The Development Of Special Power Supply And Application Research Of Control Algorithm Based On FPGA

As the progress of the social and the development of science and technology, the digital control technology has been widely used in switching power supply. The stability, the reliability and intelligence of switching power supply has also been improved by digital control. Recently, the microcontroller, the digital signal processing (DSP) and the field-programmable gate array (FPGA) are commonly used as the main control chip of switching power supply. With the advantages of the processing speed and the good ability of anti-interference due to the parallel processing, FPGA has become the major control chip in switching power supply. In recent years, the generalized predictive PID control combines the advantages of the simple principle, the good robustness of PID algorithm with the advantage of the good adaptabilities for the modeling error and external environmental interference of generalized predictive control algorithm is widely used, except for the control field of switching power supply.To use the advantages and characteristics of the digital control and FPGA as well as to meet the application demand of related research field, a kind of special power supply with the functions of constant voltage and constant current and PC control is developed, and the generalized predictive PID control algorithm is used as the closed-loop control way for the special power supply. During the development of the special power supply, the analysis of the theoretical knowledge, the verification of simulation, the test of hardware experiment are used as the research methods. The main contents are as follows:1. Combined with the design requirements and the advantages and disadvantages of the commonly used switching power supply topologies, the hardware system of the special power supply in this thesis is identified.2. Combined with the design parameters of the special power supply and the Pspice simulation software, the three hardware circuit parts including the input, the inverter, the output of the main circuit and the FPGA minimum system board, the voltage and current detection circuit of the control circuit are designed; For the problems of the ZVZCS soft switches, the magnetic zero peak of the transformer and the reverse recovery spike of the output rectifier diodes, the RCD snubber circuit of the full bridge inverter and the RC snubber circuit of the rectifier diodes are designed.3. The zero current and zero voltage switching process of limited bipolar control is analyzied and the mathematical model of special power supply is created based on the way of effective duty cycle. The digital PID controller is designed combined the model with the SISO Design Tool of the Matlab software. The control regular patten of the generalized predictive PID control (GPCPID) is derived and the PID control algorithm and GPCPID control algorithm and related auxiliary module software programming are accomplished through the Verilog language, not only this but also conduct the Modelsim simulation and board-level debugging of the PID and GPCPID controller.4. Some relevant experiment tests had been made combined with design parameters, and the effects of the PID and GPCPID control are compared.The results of the testing and comparison verify that the special power supply meets the technical requirements and the GPCPID control can be applied in the closed-loop control of the special power supply well.