Abstract
This paper deals with the simulation model of synchronous rotating reference frame and trigonometric phase lock loop (PLL). For grid-connected inverters, a synchronization control technique is required for maintaining high power quality and efficiency of the system. There are many phase lock loop algorithms used for synchronization like enhanced PLL, power PLL, quadrature-based PLL. This paper presents two phase lock loops for utility grid-connected inverters. The circuits are simulated using PSIM simulation package, the generated phase angle of the PLL as its output is converted into a sine wave by adding a sine block, and results have been analyzed and discussed by the suitable input and output waveforms.