Investigation of phase locked loops in microinverters for varying grid conditions

Efficient conversion of the PV energy requires better hardware and software solutions. Apart from efficient power structures, microinverters should have control algorithms like maxinmm power tracking and phase locked loop (PLL). In this study, an overview of push-pull based microinverter and its control structure is presented. PLL structure is given with a mathematical background and it is simulated for different cases using MATLAB. PLL algorithms are implemented in a microcontroller and they compared with experimental results. Experimental results are in agreement with the simulation results.