Fault Tolerant Topology and Diagnostic Strategy for LLC Resonant Converters

This study introduce a fault-tolerant topology specifically designed to address switch failures. This topology ensures that, even in the event of a switch failure, the LLC converter maintains a consistent output voltage and continues to operate near its resonant frequency, thereby preserving system performance. The proposed topology achieves fault tolerance through a reconfiguration mechanism that isolates the faulty switch and redistributes the operational roles among the remaining components, minimizing disruption to the converter’s functionality. Additionally, we propose a resonant capacitor voltage-based fault diagnosis method. This method enables rapid detection and isolation of faults within a single switching cycle, significantly reducing the response time compared to traditional fault diagnosis approaches. The diagnostic process involves real-time monitoring of the resonant capacitor voltage, allowing for immediate identification of anomalies indicative of switch failures. To validate the effectiveness of the proposed fault-tolerant topology and diagnostic strategy, we conducted comprehensive simulation experiments. The results demonstrate that the LLC converter, equipped with the proposed solutions, successfully maintains stable output voltage and operates near the resonant frequency even after experiencing switch failures.