Affiliations: [a] State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, China | [b] Hebei Province Key Laboratory of EFEAR (Hebei University of Technology), Tianjin, China | [c] Hebei Provincial Key Laboratory of Electromagnetic & Structural Performance of Power Transmission and Transformation Equipment, Baoding, China
Correspondence:
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Corresponding author: Changgeng Zhang, Hebei Province Key Laboratory of EFEAR (Hebei University of Technology), Tianjin 300130, China. E-mail: changgeng.zhang@hebut.edu.cn
Abstract: A 3-D coupled magneto-fluid-thermal model is established for temperature rise prediction in a ventilated dry-type transformer rated at 2500 kVA. In order to accurately estimate electromagnetic losses, a three-dimensional (3-D) transient finite element method considering the effect of eddy-current losses on the foil type windings is proposed. Besides, two orthogonal B-P loss curves are adopted to model the anisotropy of grain-oriented (GO) silicon steel. The non-uniform power losses of winding and core are mapped into the thermal field as heat sources. Moreover, the transformer structures such as the narrow struts, insulation barrier and clamps are considered to improve the computational accuracy of air velocity and temperature distribution. At last, the test of temperature rise has been carried out to verify the proposed model.
Keywords: Dry-type transformer, eddy currents, power losses, magnetic measurements
