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Akram, Shakeel,Wu, Guangning,Gao, GuoQiang,Liu, Yang The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.5
With the continuous development in insulation of electrical equipment design, the reliability of the system has been enhanced. However, in the manufacturing process and during operation under continues stresses introduce local defects, such as voids between interfaces that can responsible to occurrence of partial discharge (PD), electric field distortion and accumulation of charges. These defects may lead to localize corrosion and material degradation of insulation system, and a serious threat to the equipment. A model of three layers of PI film with air gap is presented to understand the influence of interface and voids on exploitation conditions such as strong electrical field, PD activity and charge movement. The analytical analysis, and experimental results are good agreement and show that the lose contact between interfaces accumulate more residual charges and in consequences increase the electric field intensity and accelerates internal discharges. These residual charges are trapped charges, injected by the electrodes has often same polarity, so the electric field in cavities increases significantly and thus partial discharge inception voltage (PDIV) decreases. Contrary, number of PD discharge quantity increases due to interface. Interfacial polarization effect has opposite impact on electric field and PDIV as compare to void.
Shakeel Akram,Guangning Wu,GuoQiang Gao,Yang Liu 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.5
With the continuous development in insulation of electrical equipment design, the reliability of the system has been enhanced. However, in the manufacturing process and during operation under continues stresses introduce local defects, such as voids between interfaces that can responsible to occurrence of partial discharge (PD), electric field distortion and accumulation of charges. These defects may lead to localize corrosion and material degradation of insulation system, and a serious threat to the equipment. A model of three layers of PI film with air gap is presented to understand the influence of interface and voids on exploitation conditions such as strong electrical field, PD activity and charge movement. The analytical analysis, and experimental results are good agreement and show that the lose contact between interfaces accumulate more residual charges and in consequences increase the electric field intensity and accelerates internal discharges. These residual charges are trapped charges, injected by the electrodes has often same polarity, so the electric field in cavities increases significantly and thus partial discharge inception voltage (PDIV) decreases. Contrary, number of PD discharge quantity increases due to interface. Interfacial polarization effect has opposite impact on electric field and PDIV as compare to void.
Xiao Song,Luo Yuanpei,Wu Jingchi,Zhang Can,Rao Yang,Wu Guangning,Deng Zhida,Sykulski Jan K. 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3
High speed trains receive traction electrical energy from a high-voltage catenary via a pantograph catenary system (PCS). As the velocity of trains increases, the traditional PCSs face signifi cant challenges, such as strong aero resistance under highspeed conditions, severe electrochemical corrosion caused by poor contact between the pantograph strip and the catenary, harmful wear both on the pantograph strip and the contact wire produced by high-speed sliding friction between them, etc. The eff ectiveness and reliability of the PCS has a direct impact on the performance and safety of the HTS power supply. In order to alleviate some of these bottleneck eff ects related to the operation of the currently used PCSs, especially under high-speed conditions, this paper proposes a novel confi guration where rotatable pantograph rollers replace the currently used pantograph strips. As the sliding friction is now replaced by rotating friction, this has numerous benefi ts, such as less friction heat, better heat dispersion and improved catenary-tracking performance. Moreover, should the whole system be modularized, it could adapt to diff erent levels of traction power through adjusting the number of rollers.