-Nichols (ZN), CHR and ITAE method are investigated. Several tests were carried out to assess the performance of each PLL methodology together with each tuning control method. Also, the harmonic rejection capacity for each PLL architectures was evaluated. After all the simulated tests, the ZN method combined with the SOGI-PLL topology shows the best results compared to the other approaches.