Design Of Sliding Mode Controller For DC/DC Converter Based DSP

As the development of information technology industry, because of small size, high efficiency, switching mode power supply has more and more extensive applications, at the same time there are increasingly high requirements. Traditional modeling methods and control method have been difficult to meet the requirements of modern switching power supply, the control of the switching supply power based analog circuits limitations has become increasingly evident, digital control switching power supply has become the direction of switching power supply development.This paper describes in detail the DC/DC converter that is the basic converter of switching power supply about commonly method of modeling, as well as domestic and foreign advanced modeling method of the research status. In the course of the study, recognizing that traditional DC/DC converter modeling method have some shortcomings to be overcome some difficult, with the results of research on hybrid systems, DC/DC converter switching linear systems modeling method was proposed which is a solid foundation of the study and application of Sliding Mode Control theory.Based on the theoretical analysis of the DC/DC converter, this paper sums up the strengths and weaknesses of traditional control methods and advanced control algorithms of the DC/DC Converter. According to DC/DC converter is a typical example of variable structure of the system, this paper select Sliding Mode Control theory as a DC/DC converter controller theoretical basis. This paper researches the characteristics of Sliding Mode control theory designs a DC/DC converter Sliding Mode controller based on HM, and establishes the simulation model of DC/DC converter Sliding Mode controller base HM in MATLAB. Despite the imposition the hysteresis band upon the switching relay to suppress the switching frequency, the controller will suffer from significant switching frequency variation when the input voltage and the output load varied. This complicates the design of input and output filters. Moreover, the variation of the switching frequency also deteriorates the regulation properties of the converters. This paper designs the Sliding Mode controller based on PWM, implements the fixed-frequency control of DC/DC converter in MATLAB. It's is a good design to solved the problem. Simulation results show the feasibility of the algorithm.The control algorithm based Sliding Mode control is relatively complex. It's of complexity and high cost to implement it with traditional analog circuit. With the development of single-chip high-performance DSP controller, application of high-performance single-chip DSP in power control will be an important development trend. Digital controller has advantages in debugging, or product updates or upgrades. Taking advantage of DSP, this paper designed a Sliding Mode Controller for DC/DC Converter based DSP. Hardware Experiment results show the feasibility, practicality of the algorithm.