A qualified dry-type transformer under the combined seismic conditions

This article presents the design, seismic simulation, and seismic testing of a 2500 kVA 36 kV 7.7-ton dry-type transformer designed to withstand the rigorous IEEE693-2018 moderate-level seismic test involving dynamic forces in the range of 0-55 Hz and 0.5 g acceleration. The testing was conducted at IAGB Test Company in Munich, Germany, and we are pleased to report that the test was successfully completed. Remarkably, the transformer design eliminates the need for additional consoles or supports, achieving stability solely through the use of eight M24 fasteners for secure grounding. This innovative approach ensures the transformer’s resilience under seismic conditions, addressing critical considerations for power infrastructure in earthquake-prone regions. The results and implications of this seismic testing contribute valuable insights to the field of transformer design and seismic resilience

Investigation of magnetic wall shunt combinations on 650 MVA power transformers by finite element methods

Power transformer losses mainly include open circuit loss and short circuit loss. Open circuit loss is created in the iron core of the transformer. Short circuit loss, copper loss, and stray loss are known collectively as “short circuit loss”. Copper loss is created in windings: current flows through the DC resistance in windings. Stray loss is caused by eddy currents in high magnetic permeability and high conductivity of components such as tanks, windings, and structural parts. This is why the volume limit of power transformers and the ratio of stray loss in structural parts and the tank cannot be ignored. This has led transformer manufacturers to add magnetic wall shunts to reduce stray loss. But often, too many magnetic wall shunts are added or misplaced, which results in increased cost and reduced performance. By improving stray loss distribution in power transformers, magnetic wall shunt design can be optimized, and the tradeoff of cost and performance can be balanced