| Title |
A Study on the Minimization of Tie-plate Loss of Cast Resin Transformer using Surface Impedance Boundary Condition |
| Authors |
황성률(Hwang, Sung-Ryul) ; 신판석(Shin, Pan Seok) |
| DOI |
https://doi.org/10.5370/KIEE.2017.66.9.1334 |
| Keywords |
Surface impedance ; Boundary condition ; Tie-plate ; Stray-load loss ; Cast resin transformer |
| Abstract |
In this paper, a tie-plate shape is optimized by using the numerical technique to reduce the stray load loss of the tie-plate which is a mechanical structure for assembling and supporting of the transformer core. The eddy current loss of the structure is calculated by an electromagnetic field FEM program and the results are compared with 4 different shapes of tie-plates. Since the thickness of the tie-plate is very thin, and the skin depth is very small, the number of FE elements for 3-D transformer model is too big to solve. So, the surface impedance boundary condition (SIBC) is used to reduce the system matrix size and its computing time. To verify the method a 2.5 MVA 22,900/380V distribution transformer is simulated using one objective function and three design variables with some constraints. The final optimized tie-plate has three slots of 6 mm width and 23 mm gap, and the loss is reduced by 75 %. Consequently, the proposed algorithm seems to be considerably applicable to electric machinery as well as power transformer. |