Research On High Power Density Isolated DC/DC Converter Used In Space Power Supplies

In the aerospace power supplies systems, isolated DC/DC converters are needed insome occasions which possess higher requirements on security module, and the demandon power rate is becoming higher and higher. What’s more, higher power density isrequired in order to reduce the spacecraft launch costs. The main purpose of this paperis to conduct some research on high power density isolated DC/DC converter, and thispaper chooses to study isolated Weinberg topology.The main research contents are described below. First of all, this paper will studythe open loop isolated Weinberg topology, including the analysis of principle and maincircuit parameter design, and set up a hardware experimental platform to learn about theopen isolated Weinberg loop topology characteristics both in buck and boost state, andmake sure that the topology efficiency and open loop stability are satisfied preliminarily.Then, this paper will study topology modeling based on circuit averaging method, andthe small signal model analysis will be helpful for the design of input filter and closedloop compensation network. Finally, this paper will study the isolation closed loopcontrol scheme, namely the study of isolation feedback control scheme. This paper willadopt double closed loop control of voltage and current, and voltage and currentcompensation network will be designed, then perform isolated Weinberg closed-loopcontrol experiments, and the topology performance must meet the design requirements.Some difficulties of the subject and their solutions are described below. Firstly, theinhibition of switch shut-off voltage and improvement of topology efficiency, this paperwill implement transformer optimization and bring in absorb circuit to solve theproblem. Secondly, even though some previous literature analysis the isolated smallsignal model using state space average method, the modeling result calculation is toocomplicated for practical application. This paper will conduct model optimization basedon circuit average method, and it is convenient for filter design and closed loopcompensation design. Thirdly, the isolated Weinberg has bad performance at higherpower rate, only low power closed loop experiment is conducted according to publishedpapers about isolated Weinberg closed-loop study, this paper will solve the problemthrough the study of small signal analysis and optimization of the closed loop controlscheme.