Design & Development Of Intelligent Communication Switching Power Supply Based On DSP

High frequency switch mode power supply, which has the advantages of light, high efficiency and small output voltage ripple, now has been applied step by step in the new type power system of modern communication devices. This thesis focuses on the full digital control which is based on digital signal process (DSP). A communication switch mode power supply (SMPS) with the output 48V/50A has been designed. By using the small signal mode, we have built the two circle loops which contain the voltage loop and the current loop in order to generate the digital pulse-width modulation (DPWM). The full digital control system could overcome these disadvantages that analog system has.During the research, transform efficiency of the power supply have been increased by using soft switching technology. And the structure of full-bridge phase-shift control zero-voltage switching pulse-width modulation (FB-PS-ZVS PWM) has been adopted as the main transition circuit of power supply. Combined with the current methods, a new solution, including adding the resonant inductance to the primary side of the transformer and assistant-resonant network, has been put forward to making up the duty circle lost of the transformer's second side. The operate principle has been introduced.According to the design-process of high-frequent switch mode power supply, this thesis has introduced the selection of the main elements. The main circuit has been optimized by using PSpice. A new method, which is making full use of the DSP's source, has been proposed to produce the digital phase-shift pulse. The thesis has built the small signal mode of the full-bridge phase-shift converter and its transfer function. Meanwhile, the power factor correct circuit (APFC) has also been discussed, especially on two-stage active power factor correction circuit. The results of simulation analysis have been proposed, which is based on Matlab/Simulink. And the sample circuits of input voltage, input current and output voltage of the APFC have also been built.The power supply has the parameters listed as below:Output voltage: 48V, output power: 2400W, switching frequency: 100KHz, ripple modulus: within 0.2%, efficiency: higher than 88%, power factor: higher than 0.99.