A Lightweight Optimization Study for Large Capacity Dry-Type On-board Traction Transformer of EMU Based on CFD and RSM
Shuai Yuan, Lijun Zhou, Fenglin Cai, Dongyang Wang, Lujia Wang, Lin Huang
Abstract
Using the dry-type on-board traction transformer (OBTT) cooled by train-induced wind is an effective way to realize the lightweight of on-board equipment. However, the existing small capacity fan-cooled dry-type OBTT (D-OBTT) cannot meet the power requirements of the high-speed electric multiple units. For the large capacity D-OBTT, the lack of mathematical models that can reflect the relationship between hotspot temperature and design parameters limits its development. This article aims to propose an optimization method for large capacity D-OBTT. First, the user-defined function-based computational fluid dynamics modeling method for D-OBTT is proposed and validated to accurately obtain the winding hotspot temperature. Then, the response surface models of winding hotspot temperature are first proposed based on the response surface methodology. Finally, the lightweight optimization of a 6.3-MVA D-OBTT is completed, and the influence of design parameters on weight reduction is studied. Under the conservative optimization strategy, the total weight of D-OBTT is reduced to 3650.40 kg, which is reduced by 38.55% compared with the oil-cooled OBTT with the same rated capacity. This article provides an efficient and feasible method, and regular guidance for the lightweight optimal design of D-OBTT, and the obtained response surface models can be used for the optimization of similar D-OBTT under different specific needs.