How to diagnose the fault of box-type transformer?

Box-type transformer is a device that transforms and transmits the voltage in the power system. It is widely used in industrial, agricultural, commercial and residential power consumption. Due to its compact structure, easy installation and reliable operation, box-type transformer occupies an important position in the power system. However, as the operation time increases, box-type transformers may also have various faults, such as winding short circuit, insulation aging, oil immersion heating, etc. Therefore, timely fault diagnosis and processing are of great significance to ensure the safe and stable operation of the power system.

Classification of box-type transformer faults

Box-type transformer faults can be divided into two categories: external faults and internal faults. External faults mainly include damage or failure of components such as core, winding, oil tank, gasket, insulator, etc.; internal faults mainly include electrical faults such as oil immersion heating, discharge, insulation aging, short circuit, etc.

How to diagnose the fault of box-type transformer?

‌Appearance inspection‌: Determine whether there is a fault by observing the appearance of the box-type transformer. Appearance faults are manifested in deformation and oxidation of the shell, blackening and deformation of the cable plug, etc.

‌Sound judgment‌: The box-type transformer will make a specific sound during operation. If you hear an abnormal hum, chirp or sound, it may be caused by faults such as winding short circuit, induced current and suspended iron core.

‌Smell judgment‌: If the box-type transformer emits a burnt smell, it may be caused by an electrical fault, especially the high temperature generated by spark discharge causes the organic material to oxidize and decompose to produce a burnt smell. At this time, it is necessary to stop the machine immediately for inspection.

‌Temperature detection‌: Under normal conditions, if the transformer oil temperature is more than 10°C higher than usual or the temperature continues to rise with the load unchanged (when the cooling device is operating normally), it may indicate that there is an abnormality inside the transformer.

‌Electrical test‌: By using professional testing instruments, the electrical parameters of the box-type transformer are fully tested, including voltage, current, insulation resistance, etc. The electrical test can quickly and accurately determine whether the transformer has an electrical fault, and determine the specific location and cause of the fault.

Fault handling and preventive measures

1. Fault handling

According to the fault diagnosis results, take appropriate repair measures. The repair measures may include replacing damaged parts, repairing insulation damage, adjusting electrical connections, etc. When performing repair work, the operator should strictly follow the operating procedures to ensure safety and reliability.

2. Preventive measures

In order to prevent the occurrence of box-type transformer failures, the following preventive measures can be taken:

· Regularly perform maintenance and upkeep on transformers, such as cleaning, tightening, lubrication, etc.

· Strengthen the operation monitoring and data analysis of transformers, and promptly detect and handle abnormal situations.

· Improve the skills and quality of operators, and strengthen training and assessment.

· Improve transformer protection measures, such as installing lightning arresters, overcurrent protectors, etc.

As an important power equipment, the normal operation of box-type transformers has an important impact on the stability and reliability of the power system. Therefore, it is necessary to pay attention to and strengthen maintenance and management before and during use.