An Advanced Switch Failure Diagnosis Method and Fault Tolerant Strategy in Photovoltaic Boost Converter

The PV systems have increasingly displayed remarkable usefulness and interest, particularly in a wide range of industrial applications, such as industrial control systems, medical applications and hybrid vehicles. Due to the necessity of systems continuity requirement imposed by these applications, a special careful consideration should be granted to the boost converter reliability performance. Indeed, the boost converter reliability could be affected by a faulty operation essentially related to semiconductor switch used. In this respect, this paper proposes an advanced fast FDM with a FT strategy applied in boost converter PV systems in order to guarantee their continuity. By implementing the FDM and FT strategies on a dSpace real-time system, both types of OCF and SCF in boost converter switch are detected, identified and compensated. The proposed FDM is founded on the signals variations (increase or decrease) of the PV current, voltage and power as well as the duty cycle of the PV system. Accordingly, the PV system cost and complexity dimensions should tend to decrease due to the particular use of current and voltage sensors, dedicated to maintain the systems effective control. Additionally, for the purpose of the FT strategy which is applied under a fault appearance or occurrence, a redundant switch has been incorporated into the original boost converter in order to compensate the fault. Finally, the experimental results prove to confirm the high performance and capability of the proposed FDM and FT strategy in maintaining the PV system continuity.