RELIABILITY ASSESSMENT FOR THE BOOST-CONVERTER OF A SOLAR SYSTEM IN A DIRECT CURRENT MICROGRID

Abstract

A direct current microgrid commonly takes power from solar systems and battery energy storage when disconnecting from the main grid. Accordingly, the dynamic or transient operation of the solar system can impact the reliability of the solar system’s boost converters. This research proposes a methodology to assess the reliability of those boost-converters under dynamic and fault conditions. To conduct the reliability analysis, we will formulate the dynamic-voltage-based failure rate and short-circuit-current-based failure rate for the solar system’s boost converter. More explicitly, the evaluation of the reliability of both the solar system’s boost converter and each component relies on a novel amalgamation of the used-time-dependent failure rate, dynamic-voltage-based failure rate, and short-circuit-current-based failure rate, coupled with the utilization of a Markov-state transition methodology. The repeated occurrence of dynamic cases within the islanded direct current microgrid can significantly diminish the reliability of the solar system’s boost converter. Furthermore, the dynamic and transient cases in the LVDC microgrid can swiftly diminish two key indices: mean-time-to-failure and mean-time-between-failures of the solar system’s boost converter.