A transformer cooler is a device that removes heat from the transformer through heat dissipation to maintain its normal operating temperature. The function of a transformer cooler is to ensure that the transformer operates within a reliable and safe temperature range, thereby extending its service life.

Transformer coolers primarily operate using two methods: natural cooling and forced cooling.
Natural cooling involves the transformer using natural convection to dissipate heat into the surrounding environment. Natural coolers typically take the form of a radiator, typically consisting of a series of fins and cooling oil. The cooler is mounted on the top or side of the transformer and dissipates heat through the circulation of cooling oil. When the transformer is operating, a large amount of heat is generated within the transformer, causing the transformer temperature to rise. This heat is then transferred through the coils and core to the cooling oil. As the cooling oil flows through the radiator, it dissipates the heat through radiation and convection, thereby reducing the transformer temperature.

Forced cooling involves using external cooling devices to accelerate the heat dissipation process. Generally speaking, when the transformer current or load is high, natural cooling often fails to meet the required temperature. In such cases, a forced cooler is required to improve cooling efficiency. Forced coolers typically include components such as a fan, a cooler, and a coolant. A forced cooler uses a fan to lower the coolant temperature to an appropriate range, then transfers the heat to the ambient air through the cooler's fins. This method effectively reduces transformer temperature and improves transformer operating efficiency and reliability.

The function of a transformer cooler is to ensure a stable and reasonable operating temperature for the transformer. Excessive transformer temperature can lead to insulation degradation, degraded electrical performance, and even cause faults such as short circuits and explosions. A transformer cooler effectively and promptly removes heat generated within the transformer, keeping the transformer operating within a safe temperature range and preventing these problems. Furthermore, a good cooling system can reduce transformer temperature rise, increase its load capacity, and extend its service life.

A transformer cooler uses both natural and forced cooling to dissipate heat from the transformer, ensuring it operates within a safe temperature range. The function of a transformer cooler is to protect the transformer's electrical and mechanical properties, extend its service life, and improve its reliability and operating efficiency. Therefore, it is crucial to properly select and configure the cooling system when designing and selecting a transformer.