Control Technology, Based On The Number Of Synchronous Buck Converter

Along with the developing of information technology, the speed of CPU is faster and faster. At the same time the quality requirements for power supply are becoming stricter and stricter, for one hand the output voltage should be as low as possible, for the other hand the output current should be very large. In this condition, the efficiency of power supply is the key problem. As an important DC/DC cutting topology, Synchronous Buck composed with the advantages of synchronous rectification technology can improve the efficiency greatly, so it is widely used in the low voltage and large current condition.Synchronous Buck switching regulating system as a high-order, discrete, nonlinear, sick system, is difficult to establish accurate model, so the choice of its control technologies and the design of its control circuit should comprehensively consider many factors. By the precondition of meeting the designed performance indexes of convertor, should comprehensively consider the system's reliability of operating, the simplicity of debugging and the rationality of cost. The paper analyzes the control technologies used on synchronous buck convertor, summarizes which advantages and disadvantages and discusses the different application situation. So it's useful for the choice of control technologies of synchronous buck convertor.The conventional control strategy is based on the analysis of low frequency signal, so the used control technology in large signal condition may be unsteady. Along with the developing of control theory some nonlinear control technologies are trying to be used on the switching convertor because of their special performance.This paper deduces and realizes a nonlinear control strategy-capacitor charge balance strategy, although this strategy is deduced on the synchronous buck convertor which can be used on other kinds of switching convertor.In order to realize the digital control of synchronous buck convertor and verify the correctness of the deduced capacitor charge balance strategy, the paper designs and builds a digital control system using the TMS320F28335 as the core of control, and finishes the experiments under the guidance of MATLAB/SIMULINK simulation results. Simulation and experiment results prove that the control effect of capacitor charge balance strategy is better than the conventional strategy and this matches the design expectation.