Abstract: DC-DC converters plays major role in batter operated devices and adjustable speed drives. DC-DC converters may increase or decrease the output voltage. Size, cost and efficiency of the converters are important factors for selection of converters in an application. Single ended primary inductor converter is proposed in this study, for its output voltage control and less space consumption. The SEPIC converter is presented later on three phase diode rectifier for voltage stability. To enhance the DC voltage stability an intelligent fuzzy logic controller named Accelerated fuzzy PI controller is proposed in this study. The quality of the inverter voltage decides the efficiency of the load. In this study, fuzzy gain scheduling is proposed to control the PWM of the inverter. The total organization is analyzed using MATLAB.