| With the maturity of the electrolytic industry and the advancement of science and technology,the electrolytic industry has put forward higher requirements for the adaptability,timeliness and reliability of power supplies.Aiming at the existing problems of power supply,this paper study a high frequency electrolytic power supply of 800A/40 V,which is composed of a front-stage Voltage Source PWM Rectifier(VSR)and a back-stage phase-shifting full-bridge converter(ZVS).It has the advantages of less harmonic content,high transmission efficiency and good stability,the output voltage and current of the system can be adjusted according to the process requirements to better meet the electrolysis needs,which are of great significance for achieving high-purity tellurium extraction,energy saving and emission reduction,and improving the power quality of the power grid.The main research contents and innovations are as follows:Firstly,this paper introduces the research status of electrolytic power supply at home and abroad,and compares the advantages and disadvantages of different topology of power supply,at the same time,the key technologies and control strategies that affect the switching power supply technology are deeply analyzed.Finally,the AC/DC/DC two-stage electrolytic power supply is chosen as the research object,and the working principle of the power supply is analyzed theoretically.Aiming at the existing problems at various stages of power supply,The intelligent control algorithm is introduced to optimize the design and analysis of the high-power dc power supply system according to the requirements of electrolytic tellurium process,so as to improve the stability and reliability of the power supply.Secondly,in the process of power supply pre-stage optimization design,By analyzing the working principle of PWM rectifier and designing parameters,The mathematical model under?? coordinate system is established to further study the SVPWM modulation technology.For the problems of high harmonic content and low power factor in the front stage,MPC-DPC is proposed for pre-stage,The objective function is designed by the square minimum of the error between the power reference value and the predicted value.This method can realize online rolling optimization and error feedback correction,and it has the advantages of good control effect and strong robustness.Through MATLAB simulation experiment,and compared with the traditional DPC.The results show that under this control strategy,the network side harmonic content(THD%)is only 2.35%,the power factor is 0.9992,and the system dynamic response is fast,the voltage is stable and reliable,which verifies the rationality and effectiveness of the proposed method.Finally,in the process of optimization design of power supply post stage,the working mode,circuit parameter design and soft switch technology of ZVS phase-shifting full bridge DC / DC converter are analyzed.A small signal model based on state space averaging method is established,and the traditional PI double closed loop controller is deeply analyzed by transfer function Bode diagram.In order to solve the problems of small output range,low transmission efficiency and poor dynamic performance of traditional PI control system,a power supply post stage control strategy based on Fuzzy PI control is proposed.This control method has the advantages of simple control and strong adaptive ability,and can realize the online correction of PI parameters through fuzzy controller.The power system is built in MATLAB,and compared with the traditional PI controller,the effectiveness of the fuzzy PI control algorithm is verified.The DC side voltage has the characteristics of good stability,small overshoot and strong robustness.The validity and reliability of the high power electrolytic power supply designed in this paper are further proved. |
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