Comprehensive reliability assessment of smart distribution networks considering centralized distribution protection system

The protection system has important influences on the reliability of smart distribution networks. Therefore, the comprehensive reliability assessment of smart distribution networks includes primary distribution networks and a protection system. Because the traditional reliability evaluation of a distribution network does not consider the influence of relay protection and the complex configuration mode of the area-centralized distribution protection system (ACDPS) in the smart distribution network, a comprehensive reliability analysis method was proposed in this article. First, the whole reliability model of the area-centralized protection system, including two major failure modes, is proposed based on the fault tree method. Then, an equivalent model of the area-centralized protection system in circuit breakers or switches for the undesired-tripping mode and the fail-to-operate mode is also established. Based on this, an improved failure mode and effect analysis (IFMEA) method is presented to assess the comprehensive reliability of smart distribution networks considering the influence of fault location and protection system. The proposed method can correctly evaluate the comprehensive reliability of the smart distribution networks. The research results are also helpful to the construction of a protection system in the smart distribution networks. (c) 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.