(b) Suspended Particle Mechanism:
The presence of solid impurities cannot be avoid-
ed. These impurities will be present as fibers or as
dispersed solid conducting particles, especially in
transformers. The fibrous particles are disposed-off
from Bakelite or cloth insulation of the winding,
whereas the conducting particles are introduced
from steel tank structure during service conditions.
These particles are polarized under the influence of
electric field and thereby are aligned forming a sta-
ble chain binding the gap causing short circuit re-
sulting in break down as shown in fig (IV) below.
If there is only a single conducting particle, it will
give rise to local field enhancement depending on
its shape. If this localized field exceeds the break-
down strength of the liquid, local breakdown will
occur near the particle, and this will result in the
formation of gas bubbles, which may lead to the
breakdown of liquid by Cavitation mechanism.
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