Why does the temperature of the switchgear increase

There are three reasons for the high temperature of high-voltage switchgear:

The first is the resistance loss and heating of the high-voltage switchgear. During the long-term operation of the power system, the heat generated by the equipment is not discharged from the cabinet in a timely manner. When the heat accumulates to a certain extent, the equipment will experience aging problems. After the aging problem occurs, the load that the equipment can bear will be greatly reduced, but the load transmitted to the high-voltage switchgear has not been correspondingly reduced. The voltage and current values passing through the high-voltage switchgear have not changed significantly, resulting in an increase in resistance heating;

Secondly, the medium loss inside the high-voltage switchgear generates heat. The insulation medium inside the high-voltage switchgear is affected by the alternating electric field, and its poles constantly change. During the change, the poles are limited by the voltage and current effects, resulting in a decrease in the nature of the insulation. Friction or collision between equipment inside the high-voltage switchgear causes frequent equipment leakage accidents. In such accidents, the insulation material will also heat up to a certain extent due to the influence of electrical equipment. After the insulation material heats up, it will further reduce its insulation performance, and in a cycle, the temperature of the high-voltage switchgear will gradually increase;

Thirdly, the iron loss and heating of the high-voltage switchgear. In the process of current flow, the hysteresis and eddy currents of the iron core on the circuit circuit circuit are equivalent to a resistor due to the influence of voltage. During the process of maintaining current operation, there is iron loss in the iron core, and its resistance also decreases to a certain extent.