A Fault Diagnosis and Postfault Reconfiguration Scheme for Interleaved Boost Converter in PV-Based System

Abstract

To utilize the solar photovoltaic (PV) energy efficiently, dc–dc converters are widely used in both grid-connected and stand-alone systems. Among the various topologies, interleaved dc–dc boost converter offers the benefit of modularity, high power density, and high efficiency along with reduced input current ripple to the PV panel, thereby improving its power extraction efficiency. Open-circuit faults in any of the semiconductor switches of interleaved boost converter could lead to unequal loading on the healthy phases and increase in ripple current that reduces the extraction efficiency of the PV system. To address this issue, a new fault detection and localization scheme is proposed in this article. The proposed scheme utilizes the switching-frequency-based harmonic component for fault detection and localization. Once the fault is localized, a postfault restoration and control strategy is also proposed to ensure equal current sharing among the remaining healthy modules within their maximum current rating and minimize the input current ripple in the PV panel. Detailed simulations are carried out to show the effectiveness of the proposed approach. A laboratory prototype of the interleaved converter is built to validate the proposed approach and experimental test results are provided.