Discharge type of high voltage switchgear
Apr 01, 2022
High-voltage switchgear refers to the functions of on-off, control or protection in the power generation, transmission, distribution, power conversion and consumption of the power system.
Discharge type
1. Internal discharge.
When impurities or air gaps appear in the insulation structure of the high-voltage switchgear, it is easy to cause internal discharge under the action of high voltage. During the manufacture of the insulating structure, the electric field distribution of the insulating structure is uneven due to the selection of different media or insulating materials with poor craftsmanship. Internal defects due to improper installation. Internal discharge caused by aging and deterioration of insulators.
2. Creeping discharge.
That is, the discharge phenomenon caused by the surface electric field strength of the insulating structure of the high-voltage switchgear exceeding a certain limit value. The creeping discharge is mainly along the two electrode directions, parallel to the surface of the switchgear insulation structure. When the creeping discharge intensity is large enough, it will penetrate the air and cause the communication between the two electrodes. The main reasons for the surface discharge of the switch cabinet are the dirt on the surface of the insulating structure and the temperature and humidity of the surface gas.
3. Corona discharge.
Because there is no insulating material on the electrode surface, the air and the electrode are in direct contact. When the electric field distribution is uneven and reaches a certain limit, the stronger electrode will break down the air and cause corona discharge. Corona discharges are mainly generated on electrodes of high-voltage electrical equipment exposed to air.
