Insulation materials have strong capacitive behavior. What is the effect of applied high voltage distortions (due to odd order harmonics) on the current signal in insulation materials, such as polymers?
The insulator becoming electrically conductive called dielectric breakdown. Just one example:
https://www.researchgate.net/publication/299398967_Dielectric_Breakdown_Strength_and_Flammability_Properties_of_Flame_Retardant_FillerPLLA-PLA_MicrosphereKenaf_Fiber_Composites
Article Dielectric Breakdown Strength and Flammability Properties of...
The losses in dielectrics are due of conduction and polarization (the last being, generally, the most important term: the molecule rotates according the polarity changing of applied electric field). As consequence when the frequency increases, the losses due of polarization increase also and the insulator is supplementary heated. (Many polymers have polar molecules.) When the insulator works in a variable electric field with high level of higher harmonics its life span decreases.
The tan delta of insulating material is always depending on the frequency applied. Additionally the tan delta and the frequency-tan delta dependence is very much influenced by the humidity content in the insulation.
Dear Youcef,
as the dielectric losses increase with increasing frequency, the insulation material is heated. Long-term increase of the temperature on insulation material of 3 degrees Celsius results in decrease its operational lifetime approximately about one half. It depends on the type of insulation material, see the Montsinger's law.
Sincerely, Bystrík
- Badges
- Science topic
- Similar topics
- Engineering
- Mechanical Engineering