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Full-Text Articles in Engineering
Multiple Discharges Before Leader Inception In Long Air Gaps Under Positive Switching Impulses, Xiangen Zhao, Juhyeong Lee, Gang Liu, Lei Jia, Yang Liu, Junjia He, Yaping Du
Multiple Discharges Before Leader Inception In Long Air Gaps Under Positive Switching Impulses, Xiangen Zhao, Juhyeong Lee, Gang Liu, Lei Jia, Yang Liu, Junjia He, Yaping Du
Mechanical and Aerospace Engineering Faculty Publications
There are multiple corona bursts before leader inception when the rising rate of the applied voltage or electric field is not sufficiently high enough in long positive sparks. In existing studies, no attention has been paid to whether these corona bursts occur in the same location, and they are mostly considered directly as belonging to the same discharge. However, this paper presents that in a typical rod-plate long air gap, the multiple corona bursts before leader inception are distributed in at least two different locations, and the highest probability of three discharges occurs. Also, the discharge occurs with the highest …
Schlieren Techniques For Observations Of Long Positive Sparks: Review And Application, Junjia He, Xiankang Wang, Xiangen Zhao, Juhyeong Lee, Yaping Du, Xiaopeng Liu, Quan Gan, Yang Liu, Yuqin Liao
Schlieren Techniques For Observations Of Long Positive Sparks: Review And Application, Junjia He, Xiankang Wang, Xiangen Zhao, Juhyeong Lee, Yaping Du, Xiaopeng Liu, Quan Gan, Yang Liu, Yuqin Liao
Mechanical and Aerospace Engineering Faculty Publications
Understanding the mechanism of positive leader discharge is important in lightning protection engineering and the external insulation design in high voltage power transmission systems. During the propagation of a positive leader, some processes without light-emitting, for example, the insulation recovery process after the breakdown, cannot be observed by optical photography techniques. With the combination of the digital high-speed imaging system, the conventional Schlieren techniques offer new vistas in the long air gap discharge observation. The important features of high spatial resolution, high sensitivity, and easy arrangement make Schlieren techniques powerful and effective tools for characterising the discharge processes without light-emitting. …