Development Of A New Thermal Stimulation Current Test System And Study On Thermal Stimulated Current Of Nano Dielectric

In recent years,the theory of thermal stimulation based on dielectric physics and semiconductor physics has been widely concerned by material researchers.The thermal stimulation current method is an important method to study the dielectric properties and electrical conductivity of materials.It can accurately determine the characteristic parameters such as trap distribution,trap level and relaxation time of dielectric materials,which lays a foundation for the vigorous development of dielectric materials.basis.Nano-dielectrics have the advantages of high field strength resistance,good space charge suppression performance,and easy preparation.They are the development trend of dielectric materials in the future.In this paper,a new thermal stimulation current test system is designed,which has the advantages of high polarization voltage,accurate temperature control,high automation and simple operation.The test system uses vacuum polarization to measure the thermal stimulation current.The ultimate pressure of the vacuum system can reach the order of 6×10-4Pa.There is no pipe joint in the vacuum chamber,which eliminates the leakage of refrigerant in the vacuum chamber during cooling..The electrode part of the test system is small in volume and low in heat capacity,which is beneficial to improve the temperature control accuracy during the test;the semiconductor cooling sheet is used for temperature reduction,the cooling rate is controllable,and the minimum temperature can reach-50 ° C,which can meet the testing requirements of most materials.And can achieve low temperature polarization.When the measurement requires a lower cooling temperature,it can be replaced by a liquid nitrogen cooling method;when the temperature is lowered,the electrode can be separated from the cooling device to improve the temperature control accuracy,and the non-inductive ceramic heating piece is used as a heating source to reduce the electrode and the cold source.The distance between the electrodes increases the temperature rise and fall efficiency of the electrode device;the entire current test circuit is grounded and has strong anti-interference ability.The control software is written in labview.The humanmachine interface has good interactivity and is easy to use.It can basically complete automated measurement.In this paper,a new thermal stimulation current test system was developed to treat pure LDPE,nano-zeolite polyethylene doped with 0.5wt%,1wt%,2wt%,3wt% and nano-A200 vapor phase SiO2 polyethylene with the same concentration gradient.Testing and analysis.The test results show that the thermal stimulation current curve of polyethylene changes significantly after doping with nanoparticles.Both nanoparticles increase the peak of the thermal stimulation current of the polyethylene.The higher the doping concentration of the nanoparticles,the larger the peak of the thermal stimulation current and the higher the trap density.The effect of the two kinds of nanoparticles on the trap depth is different.The nano zeolite particles can make the thermal stimulation current peak of the polyethylene nanocomposite move to the low temperature,while the polyethylene composite material doped with the nano SiO2 particles has the peak value of the thermal stimulation current.The effect of temperature is small.