| Electrostatic dust removal can effectively remove the solid particles in industrial waste gas,so it is widely used in places where industrial waste gas is discharged in thermal power plants,steel plants and other places.Plasma can be used to remove sulfides and nitrides in industrial waste gas.The high-voltage DC power supply of the electrostatic precipitator can no longer meet the increasingly stringent emission requirements,and the generation of plasma needs to rely on nanosecond pulse discharge power,so the innovation of pulse power power technology is imminent.Due to its short duration,effective suppression of back corona,high efficiency and energy saving,pulsed power technology has emerged in the fields of dust removal,desulfurization and denitrification,and how to increase the peak output voltage and sharpen the pulse front has become a hot and difficult research topic.With the goal of achieving high-voltage narrow pulses,and taking high repetition frequency efficiency as the development direction,this paper proposes a pulse generation scheme,supported by magnetic compression technology,in-depth study of the operating characteristics of pulse generation circuits and magnetic compression networks,and design system control Program.Finally,the prototype design and experimental verification of a nanosecond pulse power supply with a rising edge of 890 ns is completed.First of all,this paper studies the working principle and output characteristics of a nanosecond pulsed power supply based on magnetic compression technology.The front-stage pulse generating circuit adopts a top and bottom symmetrical series topology to output a microsecond pulse voltage;the latter stage uses a two-stage magnetic compression circuit to complete the rising edge steepening,and finally outputs a nanosecond pulse voltage.The working principle of the power supply in each stage is analyzed,the mathematical model of the resonant circuit is established,and the output characteristics of the power supply in each stage are analyzed.A simulation model of the nanosecond pulsed power supply was built,and the simulation verified the correctness of the theoretical analysis.Secondly,the design method of the magnetic switch applied to the nanosecond pulse power supply is introduced,including the optimization of the magnetic parameters of the magnetic switch and the optimal design of the core cross-sectional area and the number of turns.The PLECS simulation software is used to analyze the influence of the magnetic parameters of the magnetic switch on the output of the system,and based on the simulation results,the optimal selection of the magnetic core material is completed.By building a magnetic core test circuit,the magnetic core hysteresis curve is measured,and the key magnetic parameters are obtained.Based on the theoretical derivation and combining with the principle of minimum magnetic switch volume,the optimal solution of the cross-sectional area of the magnetic core and the number of turns is obtained.The reset circuit of the magnetic switch is analyzed,and the best reset time is derived.Third,the paper analyzes the hardware structure and control mechanism of the system.Completing the calculation of power circuit parameters,considering the complexity of the system,a collaborative controller based on DSP and FPGA is designed,and IGBT drive isolation circuit,level conversion circuit,pulse peak sampling circuit and magnetic switch opening detection circuit are designed.The principle of magnetic switch control is analyzed,and a magnetic switch control process suitable for nanosecond pulse power is proposed.Finally,the test platform construction and prototype design are completed in the laboratory.The experimental results show that the output characteristics of the circuit are consistent with the theoretical analysis and simulation results.The peak output voltage of the power supply prototype is 80 k V and the rising edge width is 890 ns,which all meet the design requirements. |
PDF Full Text Request