Nowadays, interconnecting grid with renewable energy source (RES) is developed to increase power and reability of the system. However, the integration between RESs with grid must be synchronized so that the system can work. In this paper, natural reference frame was used to synchronize hybrid systems of RESs with grids. The DC voltage generated by Photovoltaic (PV) and Wind Turbine will be converted into 3 phase voltages by the inverter. The Pulse Witdh Modulation (PWM) on the inverter that has been regulated by current control and Phase Locked Loop (PLL) makes RESs interconnect with grid. Simulation is designed using Power Simulator software (PSIM) and tested with various conditions. The simulation results show that the renewable energy source system connected to grid has synchronized and work well.