Physics for Electrical Engineering: Unit I: Dielectric Materials and Insulation
Dielectric Strength
Definition, Formula, Factors
The voltage at which breakdown occurs is called breakdown voltage. This is also called disruptive voltage. It is expressed in volts.
DIELECTRIC
STRENGTH
The
voltage at which breakdown occurs is called breakdown voltage. This is also
called disruptive voltage. It is expressed in volts.
The
intensity of the electric field at which breakdown occurs is called the
dielectric or electric strength.
Ie.,
Dielectric strength = Breakdown voltage / Thickness of the dielectric
It
is expressed in kV/cm or kV/mm.
The
value of dielectric strength depends upon the following factors:
(i) Sample thickness
(ii) Temperature
(iii) Applied frequency
(iv) Wave formelor
(v) Electrode form
(vi) Area
(vii) Thermal conductivity
(viii) Surrounding medium
(ix) Rate and total time of voltage
application.
Dielectric breakdown
When the strength of electric field applied to a dielectric exceeds a critical value, very large current flows through it. The dielectric loses its insulating property and becomes a conductor. This phenomenon is known as dielectric breakdown.
Physics for Electrical Engineering: Unit I: Dielectric Materials and Insulation : Tag: : Definition, Formula, Factors - Dielectric Strength
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Physics for Electrical Engineering
PH3202 2nd Semester 2021 Regulation | 2nd Semester EEE Dept 2021 Regulation