Page 41 - Energize September 2021 HR

TECHNICAL

The insulation coordination between the complete arrester vibration caused by wind must be verified. The Toshiba EGLA was
and the insulator assembly was tested repeatedly under dry and wet vibration tested with more than one million oscillations and its ability
conditions and proved the high reliability of Toshiba EGLA. A follow to withstand the vibration stress was confirmed. n
current Interruption test was conducted under wet and polluted
conditions. The hydrophobicity of the tested arrester unit was Contact Chika Yamada, Toshiba Africa, Tel 011 305-2820,
completely eliminated via a method based on long experience. Such chika.yamada@toshiba.co.za www.toshiba.co.za
test conditions were far more severe than the other test methods
and effectively simulated practical conditions.
A short circuit test was conducted, and the superior safety of
the Toshiba EGLA was confirmed. The test proved that no violent
scattering of fragments harmful to the human body occurred. The
tests were conducted under circumstances where the arrester unit
was shorted by a fuse wire and the arrester unit was pre-failed due
to power frequency over-voltage. The self-extinguishing capability of
open frames was also confirmed.
The vibration test is the key test item. Since a transmission
line arrester is placed on top of the power towers, the effects of

Figure 7: Insulation coordination testing view of the heavy duty EGLA
for 275 kV system in wet condition Figure 9: Short circuit testing view of the heavy duty EGLA unit

Figure 8: Insulation coordination testing view of the insulators for 275 kV Figure 10: Follow current Interruption testing view of the compact EGLA
system for 170 kV system

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