Research On Dynamic Optimal Control Strategy Of Medium Frequency And High Pressure Dedusting Power Supply

As the core equipment of the electric dust removal system,the performance of the dust removal power has a decisive effect on the dust removal effect.In the context of the country’s continuous improvement of industrial dust emission standards,it is of great significance to further improve the performance of the dust removal power.The related research on the dust removal power supply circuit topological form has been relatively mature.Therefore,the improvement of the power supply control method has become the key to improve the dust removal performance of the dust removal power supply.The theory and practice show that the main factors affecting the dust removal efficiency of the dust removal power supply are the output power of the power supply,the detection and treatment of spark flashover,and the treatment of anti-corona phenomenon.This thesis selects the widely used intermediate frequency dust removal power supply as the research object,and takes the influencing factors of dust removal efficiency as the starting point to design a dynamic optimization control strategy for the dust removal power supply to improve the control effect of the power supply and ensure the dust removal efficiency of the dust removal power supply.The working mode of the circuit of the intermediate frequency dust removal power supply is firstly analyzed,then a static mathematical model of the circuit in the continuous current mode and the intermittent current mode are established,and the quantitative relationship between the control amount and the output amount of the circuit at the static operating point is obtained.Based on the static mathematical model,the dynamic mathematical model of the circuit is further established to obtain the transfer equation from control to output,which provides a theoretical basis for the design of the control system.The analysis of the influence of the inverter frequency of the inverter section on the power supply output is the basis for the transformer selection and control output.Then according to different working conditions,constant voltage control mode,constant current control mode and pulse power supply control mode are designed.In the constant voltage control mode,in order to suppress the influence of load disturbance on the output voltage,a fuzzy PI control strategy is designed to enhance the stability of the output voltage.In the constant current control mode,the width of the current hysteresis loop is dynamically adjusted according to the output voltage,and the switching frequency of the IGBT is controlled to be approximately constant,which overcomes the shortcomings of the current hysteresis loop control.At Last,the detection and control strategy of anti-corona phenomenon is designed,the pulse power supply to suppress the adverse effect of anti-corona on the dust removal efficiency is used.Then the change characteristics of circuit variables is analyzed when the spark flashover occurs in the intermediate frequency dust removal power supply.According to the mathematical equation of the circuit when the spark flashover occurs,a new spark flashover detection method is put forward,and an external circuit is designed to realize the spark flashover detection function.Finally,the software and hardware system of the power control part is designed,and the feasibility of the designed control strategy is proved by experimentally measured waveforms and actual operation on the industrial site.