Harmonic Impact on Distribution Transformer No-Load Loss

The losses in European Union distribution transformers are estimated at about 33 TW ·h/year, whereas reactive power and harmonic losses add a further 5 TW ·h/year. The reduction of distribution transformer no-load loss is particularly important as the ratio of no-load to load losses is nearly three. In this paper, the no-load operation of wound-core transformers under sinusoidal and distorted supply-voltage conditions is investigated. For that purpose, a 2-D nonlinear transient finite-element analysis taking into account hysteresis has been developed. The hysteresis model is based on a modified Jiles-Atherton representation, and the proposed analysis is compared to experimental data.