Low Voltage Impulse Testing (LVI) on transformers can be used to detect winding movement, such as caused by short circuits or by loss of winding clamping pressure. The technique is being developed to do tests with transformers on- line. The techniques are described and results presented.
Wang, M., & Vandermaar, A. J. (1999). CONDITION MONITORING OF TRANSFORMERS IN SERVICE BY THE LOW VOLTAGE IMPULSE TEST METHOD. Engineering, (467), 45–48. https://doi.org/10.1049/cp:19990504