| Title |
Open-Circuit Fault Detection Algorithm for Switches in Full Bridge LLC Resonant Converters Based on Resonant Capacitor Voltage |
| Authors |
Su-Jin Kang ; Su-Yong Chae |
| DOI |
https://doi.org/10.6113/TKPE.2026.31.1.65 |
| ISSN |
1229-2214(pISSN), 2288-6281(eISSN) |
| Keywords |
LLC Resonant Converter; Open-circuit fault detection; Fault localization; Capacitor voltage |
| Abstract |
This study proposes a two-step open-circuit fault (OCF) detection and localization method for full-bridge LLC resonant converters. If a primary-side switch fault occurs, then the full-bridge LLC converter may transition into the half-bridge mode to maintain continuous operation without interruption. Under these conditions, a robust fault detection and localization method is critical. The proposed method uses only a single voltage sensor to monitor the resonant capacitor voltage (RCV). The method first detects OCFs in primary-side switches by analyzing the slope of the integral of the measured RCV signal. Then, a phase-shift modulation is applied to induce additional slope variations for the precise localization of faulty switches. The effectiveness of the proposed method is experimentally validated on a 125 W/24 V LLC converter. |