Reconstructed Phase Current-Based Fault Diagnosis Method for Interleaved Buck Converter

The interleaved converter is widely used in clean energy systems due to inherent advantages, such as low current ripple, high reliability, and superior energy density. However, an open circuit fault (OCF) will increase the current ripple and reduce the reliability of an interleaved converter. Therefore, detecting and locating the OCF as soon as possible is essential. This paper proposes a robust method based on the reconstructed phase current to detect and locate the OCF. The phase current averages are reconstructed by establishing mathematical relationships between total input current and phase currents. The reconstructed phase currents can easily indicate the fault phase. Instead of requiring N sensors to sample the phase current, only a single current sensor is necessary for input current sampling. Additionally, the reconstructed phase current can also be used for current-sharing control, offering cost-effectiveness. Both simulation and hardware experiments confirm the effectiveness and robustness of the proposed method. The proposed method quickly diagnoses the OCF within a switching period in hardware experiments. Furthermore, the robustness of the proposed method against input voltage and load disturbances and its operation at higher switching frequencies are demonstrated. Notably, the proposed method is adaptable to multi-phase interleaved buck converter, regardless of the number of phases.