A three port DC-DC converter integrating PV systems for high step up applications and also for power supply design with high efficiency and maintain voltage stability. This paper describes the non-isolated high step-up DC-DC converter using Zero Voltage Switching (ZVS) Bi-directional Integration Technique (BIT). Integrated multi-port converters for interfacing several power sources and storage devices are widely used in recent years. Instead of using individual power electronic converters for each of the energy sources, multiport converters have the advantages including less components, lower cost, more compact size, and better dynamic performance. In many cases, at least one energy storage device should be incorporated. For example, in the electric vehicle application, the regenerative energy occurs during acceleration or start-up. Therefore, it is very important for the port connected to the energy storage to allow bidirectional powerlow.