- What causes electrical tracking?
- How does the internal discharge phenomena lead to breakdown in solid dielectrics?
- What is tracking in High Voltage?
- How do the temperature and moisture affect the breakdown strength of solid dielectrics?
- What is called tracking?
- What is thermal breakdown in solid dielectrics?
- What is the bubble breakdown theory?
- Which of the following test is done to detect the presence of moisture in the insulating oil?
- What is cause of presence of moisture in oil of transformer?
What causes electrical tracking?
Surface Tracking is the propagation of an electrically conductive path along the surface of an electrical insulator due to the breakdown of the insulation material.
Tracking develops from surface discharge activity associated with the flow of leakage current, especially under wet or contaminated conditions..
How does the internal discharge phenomena lead to breakdown in solid dielectrics?
These internal discharges (also called partial discharges) will have the same effect as “treeing” on the insulation. When the breakdown occurs in the voids, electrons and positive ions are formed. They will have sufficient energy and when they reach the void surfaces they may break the chemical bonds.
What is tracking in High Voltage?
The High Voltage Tracking Resistance (HVTR) test method is used to assess the susceptibility to tracking of insulating materials that are exposed to high voltages outdoors. … Their electrical insulation properties can deteriorate to such an extent as a result that tracking paths are formed on the insulator surface.
How do the temperature and moisture affect the breakdown strength of solid dielectrics?
Temperature : Dielectric Strength decrease with increase in Temperature. In Higher temperature Electrical Breakdown occurs at lower amount of voltage. … Moisture: • The presence of even 0.01% moistures reduces its electrical strength to 20% . It is due to that moisture increases the conductivity of the medium.
What is called tracking?
1. tracking – the pursuit (of a person or animal) by following tracks or marks they left behind. trailing.
What is thermal breakdown in solid dielectrics?
When an insulating material is subjected to an electric field, the material gets heated up due to conduction current and dielectric losses due to polarization. temperature Tc for which thermal instability will reach and the dielectric will lose its insulating properties. …
What is the bubble breakdown theory?
Bubble elongation causes field increase in liquid near bubble poles. Breakdown initiates in liquid phase when this field reaches critical value that depends on the liquid sample and the polarity of initiating electrode. The equation of bubble growth is computed.
Which of the following test is done to detect the presence of moisture in the insulating oil?
Dielectric Strength of Transformer Oil Breakdown voltage is measured by observing at what voltage, sparking strands between two electrodes immersed in the oil, separated by a specific gap. A low value of BDV indicates presence of moisture content and conducting substances in the oil.
What is cause of presence of moisture in oil of transformer?
The combination of the heat from the hot oil and the vacuum will cause the moisture in the insulation to ”flash off” and dry the transformer.