Partial discharge (PD) under a sequence of high-repetition-rate square pulses is one of the key factors leading to premature failure of insulation systems of inverter-fed motors. Polyimide (PI) film is an important ty...Partial discharge (PD) under a sequence of high-repetition-rate square pulses is one of the key factors leading to premature failure of insulation systems of inverter-fed motors. Polyimide (PI) film is an important type of insulating material used in the inverter-fed motors. In this paper, micro-morphology and structure change of PI film aged by bipolar continuous square impulse voltage (BCSIV) with ampli- tude above partial discharge inception voltage (PDIV) are investigated by scanning electron microscope (SEM). The chemical bonds of PI chain are analyzed through Fourier transform infrared spectroscopy (FTIR). The results show that the degradation mechanism of PI film is the fracturing of chemical bonds caused by the erosion from PDs. Three layers are displayed in both 100 HN film and 100 CR film. The de- gradation path of PI film is initiated from surface and then gradually extends to the interior with continuous aging. Nano-fillers can retard the degradation of PI film and prolong its lifetime.展开更多
针对特定环境下110 k V线路穿越其他高等级电压线路的方案开展了深入的研究分析,通过对该方案的现状与制约因素分析研究,提出了一种双回高压线路穿越杆方法,该方法采用水平加垂直混合方法布置导线,彻底解决了被穿越线路上下安全距离不...针对特定环境下110 k V线路穿越其他高等级电压线路的方案开展了深入的研究分析,通过对该方案的现状与制约因素分析研究,提出了一种双回高压线路穿越杆方法,该方法采用水平加垂直混合方法布置导线,彻底解决了被穿越线路上下安全距离不够的问题,同时使得线路更加紧凑,且又保证了导线对地足够的安全距离。展开更多
基金Project supported by National Natural Science Foundation of China （51177136）.
文摘Partial discharge (PD) under a sequence of high-repetition-rate square pulses is one of the key factors leading to premature failure of insulation systems of inverter-fed motors. Polyimide (PI) film is an important type of insulating material used in the inverter-fed motors. In this paper, micro-morphology and structure change of PI film aged by bipolar continuous square impulse voltage (BCSIV) with ampli- tude above partial discharge inception voltage (PDIV) are investigated by scanning electron microscope (SEM). The chemical bonds of PI chain are analyzed through Fourier transform infrared spectroscopy (FTIR). The results show that the degradation mechanism of PI film is the fracturing of chemical bonds caused by the erosion from PDs. Three layers are displayed in both 100 HN film and 100 CR film. The de- gradation path of PI film is initiated from surface and then gradually extends to the interior with continuous aging. Nano-fillers can retard the degradation of PI film and prolong its lifetime.
