The Research Of Digital Average Current Automatic Current-sharing Technology In Parallel Switching Power Supply System

In the rapid development of science and technology today, the demand for the power supply system is increasingly high, especially for large capacity, high security and uninterruptible power supply. If only one power supply can not meet the requirements or malfunction, it would easily cause the entire power system low efficiency or even collapse. So in actual the original centralized power supply is changed for distributed power system, which uses a plurality of power supply modules operating in parallel. The multi module parallel realization of power supply system is the development direction of the current power supply technology. In order to meet the need of different power load, high power switching power supply system changes the quantity of parallel modules, while takes the current measure to ensure each module carrying the same load. So each module bears small electrical stress, and the power system can obtain high efficiency and fast dynamic response. Parallel current-sharing technique can well meet the requirements of power supply in weight, volume, performance, efficiency, reliability and so on.The paper designs a24KW switching power supply, using10+2program. It uses the10main power switch module as12V/200A power. In order to improve the stability,2redundant modules are added. The paper adopts full-bridge circuit to design a sub module of a large power switch power supply. And by DSP chip to realize the digital flow equalizing system is designed. The paper analyzes the working principle and current-sharing strategy, gives the circuit parameters and analyzes the simulation.The paper designs the power factor correction section of the power module, then based on the full bridge converter designs the main circuit part, followed by DSP chip designs flow system, and discusses in detail the average automatic current. It adopts three loop control method, using digital method to realize the switch power supply parallel current equalization. So power supply module gets parallel function to realize higher power supply system. In the last the parallel power system is built on the platform of the MATLAB software, flow effect is verified by simulating.