Effect factors of pulse injection from outer semi-conducting layer of cable in the PEA technology

摘要

In the coaxial cable space charge measurement system based on Pulsed Electro-Acoustic (PEA) method, the coupled mode of pulse is extremely important. The space charge measurement signal has a direct relationship with the coupled pulse. In this paper, based on the method that the pulse is injected into cable from outer semi-conducting layer, the space charge waveform of 10 kV cable has been measured at different distance between ground point and pulse injection point. The different distance between ground point and pulse injection point, the different size of cable and the length of the pulse injection area that affect injection pulse waveform have been studied through the experiment. The experimental results show that as the increase of distance between the ground point and pulse injection point, the signal amplitude of space charge increases gradually. The injection pulse on the pulse injection point related to the ground and cable size. As the increase of distance between ground point and pulse injection point, the pulse amplitude increases and pulse width becomes wider. Under the same ground, the greater the cable size is, the smaller the injection pulse amplitude is. The thickness of the outer semi-conducting layers has little effect on injection pulse.