https://scholarworks.gnu.ac.kr/handle/sw.gnu/490 2026-03-14T05:45:29Z 2026-03-14T05:45:29Z Ha, Jonghyeon Suh, Minki Ryu, Minsang Lee, Dabok Jeon, Dae-Young Kim, Jungsik https://scholarworks.gnu.ac.kr/handle/sw.gnu/81325 2026-01-29T06:30:32Z 2026-01-01T00:00:00Z

Title: Radiation effect in FD-SOI nanowire FETs due to high dose rate gamma-ray under variable irradiation temperatures Authors: Ha, Jonghyeon; Suh, Minki; Ryu, Minsang; Lee, Dabok; Jeon, Dae-Young; Kim, Jungsik Abstract: In this study, the effects of gamma-ray irradiation on fully depleted silicon on insulator (FD-SOI) Nanowire FETs (NWFETs) at different irradiation temperatures (265, 300, and 400 K) were analyzed. For PMOS, positive threshold shift (dVth) owing to interface and oxide traps could be observed regardless of the irradiation temperature. However, NMOS showed a different temperature trend. At 400 K, the oxide traps were cured during annealing, enhancing the influence of interface traps and resulting in a positive dVth. In comparison, at 265 K, the oxide traps became more influential due to reduced hole mobility in the buried oxide (BOX), resulting in a negative dVth. Annealing was performed at room temperature for 24 and 168 h to investigate the dVth owing to the annealing effect (dVth-anneal). In NMOS, a positive dVth-anneal occurred regardless of width (W) as the oxide traps were cured by annealing. PMOS showed a negative dVth-anneal regardless of W.

2026-01-01T00:00:00Z Lim, Tae-Hyeon Jang, Jin-Su Lee, Gi-Young https://scholarworks.gnu.ac.kr/handle/sw.gnu/82331 2026-02-09T05:30:19Z 2026-01-01T00:00:00Z

Title: Modeling and Control Gain Design Method for Dual Active Bridge Converter with Dual-Phase-Shift Modulation Authors: Lim, Tae-Hyeon; Jang, Jin-Su; Lee, Gi-Young Abstract: The Dual Active Bridge (DAB) converter offers several advantages, including high power conversion efficiency and improved safety by providing galvanic isolation between the input and output through the use of a high-frequency transformer and H-bridge circuits on both the primary and secondary sides. Although numerous studies have explored DAB converters, research on transfer function modeling under Dual Phase Shift (DPS) modulation and its correlation with controller gain design based on converter parameters remains limited. This paper proposes a modeling approach for a DAB converter with DPS modulation and presents a parameter-based gain design method for a voltage-current double-loop controller. The dynamic characteristics of the DAB converter are derived using generalized average modeling (GAM) based on Fourier transformation. The derived transfer function is simplified based on the locations of its poles and zeros. Based on this simplification, a systematic procedure for proportional-integral (PI) controller gain design is formulated for both output voltage and current regulation. The validity of the simplified transfer functions is verified through Bode plot analysis. The validity and effectiveness of the proposed control gain design method are verified through a hardware-in-the-loop simulation (HILS) capable of emulating a virtual DAB converter. Through this experiment, both the steady-state and transient responses of the virtually implemented DPS-modulated DAB converter are evaluated. The results validate the effectiveness of the proposed approach in achieving stable DPS modulation and control in DAB converters.

2026-01-01T00:00:00Z 장진수 임태현 손동규 김청훈 이기영 https://scholarworks.gnu.ac.kr/handle/sw.gnu/81403 2026-03-03T01:30:23Z 2025-12-01T00:00:00Z

Title: 전기차 LDC용 LLC 공진형 컨버터의 Fail-Safe 시스템 설계 방법 Authors: 장진수; 임태현; 손동규; 김청훈; 이기영 Abstract: This paper proposes a fail-safe compensation circuit design method that allows an LLC resonant converter for mobility applications to maintain normal operation for a certain period even in the event of a switch Failure. In the proposed fail-safe system, when a switch fault occurs during full-bridge operation, the converter transitions to half-bridge operation to suppress unwanted voltage spikes caused by pole voltages. To compensate for the voltage drop resulting from the halved resonant tank input voltage, an additional fail-safe capacitor is connected in parallel with the existing resonant capacitor, and a semiconductor switch is used to form the parallel circuit upon switch Failure. As a result, the resonant tank voltage gain can be adjusted through the modified resonant tank parameters. This study also presents a capacitance determination method for fail-safe operation and verifies its effectiveness through PSIM simulations.

2025-12-01T00:00:00Z Lim, Tae-Hyeon Jang, Jin-Su Kim, Tae Heoung Min, Sung-Soo Lee, Gi-Young https://scholarworks.gnu.ac.kr/handle/sw.gnu/79741 2026-01-08T11:00:56Z 2025-11-01T00:00:00Z

Title: A Parameter-Based Design Methodology for Double-Loop Control of Dual Active Bridge Converters Authors: Lim, Tae-Hyeon; Jang, Jin-Su; Kim, Tae Heoung; Min, Sung-Soo; Lee, Gi-Young Abstract: The dual active bridge (DAB) converter is widely used in bidirectional power conversion applications due to its high efficiency, power density, and galvanic isolation. Although there have been many studies on the modeling of DAB converters, research on the impact of parameters on control gain design is still limited. This paper presents a parameter-based design methodology for the double-loop control of DAB converters. Small-signal models for voltage and current control loops are derived using generalized average modeling, with transfer function coefficients expressed in terms of DAB parameters. Through dominant pole analysis and low-frequency approximation, the transfer functions are simplified to allow intuitive proportional-integral (PI) gain design. The proposed method enables systematic gain tuning based on parameters such as rated power, transformer characteristics, and control bandwidths, without complex numerical procedures. Bode plot analysis confirms that the simplified model accurately represents the system dynamics in the low-frequency region. To validate control performance, the designed gains are implemented on a hardware-in-the-loop simulation (HILS) environment. Steady-state and transient experiments under varying load conditions verify that the proposed method achieves stable regulation and adjustable dynamic response. The results demonstrate that the proposed method enables accurate and stable double-loop control based on parameter values, while significantly simplifying the gain design process for DAB converters.

2025-11-01T00:00:00Z