Abstract:
A power amplifier is used to supply sinusoidal currents of different frequencies for measuring eddy-current losses of a 25 kVA single-phase transformer under short-circui...Show MoreMetadata
Abstract:
A power amplifier is used to supply sinusoidal currents of different frequencies for measuring eddy-current losses of a 25 kVA single-phase transformer under short-circuit condition. Measured data show that eddy-current loss is a linear function of frequency with power of 2 and the eddy-current loss coefficient P/sub EC-Rlinear/ is computed. New measurement techniques are applied to determine the derating of single-phase transformers with full-wave diode and thyristor rectifier loads. The derating of transformers has been defined such that for the (apparent, real) power transfer of a transformer the total losses are identical to the rated losses at rated temperature. A relation between apparent power, derating and K-factor is given taking into account iron-core and stray-power losses. Measured derating values are compared with computed results based on the eddy-current losses, iron-core losses, stray-power losses, and K-factors. The eddy-current loss coefficient P/sub EC-Rnonlinear/ is computed from harmonics caused by diode/thyristor bridge loads.
Published in: IEEE Transactions on Power Delivery ( Volume: 15, Issue: 1, January 2000)
DOI: 10.1109/61.847243
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