3kW LLC Resonant Type Modularize Communication Power Supply

The power supply with redundancy, which has larger capacity of output, more stability and more extensive application, should be suitable for the diversification of varied load, and minimum cost. It's a challenge to classical concentrated power source, instead, technologies of distributed power source appear and develop, which become a trend of power supply developing now and in future.This paper focuses on a 220V ac input and 42V-58V dc output -modularize power supply, choosing PFC+LLC resonant circuit as main topology. PFC main circuit and controlling IC are discussed firstly, also, giving major parameters' design. Protecting circuit and delay recover circuit are discussed too. Then, operation principle of LLC resonant circuit is introduced, including main characteristic of LLC resonant, major parameters' design, controlling method and controlling IC. After, this paper also discusses current sharing method, especially maximal current sharing and output limited maximal current sharing. Finally, a modularize power supply with 220V ac input and 3kW output power is completed, two compared experiments with different resonant frequency and different layout design have been done. More, two modularize power supplies with same parameters and layout design are completed for parallel operation experiment. The result of experiment showed feasibility and deficiency of modularize power supply design, and possible improving direction.