4250 kVA급 ONAN 변압기의 구조건전성과 냉각 성능 평가

Abstract

The main research content of this paper is to evaluate the structural integrity and cooling performance of 4250 kVA power transformer with ONAN mode. In terms of structural integrity evaluation, static and dynamic analysis method is used to calculate the static analysis of transformer for safety under operating conditions and the seismic analysis of the transformer. The transformer structure is simplified for analysis, NX software is used to build a three-dimensional model, and use ANSYS commercial software is used to simulate and calculate by applying corresponding load forces to different parts of the model to obtain the stress distribution of each part of the transformer, and IEEE Std. 693 standard is applied to verify that the seismic performance of the transformer meets the design requirements. In addition, the seismic analysis was simulated by using a solid element and a shell element in consideration of the element characteristics, and each result value and the simulation process were compared. In terms of cooling performance analysis, using the IEC std. 693-2018 thermal model, the hot spot temperature and top oil temperature of the transformer were calculated. The heat transfer generated from the radiator of the transformer can be numerically calculated and the cooling performance of the radiator can be checked using the reduced model. Also The boundary condition values inside the transformer is calculated, and the results of the IEC thermal model is compared with the insulating oil inlet temperature, which is the top oil temperature, to obtain only 1.26% error.