Study On The Power Factor Correction Technology For Communication Power Supply

Along with the communication domain rapid development, also day by day increases to the communication facility power supply. Power supply to the quality requirements have become more sophisticated. The traditional correspondence switching power supply input is the diode rectification and the filter capacity combination circuit, the input current wave presents pulse shape, and leads to the power factor on ac line side is very low. Therefore, carrying out power factor correction on the communication switch power has important practical significance , which not only is helpful in saves the energy, but also is advantageous to the communications system overall performance enhancement.In this thesis, the main circuit topology structure has been adopt to Boost type power factor correction with flyback converter , development of high power factor communication power. Through the PWM control strategy, which has overcome the traditional rectification filter circuit harmonic content big and the power factor low shortcoming, can realize the multi-channel outputs, satisfies the correspondence power source load the multiple request, meanwhile can realize the input and output electricity isolation, reduces the disturbance of the input and output.This thesis first detailed analysis of communication power PFC basic principle .By comparing several different PFC converter topology of the advantages and disadvantages. select the best topology which appropriates communication power supply PFC. Then, with poor power factor causes of communication power supply ,Boost type power factor correction of principle, communication power load diversity, further identified Boost power factor correction for the best control strategy and totality design plan.This thesis introduces the average current-mode power factor correction chip UC3854A/B internal structure, function which made in Texas Instruments Corporation of the United States. According to the main circuit characteristics and requirements, using UC3854A/B as the main component of the control circuit. Design a specific, practical multi-output switching power supply in the communication field, which has the PFC function, has given specific design steps and the main parameters of the circuit.Finally, the thesis had the circuit with PFC and the circuit without PFC to make the MATLAB simulation, and obtained the simulation result. By comparing and analyzing further showed that the thesis referred to the PFC circuit to achieve ac line side sinusoidal current control, and to achieve the input current and input voltage with the same phase, so as to achieve high power factor rectifier performance requirements, meanwhile could realize the stable output.