| Title |
Fail-Safe System Design Method for LLC Resonant Converters of Electric Vehicle LDC |
| Authors |
장진수(Jin-Su Jang) ; 임태현(Tea-Hyeon Lim) ; 손동규(Dong-Gyu Son) ; 김청훈(Chung-Hun Kim) ; 이기영(Gi-Young Lee) |
| DOI |
https://doi.org/10.5370/KIEE.2025.74.12.2501 |
| Keywords |
LLC Resonant converter; Fail-safe; LDC(Low-Voltage DC-DC Converter); Switch Fault |
| 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. |