| Pulsed Electro-Acoustic method (PEA) has been extensively used for space charge measurement of polymers, and it was also used to investigated the space charge of polymer under different temperature. However, the influence of temperature on the hardware of PEA system and the test sample would disturb the stability of PEA system and the reliability of space charge calculation results. Based on the principle of PEA, the probably influences of temperature on the PEA system has been analyzed, and the temperature influence on space charge measurement of polymer insulating material has been investigated.The analysis of PEA space charge density measurement and calculation show that the system transfer function of PEA would be different due to the hardware parameters changing as the change of test temperature. Though the sound velocity change of test sample would also bring distortion into the space charge calculation under varied test temperature, the above influences might be reduced using the right transfer function through two times measurements at a same temperature. According to above analyses, this paper put forward a simply measurement way to reduce the distortion of space charge calculation which is based on the real-time sound velocity of the test sample under different test temperatures. By selecting air gap as the referenced sample, it was confirmed that the calculation of space charge would be much more accurate using the simply measurement way for varied temperatures based on the real-time sound velocity. In addition, the investigation on the low-density polyethylene under different temperatures has also verified the feasibility of the simply measurement way.This study would contribute to improve the accuracy of PEA measurement at different temperatures. |
