Abstarct: In this thesis, the connection of power electronic converters to the grid and control of single-phase PWM rectifier have been investigated. After carefully reviewing the overall structure and behavior of PLL and introducing its various types, a suitable structure for synchronizing the single-phase rectifier is proposed. The desired performance of single-phase PWM rectifiers depends on the coherence of the current and the input voltage with a low THD, while the output voltage has a limited fluctuation amplitude. Various structures for single-phase rectifiers have been introduced. In this thesis, the main structure with four power keys has been investigated, and it has been simulated after designing and providing a suitable controller for achieving the desired goals with the proposed PLL. The cascade control has been used for controlling the system. It consists of two nesting loop. The inner loop controls the input current with slip mode control, and the external loop controls the output voltage using the PI controller. In order to verify the accuracy of the simulated results, a 100 VA laboratory prototype was used and simulation and experimental results were compared. The simulation and prototype results show that, the input current has a low THD and is acceptable. The PF of the converter is very close to unit. Also, the voltage controller stabilizes the output voltage with the least oscillation at the desired voltage level.