Magnetic core effects on the high-frequency behavior of transformers

Nasirpour, F.; Ghaffarian Niasar, M.; Popov, M.

doi:10.1016/j.ijepes.2024.110035

Magnetic core effects on the high-frequency behavior of transformers

Title

Magnetic core effects on the high-frequency behavior of transformers

Author

Nasirpour, F. (TU Delft Intelligent Electrical Power Grids)
Ghaffarian Niasar, M. (TU Delft High Voltage Technology Group)
Popov, M. (TU Delft Intelligent Electrical Power Grids)

Date

2024

Abstract

This paper investigates the high-frequency transformer losses attributed to eddy currents in both conductors and the core. A comprehensive model of a transformer winding is presented, meticulously incorporating skin and proximity effects. The winding resistance increase due to these effects is determined by applying analytical and finite element methods. The investigation highlights that eddy current losses in the magnetic core notably increase the resistance of each winding section in low frequencies. However, the impact of these losses diminishes as the winding length approaches the voltage wavelength at high frequencies. Consequently, the net magnetomotive force and flux in the core become negligible. As a result, the high-frequency impedance characteristics are remarkably similar for windings with and without a magnetic core. These findings are substantiated through rigorous simulations and empirical measurements.

Subject

Overvoltages
Power system transients
Power transformers
Resonances

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http://resolver.tudelft.nl/uuid:688bd488-6562-49f8-ba9c-4732113a4de0

DOI

https://doi.org/10.1016/j.ijepes.2024.110035

ISSN

0142-0615

Source

International Journal of Electrical Power & Energy Systems, 159

Part of collection

Institutional Repository