Transformers are critical elements in the accurate and efficient distribution and transmission of electrical power. As with any electronic device, transformers generate heat during operation. If this heat is not removed by cooling systems, the efficiency and lifetime of transformers will be adversely affected.
Transformer cooling system symbols
Transformer cooling systems are identified by a combination of letters. These letters vary depending on the type and application of the cooling method.
- O: Oil
- A: Air
- W: Water
- N: Natural
- F: Forced
Most Common Cooling Methods Used in Transformers
The most common cooling methods used in transformers are as follows;
- ONAN (Oil Natural Air Natural): In this cooling method, the oil and air in the transformer are cooled naturally. The heated oil rises due to its density difference and is then cooled by radiators. This method has the advantages of lower maintenance cost and quiet operation. However, the ONAN cooling method may not provide sufficient cooling in large transformers.
- ONAF(Oil Natural Air Forced): In the ONAF method, the oil circulates naturally inside the transformer while the air flow is increased by a fan. This method, which provides additional cooling capacity, is widely used in power transformers.
- OFAF (Oil Forced Air Forced): In OFAF, transformer oil is forcibly moved by pumps and airflow is provided by fans. OFAF is often used in equipment with large size and high power requirements.
- Oil Forced Water Forced (OFWF): In OFWF cooling systems, oil is circulated by pumps while being cooled by water. In these systems, heat from the oil is transferred to the water, ensuring efficient operation of systems that require high cooling efficiency.
The type of cooling system and method to be used in transformers varies depending on the size, application, and power of the transformer. Equipment that does not have the proper cooling system will have low efficiency and serious safety hazards due to overheating.