Frequency Domain Diagnostics of Transformer Insulation

Abstract

The first part of paper deals with the base information about diagnostics of power transformers. In this part are presented differently insulating methods, for example method of recovery voltage method, method of polarization and depolarization currents and chromatographic analysis.The second part of paper deals use of method of frequency domain spectroscopy for oil power transformers. This method is used in analysis insulating condition of power transformer with system of oil-paper. It was found, that the results of these tests are highly impacted by the operating temperature during the experimental measurement. Moisture and conductivity between insulating paper and oil in an insulating system are highly dependent from temperature.In the other part, the paper presents experimental results of the frequency diagnostic measurement for a real single-phase traction transformer 110/27 kV at different operating temperatures and states (with oil and without).Finally in the last part, the paper presents comparing frequency insulating measurements among several the same single-phase transformers 110/27 kV.

Development of a simulation model for assessing the technical condition of the magnetic circuit of oil power transformers by measuring the temperature of the tank and the external environment

“…Due to the high cost of the housings, it is impossible to replace them with new ones, but you can extend the operating time [1][2]6]. Therefore, diagnostics of oil-immersed power transformers should be considered an integral part of ensuring the reliability and long-term operation of electrical power systems [7][8][9][10][11]. This practice makes it possible to effectively manage resources and ensure a stable energy supply, which ultimately has a positive effect on the economy and reliability of the energy infrastructure [9,[12][13].…”

“…This practice makes it possible to effectively manage resources and ensure a stable energy supply, which ultimately has a positive effect on the economy and reliability of the energy infrastructure [9,[12][13]. Replacing or repairing a transformer requires significant financial and time costs [6][7][8][9][10][11][12]. Diagnostics allows you to optimize costs and extend the service life of equipment [7,[14][15][16].…”

“…Diagnostics allows you to optimize costs and extend the service life of equipment [7,[14][15][16]. Regularly checking the condition of the transformer helps prevent loss of efficiency due to insulation problems or other defects [4,[8][9][17][18][19][20]. Compliance with codes and standards Many countries have strict regulations for the maintenance and diagnosis of electrical equipment [9-10, 15, 19-23].…”

Development of a simulation model for assessing the technical condition of oil power transformers by measuring vibroacoustic parameters

“…Diagnostics of oil-based power transformers is an integral part of ensuring the reliability and safety of electric power systems [1][2][3]. This avoids serious failures and emergencies, ensures uninterrupted power supply and reduces risks to personnel and the environment [4][5][6][7].…”

Investigation of factors influencing the operational characteristics of traction transformers

“…).The uninterrupted and trouble-free operation of electric trains depends on the condition of the traction transformers [1,5,6]. Analysis of literature sources shows that [7][8][9][10][11][12][13][14][15][16] during the operation of transformers, malfunctions can be observed in the form of failure of the magnetic circuit, insulation failure, faults at the output of the transformer, oil leakage, cracks inside the transformer, excess of the permissible oil temperature, violations of oil circulation, loss of dielectric properties of oil, cracks in the rods, transformer operation with noise. [2,3,[17][18][19][20][21].…”