Design And Research Of Gas Insulated Tesla Transformer In Electromagnetic Pulse Technology

In recent years,electromagnetic pulse technology has occupied an increasingly important position in the fields of high-tech and military.As one of the boosting components of electromagnetic pulse power system,the Tesla transformer has the advantage of compact structure,which accords with the new development trend of electromagnetic pulse technology.In view of the fact that most Tesla transformers adopt oil insulation medium,the gas insulated Tesla transformer with large coupling coefficient is designed in order to reduce the total weight of the transformer.And the simulation and experimental research are done.In this paper,the Tesla transformer circuit is analyzed theoretically.The approximate expression of the primary and secondary voltage and current are obtained through detailed deduction process.The electric field strengths of two structures of pulse forming lines are analyzed and compared.The main parameters of the line are calculated theoretically.The distribution of electrostatic field of the pulse forming line is simulated and analyzed by ANSYS.The designed pulse forming line is 0.6m long,and its maximum diameter is less than 0.2m,which accords with the requirement of miniaturization.The whole structure of Tesla transformer is designed and its main parameters are calculated theoretically by using the large coupling coefficient approximation theory.The coupling coefficient of the designed Tesla transformer is about 0.970,which satisfies the requirement of large coupling coefficient.The working process of Tesla transformer circuit is simulated by Multisim.And the influence of stray parameters on charging voltage waveform of pulse forming line is studied.The secondary capacitor reaches a peak charging voltage of 439kV at 4.967?s.A voltage pulse about 206kV can be obtained on a 25?resistive load and its half-peak width is over 4ns.At last,the insulation properties of pure SF₆ gas,pure CF₃I gas and50%CF₃I/50%N₂ gas mixtures in the designed Tesla transformer are studied and analyzed by power frequency and lightning impulse test.The experimental results indicate that 50%CF₃I/50%N₂ gas mixtures can achieve nearly 78%insultation strength of pure SF₆ gas.Based on the comparison of insulation strength,liquefaction temperature and environmental protection property,the paper proposes that CF₃I/N₂ gas mixtures with appropriate content has great potential to be used in the designed Tesla transformer as an environment-friendly insulation medium.And the recommended working pressures of pure SF₆ gas and50%CF₃I/50%N₂ gas mixtures in the Tesla transformer are 0.4MPa and0.5MPa respectively on the basis of estimation and calculation.