Built-in Input Filter DC/DC Converter Used In The Application Of Photovoltaic Power Gencration

With the progress of technology and the continuous improvement of people’s living standard, People’s demand on the traditional energy is growing, causing the shortage of the traditional energy, and the Environmental pollution is also increasingly heavier. To replace the existing coal, oil, and other non-renewable energy which has dropped, the rise of new energy technology has already become the international energy strategy mainstream. Among all the new energy, solar energy has been gaining more and more attention in many application areas because of its advantages of no pollution, sustainability, wide distribution and variety of application forms. Therefore, a number of DC/DC converters with high performance used in photovoltaic power generation occasions have been addressed in recent literatures. The converters which are isolated versions of the Buck converter are the most widely used configurations. However, a large input filter is still needed in these Buck derived converters to alleviate the noise problems caused by the pulsating input current, which not only disturb the operation of nearby digital and communication equipment, but also seriously affects the stability and the sever life of the solar cells.A design of built-in input filter in isolated converters which are derived from Buck converter is proposed in this dissertation. The built-in input filter, consisted by the transformer leakage inductance and cross-coupled capacitors, can effectively realize the non-pulsating input current without the help from extra input filter. Based on this design, the forward converter and the full-bridge converter with built-in input filter are proposed, the detail operations of the two converters are also analyzed in this dissertation with the help of the PSIM software. On the basis of the above, this dissertation summarized the general principle of all the converters with built-in input filter which have been designed and finally, with the help of this principle, a new half-bridge converter with built-in input filter is designed in this dissertation. The circuit operation is also analyzed by using PSIM software.Based on the simulation results, the design guideline is provided and a100kHz,400W converter principle prototype is built for performance evaluation. The results show the rationality of the circuit design and the effectiveness of non-pulsting input current ability.