Common Causes of Transformer Failure and Explosion

Power and distribution transformers play a critical role in electrical power systems, but their reliability is crucial for efficient operation and safety. Transformer failures can lead to significant downtime, increased maintenance costs, and even catastrophic explosions. Understanding the primary causes of transformer failure is essential for preventive maintenance and system optimization. This article explores the common reasons for transformer failure or explosion, focusing on temperature rise, interturn short circuits, cooling system failures, relays, and other contributing factors.

Temperature Rise and Oil Hot Spots

One of the primary causes of transformer failure is the formation of hot spots within the windings, which leads to an increase in the temperature of transformer oil. As the temperature rises, it can cause the formation of gases within the transformer, potentially resulting in pressure build-up and, in severe cases, an explosion. Proper monitoring and maintenance of the temperature levels are critical to ensure the safe and efficient operation of transformers.

Interturn Short Circuits

Interturn short circuits within the transformer windings represent another major factor contributing to failure. When two or more turns in a winding make direct contact, it can cause a short circuit. This phenomenon can result in a sudden rise in temperature, leading to the breakdown of insulation materials and ultimately to failure or explosion of the transformer. Regular inspections and maintenance are essential to detect and correct interturn short circuits before they lead to serious issues.

Cooling System Failures

The cooling system of a transformer is designed to maintain optimal operating temperatures by dissipating heat away from the core and windings. When the cooling system fails, it can lead to overheating and, consequently, failure of the transformer. Common cooling system failures include blocked cooling channels, leaks, and mechanical issues with fans or pumps. Ensuring regular maintenance and inspection of the cooling system can help prevent these types of failures.

Failure of Protection Relays

Protection relays play a crucial role in transformer safety by monitoring various parameters and triggering alarms or tripping the transformer if a fault is detected. However, if these relays fail to function properly, the transformer can be exposed to risks that could lead to failure or explosion. A common issue is the failure of Buchholz relays to issue alarm or tripping signals in the event of pressure build-up or other issues. Regular testing and maintenance of these relays are essential to ensure their reliability.

Other Contributing Factors

Mismanagement during manufacturing, the use of poor-quality materials like core, oil, and copper, poor maintenance, overloading, imbalanced loading, lightning strikes, surges, maintenance or operations of tap changers, and overheating of coils or cores due to a failure of the cooling system are all contributors to transformer failure. Mismanagement during manufacturing can lead to design flaws or substandard materials, while poor maintenance can exacerbate existing issues. Overloading and lightning strikes can cause rapid temperature increases and physical damage, while imbalanced loading can lead to uneven distribution of heat and stress.

In conclusion, transformer failure and explosion are complex issues influenced by various factors. Effective preventive maintenance, regular inspections, and the use of high-quality materials are critical to maintaining transformer reliability and safety. By understanding and addressing these common causes, we can significantly reduce the risk of transformer failures and ensure the continued safe operation of electrical systems.