Research On High-power All-digital Switching Power Supply System Based On DSP

With the development and progress of science and technology, the power system has also ushered in the peak of development. Currently, the market communication power supply, UPS and so has gradually become mature, but the stand-alone powers are small, generally a few hundred watts to several kilowatts, to require larger power occasions, stand-alone can not meet. The work mode of multiple parallel will bring the current imbalance. Therefore, the design of a stable, high precision, and larger stand-alone power switching power supply, is the focus of this study.Analog switching power supply device aging, temperature drift and scalability poor, can not achieve multi-machine work together, is not conducive to the development of distributed power topology. In response to these problems, this paper proposes a DSP stand-alone power20KW based all-digital switching power supply design.First, according to the specific power supply design parameters, the study of the characteristics of the type of the main circuit topology, power applicable range of the selected structure of the main circuit of the DC/DC, and the corresponding device parameter calculation and selection. In order to meet the power dynamic and static performance, fast operating speed DSP as the core controller. In order to reduce losses and voltage spikes, the paper combines phase-shifted full-bridge soft switching PWM mode with switching tube to achieve the purpose of improving the overall efficiency of the power system. Phase-shifted full-bridge super forearm and lagging leg to achieve soft switching process, analyze the difference between the two leg achieve soft switching process, and propose solutions. Research resonant inductor the lagging arm ZVS and duty cycle lost phenomena, given solutions.Secondly, through the power system of the approximate transfer function for power system nonlinearities and uncertainties, fuzzy PID algorithm using three parameters online self-tuning PID fuzzy control, output voltage and output current of the power supply system closed-loop full digital control. The paper deeply studies the implementation process of the fuzzy PID controller. The use of Matlab simulation results show that the fuzzy PID controller in the power system than traditional PID controller has the advantages of small overshoot, and fast adjustment.Finally, in-depth study TMS320F28335phase-shifted full-bridge soft switching PWM drive signal modules including controller ePWM introduction, register introduced and the implementation code. By oscilloscope verified driving waveforms of the phase-shifted full-bridge super forearm and lagging leg and gives the main flowchart of the software programming.