Study of Power Transformer Mechanical Faults Detection by Using Vibrodiagnostics

13th International Conference of Young Scientists on Energy Issues: Proceedings of CYCENI 2016 2016
Jānis Mārks

Power transformers are important elements of the electrical system and have a high degree of risk since in case of failure the generator connected to the damaged transformer cannot transfer energy to electrical system. Therefore, a generated power deficit may be formed and part of the consumers can be disconnected from power supply. Power transformers can experience various types of faults that may be potentially dangerous and cause the failure of the device. Various diagnostic methods exist for the detection of these damages. Each of them designed for a specific transformer characteristic. For example, measurement of winding insulation resistance and dissolved gas analysis can be used to detect electrical faults, but thermography is used to identify thermal defects. It should be noted that these widely used methods are not intended to detect mechanical faults. However, one possible approach to detect them is based on analysis of vibration measurements on the surface of transformer tank. This method is discussed in this article. In order to detect mechanical defects, certain difficulties occur. It is impossible to see what is happening inside the transformer tank without opening it, but vibration analysis can acquire information about transformer windings and core mechanical condition without doing so. This is because vibration sensors are mounted on the transformer tank surface. Consequently, it is possible to analyse the causes of mechanical defects, their location within the transformer’s structure and their intensity while transformer is operating. A case study is provided where data is analysed from a power transformer with increased vibration levels, which is installed in a power plant in Latvia. A method is proposed for graphical analysis of the results of vibration measurements. It allows obtaining more information about vibration amplitudes, their distribution and epicentres, as well as vibration changes within a specified time period caused by the transformer.

Keywords
Power transformers, fault detection, condition monitoring

Mārks, J. Study of Power Transformer Mechanical Faults Detection by Using Vibrodiagnostics. In: 13th International Conference of Young Scientists on Energy Issues: Proceedings of CYCENI 2016, Lithuania, Kaunas, 26-27 May, 2016. Kaunas: 2016, pp.135-144. ISSN 1822-7554.

Publication language
English (en)