Optimal design of magnetic shielding plates for main-transformer in high-speed railway vehicle using design of experiment

The thermal characteristics of magnetic shielding effects were tested numerically and verified experimentally by adopting the magnetic-thermal-fluidic multiphysics analyses technique in a main-transformer for high-speed railway vehicle. Additionally, to maximize the thermal performance of magnetic shielding plates, we used the design of experiment (DOE) procedure with 4 factors in three levels. In a special transformer such as high-speed railway vehicle, the temperature rise is critical issue and designers want to predict temperature rise while the circuit is operated [1]-[2]. Unlike other power transformer, these kinds of transformer for high-speed railway vehicle have very short distance between magnetic coils and housing. The temperature, therefore, can be significantly increased at the housing. To avoid this unwanted temperature rise, the magnetic shielding plates were proposed to be inserted between coils and housing, and the temperature rise was satisfied with a guideline in experiments. To analyze these thermal characteristics of magnetic shielding effects, we also developed the magnetic-thermal-fluidic multiphysics analysis. Figs. 1(a) and 1(b) show the distributions of temperature on the housing with and without the magnetic shielding plates and Figs. 1(c) and 1(d), on the magnetic shielding plates. And the maximum temperatures at each part were summarized in Table I. As we can see these results, the temperature was dramatically decreased with magnetic shielding plates and we might know that the shielding plates cover the heat burden in this advanced structure. In an extended paper, we will discuss the shielding effects resulting from the multidisciplinary optimization.