电声脉冲法中脉冲对空间电荷分布测量的影响

首先阐述了目前已广泛应用的电声脉冲法(PEA)测量电介质中空间电荷的原理,介绍了一台新型的PEA空间电荷测量装置(其电脉冲幅值和宽度可调),并利用此装置在相同的测试条件下测量了相同的试样。研究发现:对固定厚度的传感器来讲,空间电荷分布信号随脉冲幅值增加而增加,且其波形随脉冲宽度增加而展宽和增强。最后根据PEA测量空间电荷的原理合理分析了上述的现象。

Influence of Pulse Waveform on Space Charge Distribution in the Pulse Electroacoustic Method

At first,the principle of pulsed electroacoustic(PEA) method is described.The PEA is used widely to study space charge distribution in solid dielectric materials by many researchers.Although the PEA method for measuring the space charge in solid has been developed for twenty years,but the whole measurement system also has some defects and needs further development.A new space charge measurement system of PEA is developed,and its amplitude and width of pulse are adjustable.In order to study the influence of pulse waveform on space charge distribution in solid,the space charge of a polyethylene sample is measured with various width of electric pulses.From the results of experiment,it can be seen that the amplitude of signal of space charge distribution increases with increasing of amplitude of electrical pulse,particularly the signals near the electrodes.Moreover,with increasing width of electric pulses,the space charge distribution signals change a lot,such as broadening of waveform and increasing of amplitude.At last,on the base of the physical principle of PEA for space charge measurement,the above mentioned phenomena are discussed in details.