| Polyethylene insulation material plays an important role in the transmission of electrical energy and is the main material used for the insulation of AC and DC high-voltage cables.Therefore,studying the electrical aging and breakdown properties of polyethylene insulation materials has become a popular direction in the field of high-voltage insulation.However,due to its complex structure and the lack of mature theoretical and physical models to support it,its research methods and methods are not single.Among them,the study of the luminescence spectrum of polyethylene under DC electric field is a good method.This paper mainly studies the luminescence phenomenon of polyethylene near the breakdown field strength.Due to its luminescence and its weakness,the test is difficult.It is necessary to repeatedly test to select the light integration time.If it is too small,the signal cannot be collected.Larger signal interference is more serious.Firstly,the Lab VIEW can be used to run in parallel and the single-chip system realizes a trigger device capable of two-way communication at the same time.Secondly,some related tests are carried out on the measurement system itself,including: background noise attenuation trend,correction of spectral accuracy Testing and imaging testing,etc.The final results show that this set of devices can achieve the collection of low-density polyethylene(LDPE)weak spectral signals and imaging.Finally,the built experimental device was used to test the LDPE imaging and the spectrum test of different field strengths under positive and negative high pressure.The spectrum test shows that: at 200 k V/mm under positive high voltage,there is a peak at 580 nm,and under negative high voltage,there are two peaks,respectively 521 nm and 588nm;under the field strength of 250 k V/mm,when applying positive high voltage,it will be at 408 nm,506nm,583 nm,69 5nm,the peak appears at 510 nm,588nm when applying negative high voltage;under the field strength of 300 k V/mm,the peak appears at 410 nm,503nm,586 nm,708nm when applying positive high voltage.Peaks will appear at 415 nm,520nm,586 nm,and 711 nm when a negative high voltage is applied.Through the comparison between positive and negative high voltages,it is found that after the LDPE reaches the electroluminescence threshold electric field,the LDPE electroluminescence under the DC electric field is basically the same.Using the measured light intensity data,a graph of the relationship between the average light intensity and the electric field intensity is made.After the threshold electric field of the material’s electroluminescence is reached,the luminous intensity will increase as the field intensity increases,roughly After 300 k V/mm,the luminous intensity will increase sharply. |
