Hybrid power system is a recent growing technology in the renewable energy sources which has potential to provide high quality of power with maximum efficiency. Photovoltaic system is widely used because it is noiseless, pollution-free and less maintenance. It depends on sun irradiation level, ambient temperature, and an unpredictable shadow. Wind energy is a domestic, renewable source which converts the kinetic energy of the wind motion to mechanical energy by wind turbine. Mechanical energy is transferred to the generator through shaft and generates power. Batteries are usually taken as storage mechanisms for smoothing output power, improving start up transitions and dynamic characteristics, and enhancing the peak power capacity. Combining such energy sources introduces a PV/wind/battery hybrid power system. The converter used for this type of applications is divided into single input converters, two input converters and multiple-input converters. A three input converter are cost reduction, compactness, more expandability and greater manageability.