Research On Low Power DC/DC Converter With High Power Density

For the rapid development of telecommunications, power systems and personal digital products, the power supply module is used more widely. As distributed power supply system is applied in the aerospace field, the module power supply is used more widely in the aerospace field. This thesis is devoted to study the low-power high-power density DC/DC power supply module.Firstly, after comparing of several different isolated DC/DC converters, Low-side active clamp forward converter has been selected to be the main circuit topology of the second power supply. And detail operation principle is presented.Secondly, many new technologies such as soft-switch, synchronous rectifier, planar transformer, and magnetic-integration have been used in the converter. After all of that, I made some research for them and make the converter have a better performance. Magnetics is one of the main factors, which limit the power-density and characteristics of power module. For lowing weight and volume, reducing power loss and ripple current, improving efficiency, the magnetic-integration technique has been one of the focuses in the paper.Once again, the operation principle of IM-FAC converter is analyzed, the influence on FAC converter introduced by IM is described and the design rule of IM is presented. And, the IM-FAC converter and DM-FAC converter of 18V~36V input 12V/50W output are completed. The experiment results verify the effectiveness of magnetic-integration technique.At last, the experimental results based on a 50W power supply module with 18~36V input, 12V output and the switching frequency of 500kHz are given to demonstrate the performance characteristics. The volume can be done to 1/4 brick, and efficiency can be up to 86%. The prototype's various property indexes meet the design demands.