■ FUNDAMENTAL PRINCIPLE
Electromagnetics is a branch of physics that explores the electric and magnetic phenomena. Maxwell's equations are a set of partial differential equations that describe the electromagnetic phenomena: how electric and magnetic fields are generated, propagated, and interacted by each other and are influenced by objects. This principle can be used to determine the optimal design for the electromagnetic systems such as wireless power transfer (WPT) systems, electric motors, and inductors.
■ RESEARCH OVERVIEW
- Application area
- Optimization scheme
The goal of this research group is to develop size/shape/topology optimization methods for the electromagnetic systems and to apply them to the real-world systems ranging from low-power to high-power systems. In order to optimize the systems, it is necessary to determine the appropriate design variables (e.g., structural dimensions and coil turns), objective function (e.g., transfer efficiency and coil mass), and constraint functions (e.g., induced voltage and EMF). In the proposed optimization framework, the optimization module determines the optimized design to extremize the objective function while satisfying all the constraints with multiple design variables. The analysis module analyses the target model based on the principles of electromagnetics. Through iterations, the design variables are updated, thereby determining the optimized design at the end of optimization.
■ AREA 1 : WIRELESS POWER TRANSFER SYSTEM
- Size and shape optimization
- An optimization framework for real-world WPT systems is developed through connecting commercial electromagnetic field analysis software and an optimization module using in-house codes. The developed design framework is experimentally validated under the same working conditions.
* S. B. Lee, S. Ahn, and I. G. Jang, “Development of the Optimization Framework for Low-Power Wireless Power Transfer Systems,” IEEE Trans. Microw. Theory Tech., vol. 63, no. 3, pp. 813-820, Mar. 2015.
- Layout (or topology) optimization
- In this research, a novel layout optimization is proposed to determine the optimal layout of the secondary coils when the primary coils are given. To develop the proposed method, the analysis module is built to evaluate electromagnetic field-related measures and coil related measures. Then, the analysis module is connected with the optimization module. As an example, a portable wireless charger is optimized to maximize the induced voltage while satisfying a mass constraint and the optimized design is validated.
* S. B. Lee and I. G. Jang, “Layout Optimization of the Secondary Coils for Wireless Power Transfer Systems,” IEEE Trans. Microw. Theory Tech. under review.
■ AREA 2 : ELECTRIC MOTORS
Switched reluctance motors (SRMs) have gained in popularity over recent years due to a number of advantages they offer. First, their rugged structure is simple and robust, and the manufacturing cost is low. Second, they have a high torque/mass ratio and high efficiency. Third, their operation is reliable even at very high speeds. Considering that SRMs have been considered as a potential candidate for various electric applications, SRMs are optimized for the diverse performances through connecting between an optimization module and the electromagnetic commercial software.