The Design Of 270W Fan Station Switching Power Supply

Currently,mobile communications have become an important component of life and work. Communication equipment which power is from the fan station Power is usually scattered layout. The performance of the fan station Power affects the performance of communication systems.Efficiency, reliability and clean are requirements of the communications system and the development direction of the fan station Power.A design proposal about 270W power supply module with clean and improving the reliability for the target is put forward in the paper. The paper shows that Power Factor Correction(PFC), two transistor forward converter and modules current sharing solutions, the main research work carried out as follows:To reduce pollution of the power, the former AC/DC Converter use Active Power Factor Correction(APFC). The design of the former circuit of APFC based on the average current control method.A detailed analysis of the circuit theory, circuit components parameters and energy storage inductor of Boost converter are all calculated, and make its modes and simulation, experiment is ideal to achieve the desired results.DC/DC circuit of the single module applys two transistor forward converter topology, which the switch voltage stress is low, the advantages of anti-through of the bridge, so it has high reliability. The paper presents the design of main circuit and control system of two transistor forward converter, and Carries out the selection of magnetic components that were more in-depth researched, that is the design of a high frequency transformer and inductors. Using peak current mode PWM controller UC2845 in control circuit, analyzing the function of feedback compensator to increase,then, the reasonable of design is proved by simulation.Multiple modules current sharing can make use of N +1 structure, reducing system redundancy and improving its reliability.To improve station power system reliability,some current sharing methods about the power modules are resear- ched.Then, it selects the UC3902 based on the maximum current sharing method and builds its the external circuit. Both of the same 270W switching power supply current sharing is simulated in PSIM.Finally,the results prove the validity of the theoretical analysis and the circuit board is still on commissioning.