Research On Discharge Behaviors Of Short Air Gap Under Pulse Voltage And Experiment Analysis With Dielectric-covered Electrodes

Discharge with dielectric-covered electrode is a spectial discharge model with the electrode is covered by dielectric.Meantime,discharge with dielectric-covered electrode and also is one of the main devices to generate low temperature plasma.Especially the development of pulsed power technology made a great contribution to the discharge with dielectric-covered electrode.Due to the discharge with dielectric-covered electrode under pulse voltage has a significant advantage,the application in the industrial become more widely.And with the increase of the complexity of the grid,the impact on the electrical equipment of pulse voltage is also being attentioned.So study on the discharge with dielectric-covered electrode under impulse,not only may provide the scientific data for monitoring of the power system operation status monitor,but also can offer theoretical foundations for the insulation coordination and the structure optimization.One-dimensional self-consistent hydrodynamics of gas discharge model is established in the dissertation,including particle kinerics equation and Poisson equation,numerical simulation of the dynamical behavior of the short air gap discharge with dielectric-covered electrode under lightning impulse,nanosecond pulse and VFTO impulse.The results show that the discharge has avalanche stage and streamer stage under lighting impulse.Electric field distortion and the developing of streamer are influenced by space charge.The discharge current shows the bipolar under nanosecond impulse.The affect on the discharge by external parameters was analyzed.In this dissertation the unique discharge characteristics under VFTO pulsed also analyzed.The experiment of the discharge with electric covered electrode is also designed.The informations of discharge current under different Electrode structure are obtained.The current signal,which consistent with the theoretical simulation result,shows significant differences under different electrode structures.The signal is analyzed,which is an effective time-frequency analysis method for observing the time-frequency property of discharge current in the short gas-gap.The consequence is excting satisfaction,which extract frequency energy of discharge current and take as features for pattem recognition.