JOURNAL / ISSUES               ISSN 2310-6697 / ISSN-L 2310-6697
open transactions on independent scientific-engineering research

ISSUE 7 - SUNDAY 31 MAY 2015 - YEAR 2

Attribution 4.0 International License CC BY 4.0
# Electrical Engineering - Théorie
Thoughts on the Possibility of Damage
of High-Voltage Electrical Insulation
below the so-called Inception Voltage:
The Historical Background - Part I
M. G. Danikas, Yi Yin, Jialei Hu
Partial discharges (PD) may cause damage to high-voltage (h.-v.) electrical insulation and eventually breakdown. It is known, however, that sudden breakdowns occurred in industrial insulations after only a few months in service, although they had passed the suggested international specifications tests. In this paper, we investigate the possibility of damage of an h.-v. insulation even below the inception voltage, giving the historical background which led to certain thoughts. References to previous work are given and a differential equation is proposed regarding the possibility of having charging phenomena below the inception voltage.
# Telecommunications Engineering - Applications
A Planar Delta-Cross Shaped Loop Antenna:
Analysis and Simulation - The 2 WL Case
G. A. Papadaniel, N. I. Yannopoulou, P. E. Zimourtopoulos
A planar Delta-Cross shaped loop antenna is proposed. The presentation includes results from an analytic study of the radiation pattern, as well as, from a simulation study for both the electric and radiation characteristics: input impedance, standing wave ratio, radiation pattern and directivity. The loop was initially shaped as 4 non-overlapping equilateral triangles on a plane, symmetrically oriented around a common vertex, center fed at one triangle base. In order to improve the antenna characteristics, its shape was then modified by equally changing the triangle base angle—while keeping the loop length constant and equal to 2 wavelengths WL. In this way, the final antenna loop was shaped with 4 isosceles triangles. The analytical and simulated results for the radiation pattern were found to be in good agreement. Furthermore, a comparison with antenna's dipole counterpart characteristics showed a much better performance of the proposed antenna.