Research On High Voltage Switch Type Pulsed Power Supply For Electrostatic Precipitator

Electrostatic precipitator(ESP)is one of the most important means to control smoke emission and solve air pollution nowadays.With the increasingly serious environmental problems,countries around the world have set higher standards for industrial smoke emissions.For the traditional ESP with DC corona charge,spark flashover occurs frequently in the electric field of the precipitator.It is easy to occur back corona when charging the dust with high specific resistance,so it is hard to reach a higher dust emission standard.Compared with it,the pulsed power supply can solve the above problems effectively.The efficiency of dust collection is higher,so it has become one of the main development trends of ESP power supply.Based on the theory of electrostatic precipitation and the development status of ESP power supply at home and abroad,the advantages and significances of HV switch type pulsed power supply for ESP are discussed in this paper.and focuses on its circuit characteristics,coupled inductor design,control mechanism and system circuit structure design.Firstly,the characteristics of HV switch type topology and the design method of resonant circuit are studied.According to the main circuit topology,the working principle of the circuit is described,and the mathematical model of the resonant circuit is established.The resonant and spark state of the circuit are analyzed in detail.Based on the mathematical model of the circuit,the design method of resonant circuit parameters is proposed,it also provides a theoretical basis for the design of ESP control system.Secondly,the design method of coupled inductor applied to HV switch type topology is studied,including the calculation method of inductance value and the optimal design method of winding structure.Based on the expression of inductor current ripple,the relationship between the inductors is determined,and the influence of the coupling coefficient is analyzed.The mathematical models with coupled inductance value as variable are established.Then the influence of inductor value on output is analyzed according to the mathematical models,the value of coupled inductor matching with the system is obtained.Considering the high frequency model of coupled inductor,an engineering method based on ANSYS finite element simulation(FAE)is proposed to optimize the structure of inductor windings,which can realize the minimum distributed capacitance design of single winding.In order to verify the feasibility of the optimization method,the coupled inductors with different winding structures are designed and manufactured for comparative analysis.Thirdly,this paper summarizes the design method of HV switch type pulsed power supply.According to this method,the design process of circuit parameters of simulation prototype in this subject is introduced,and the correctness of theoretical analysis is verified by circuit simulation.According to the simulation results of the system under steady and unsteady conditions,a control mechanism suitable for HV switch type pulsed power supply is proposed,including automatic control of system operation parameters and spark flashover protection control.Finally,the system circuit structure of HV switch type pulsed power supply is constructed,including resonant circuit,coupled inductor,power supply,auxiliary power supply and control system.And a simulation prototype with pulse width of 20 ?s and pulse amplitude of 1.45 kV is built for experimental verification.The experimental results are basically consistent with the theoretical analysis and simulation results,which proves the feasibility of the proposed technical scheme.