Grounding transformer in operation, as the winding through the current will produce core loss and winding resistance loss, etc., these losses will lead to transformer heating, so that insulation deterioration, affecting the output and life of the transformer mouth, so, by improving the heat dissipation capacity of the transformer to improve the capacity of the transformer, has become an important measure.

At present, grounding transformers commonly used cooling methods are generally divided into three oil-immersed self-cooling, oil-immersed air-cooled, forced oil circulation.

Oil-immersed self-cooling type is to take the natural convection effect of oil to bring the heat to the oil tank wall and heat sink tube, and then rely on the convection conduction of air to dissipate the heat, it has no special cooling equipment. The oil-immersed air-cooled type is based on the oil-immersed self-cooling type by adding a fan to the tank wall or heat sink tube and using a blower to help cooling. After the addition of air cooling. It can increase the capacity of transformer by 30%~35%. Forced oil circulation cooling method, and divided into strong oil air cooling and strong oil water cooling two. It is the oil in the transformer, using the oil pump to hit the oil cooler and then back to the oil tank. The oil cooler is made into a special shape for easy heat dissipation using fan blowing air or circulating water cooling medium to take away the heat. This forced oil circulation cooling method increases the oil circulation speed by 3 times compared to the white convection. The capacity of the transformer can be increased by 3%.