Accuracy of testing equipment: If the testing instruments used, such as thermometers, voltmeters, ammeters, insulation resistance testers, etc., have insufficient accuracy or inaccurate calibration, it can lead to measurement data errors, thereby affecting the judgment of faults.

Operator experience and skills: The familiarity and practical experience of operators with the working principle, structure, and common types of faults of transformers will directly affect the accuracy of judgment. Lack of experience may lead to neglect or misjudgment of abnormal phenomena.

Environmental factors: The temperature, humidity, electromagnetic field interference, and other factors in the surrounding environment may affect the performance and measurement results of the detection equipment. For example, high temperature and high humidity environments may result in low insulation resistance measurements.

Transformer operating history and load conditions: Without understanding the past operating conditions of the transformer, such as whether it has been subjected to overvoltage or overcurrent surges, as well as the current load type and load changes, it may be difficult to accurately determine the cause of the current fault.

The complexity and concealment of faults: Some faults may be the result of multiple factors working together, or the fault points may be relatively hidden and difficult to detect and detect.

Integrity of data recording and analysis: Failure to fully and accurately record the operational data and test results of transformers, or improper methods in data analysis, can affect the accuracy of fault diagnosis.

For example, a transformer experienced a slight increase in oil temperature, which was mistakenly identified as an internal fault due to the operator’s failure to fully consider the high ambient temperature at the time; For example, for a transformer that has been operating under overload for a long time, without understanding its load history, it may be difficult to accurately determine whether the fault is caused by long-term overload or other sudden reasons.

In short, to improve the accuracy of transformer fault diagnosis, it is necessary to comprehensively consider the above factors and take effective measures to reduce their adverse effects.