Development of the new generation of high power and high frequency power electronic switches along with the need for compact controllable converters for utilization of distributed energy resources in the grid, have led to significant developments in the area of solid state transformers in the last years. The design process of a high frequency transformer as the main element in the solid state transformer is illustrated in this article. A multi winding transformer for multiport SST application is designed, studied and built in this research. In a MPSST several windings feed the core. As the result, coupling coefficient between each pair of windings, become an important factor which is studied in this study. Since the transformer is designed for high frequency applications, the power loss in the wire and core of the transformer increases as the result of higher skin effect and eddy current loss in high frequency. Three important factors in the design of HF transformer for MPSST are discussed in the paper. First, four different possible core materials are compared based on their flux density, frequency range, loss and price. Then the cable selection is illustrated and finally, different winding placement and distribution on the same core are suggested and the inductance and coupling coefficient matrices are calculated using ANSYS Maxwell 3D simulation. The transformer is built in the lab and the inductance values matches the expected values from the simulation.
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A High Power High Frequency Transformer Design for Solid State Transformer Applications
In this study, design of a 330kW single-phase transformer (corresponding to 1MW three-phase) operating at 50kHz is presented. Possible core materials and their performances are investigated under high switching frequency operation. Core volume, area, configuration, and market availability are studied to achieve the optimal compact and cost-effective transformer model. Next, transformer winding type, size, placement, and cost are analyzed. These steps will result in a complete transformer electromagnetic design and modelling. Afterwards, a 3D transformer model is created and simulated using a Finite Element Analysis (FEA) tool. ANSYS Maxwell-3D is used to simulate the magnetics, electrostatics, and transients of the designed transformer. This model is integrated with a power electronics circuit in ANSYS Simplorer to make a co-simulation for the entire system. Results obtained will include core maximum flux density, core/copper losses, leakage/magnetizing inductances, windings parasitic capacitances, and input/output voltage, current, and power values. Finally, the systems' overall efficiency is calculated and presented.
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- Award ID(s):
- 1650470
- NSF-PAR ID:
- 10223263
- Date Published:
- Journal Name:
- 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA)
- Page Range / eLocation ID:
- 904 to 909
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/ICRERA47325.2019.8996515
