Modeling and Optimal Design of Inductor-Integrated Three-Phase 3-D Wound Core Transformer Under SPWM Excitation

Compared with the laminated core transformer, the three-dimensional (3-D) wound core transformer(3-D-WCT) has the characteristics of symmetrical magnetic circuit and low vibration. This article focuses on the modeling and optimal design of the 3-D-WCT for isolated dc/ac application. First, based on the Jiles-Aterton model, a nonlinear magnetic circuit model of the 3-D-WCT is established to calculate the flux density and core loss accurately under SPWM excitation. A thermal network model is presented for the steady-state temperature-rise calculation of the forced-air cooled 3-D-WCT. Second, the optimal design method is carried out on the basis of the magnetic circuit and thermal network models. Based on the optimized design results, a regression analysis is performed to establish the relationship between the design variables and the performance objectives. Finally, a 75 kVA 3-D-WCT prototype is manufactured and tested in the actual inverter power supply to verify the established magnetic circuit and thermal network models. The 3-D-WCT prototype is applied to the 150 kVA inverter power supply, which contributes to achieving high power density and high efficiency of the power supply.