Key Technologies Of High-power High-voltage Pulsed Power Supply

Pulsed power technology plays an important role in the fields of national defense,medical and industrial applications.Different application fields place higher and higher requirements on the performance of high voltage pulse power supplies,which are required to output high voltage,high current,highly-repeated frequency and steep rising edge.IGBTs with good switching characteristics have a good application prospect in highvoltage pulsed power supplies.However,limited to its power capacity,a single IGBT device cannot meet the requirements of high-voltage pulse power supplies,in that the higher the power is,the lower the switching frequency would be.The combination of IGBT series technology and converter parallel technology is an effective solution to highvoltage pulse power supply with high power and high repetition rate.This paper first studies the basic characteristics of IGBT in terms of its working mechanism.Secondly,through an analysis of IGBT turn-on and turn-off process,this paper reveals the factors affecting the voltage equalization of series IGBT.Thirdly,tapping into the analog device simulation of the series operation of the device with the help of PSPICE,this paper delineates the influence of series IGBT non-uniform voltage on the characteristics of the device as well as The simulation also reflects the serious problems in series connection of the device caused by the parasitic parameters of the device and the peripheral circuit.To solve this problem,this paper makes a comparison among several IGBT series voltage equalization schemes,studies both the advantages and disadvantages of each scheme,then gives a final plan.Based on the theoretical analysis and simulation results of Series-Connected IGBT,combining with the technical indexes of high-voltage pulse power supply project,the multiplexed Buck circuit constructed by IGBT series is used in the design process of high voltage pulse power supply in this paper.The main circuit parameter design and device selection are completed according to the technical indicators.The design of main circuit parameters is completed according to technical indicators.On the basis of what have been mentioned above,the main circuit is optimized according to the requirements of high repetition frequency and high power of high voltage pulse power supply.Firstly,the passive snubber circuit is used to solve the problem of series non-uniform voltage,and the parameters of the passive snubber circuit are calculated.We further proves the feasibility of our proposal capitalizing on a calculation of the parameters of the passive snubber circuit by virtue of PSPICE.Secondly,the passive snubber circuit reduces the repetition frequency of high voltage pulse power supply.This paper solves the problem based on the double parallel operation of Buck circuit,selects the phase shift control as the control method of the double Buck circuit,and further analyzes the effect of phase shift control on the performance of high-voltage pulsed power supply,and the superiority of this control method is verified by Matlab software.Finally,a high-voltage pulse power prototype with a power of 10 MW is built.It turns out from the results of our experiments that that the IGBT series operation has achieved good voltage equalization effect by using the passive buffer circuit designed in this paper.The double-buck circuit with phase shift control greatly Improve the output accuracy of the power supply.Through the research work in this paper,the technical bottlenecks such as IGBT series connection and converter parallel connection encountered in the realization of highvoltage pulse power supply are systematically solved,and the prototype design of highpower high-voltage pulse power supply that can be used in industrial field is completed,which has accumulated engineering application experience for the wide application of high-voltage pulse power supplies.