The Design Research Of The High Power Density And An Active Clamped Forward DC-DC Converter

With the continuous progress of science and technology, DC-DC converter as a voltage converting circuit, its main function is to change the voltage and voltage stability,after the converted voltage is more stable and reliable, Therefore, it is widely applied to communications, information, electronics, defense and other fields. Power supply module is a special form of DC-DC converter, On the technical side, it is toward the high-frequency, small size, high efficiency direction. Especially,soft switching technology and synchronous rectification technology provides important technical support in the direction of its development, but also the entire field of power plays an important role.In recent years, there is the high power density and high efficiency DC-DC conversion technology, foreign countries have done a lot of research work, this technique is mainly used in the aerospace field, and achieved many results. In this field of our country, there is less supply manufacturers engaged in research, in this case, this article will expand research and design for high power DC conversion technology, this project comes from the school-enterprise cooperation projects, it has a strong engineering background.This paper designed a high power density DC-DC converter, the converter has high power, small size, high efficiency, high reliability and high stability properties, it is mainly used in the aerospace, power supply for the airborne equipment. Firstly, it introduces the classification and characteristics of the power supply module, a detailed overview on the status of the development of domestic and foreign power module; Secondly, according to the parameters of the power supply module design specifications, comparison of various topologies in applications, We chose the active clamp forward circuit which as the main circuit topology of the power supply module, and the secondary with synchronous rectification. Subsequently, the operation principle of the active clamp forward circuit;Once again, the overall design of the circuit, which surrounds the control chip LM5026 respectively for the main circuit power supply module, the control circuit and optocoupler feedback circuit design. In order to achieve high power density, we use the same three modules connected in parallel to each other, they share a control chip LM5026, the purpose is to make it consistent with the frequency to obtain high current and stable voltage output,at the same time, the components are surface mount type packages; Finally, the use of Flo THERM software, which in Flo EDA module for modeling and simulation of the PCB main power devices.On the basis of theoretical analysis and design studies, an input DC28 V, output power430 W, frequency 200 kHz, volume for the whole brick, the conversion efficiency of not less than 87% of the module power supply has been completed. The experimental analysis shows, the performance indicators of the power modules meet the design requirements, and in line with the development trend of the current power supply module. Has a prominentresearch value and practical significance, whether it is from the user needs, or to improve the competitiveness of their products.