چكيده به لاتين
Because of numerous problems and constraints related to using fossil fuel sources, renewable energy sources, and improving facilities and technologies in order to extract energy from these sources have gotten double emphasis. However, in recent years solar energy, as one of the cleanest and the most affordable renewable energy sources, has been considered more than ever, there are several problems and obstacles in solar systems which they slow down the pace of development of this technology. Of the most important constraints in this area is low voltage in solar panels output which causes high voltage difference between solar systems and power grid. Of the fundamental solutions to unravel this constraint is using high step-up DC/DC converters in order to enhance the level of required voltage.
On the other hand, scheming support systems to storage generated energy is truly essential because of two reasons; first, generating energy is possible only during day when the sun shines, and second, supplying electric power when breakout occurs in the distribution network. This necessity becomes more important when sensitive loads appear. Consequently, converters which not only can meet the voltage difference, but also have bi-directional power transfer capability, are needed.
Generally, there are some fundamental means, such as using coupled inductor, switched capacitor units, and interleaved structures to increase voltage gain and power level in DC/DC converters. Proposed structures, based on designing priorities, have used one of these methods or a combination of them.
In this research, in addition to study previous presented converters, designing and simulating a new non-isolated, bi-directional converter with great voltage diversity will be proposed.
By considering core and winding losses, simulation results indicate more than 95% efficiency for a 1Kw, 48v-380v prototype, which shows a significant improvement in comparison with resembling structures.
Another benefit of this structure is supplying voltage gain of 8, with the turns ratio equal to 1.5 and 0.75 and 0.4 duty cycle in boost and buck states, respectively.
Keywords: DC/DC converter, bi-directional converter, grid connected photovoltaic systems, non-isolated converter, winding cross-coupled inductor.
