This paper presents the comparison of synchronization techniques for a photovoltaic system, which injects power to a single-phase electric grid. The single-phase system uses an electronic power inverter with a voltage and current control system, with a Bipolar-PWM modulation. The synchronization techniques try to achieve a power factor close to one for the signals at the output of the inverter, despite the presence of a polluted grid under different conditions as frequency jumps, phase-angle jumps, voltage sags and polluted by the third and fifth harmonic. Finally, the simulation results for the operation of synchronization techniques under the different disturbances of the grid using PSIM software are shown, the results of the comparison are presented and conclusions are drawn.