Abstract: In order to speed up the risk assessment of power outages in the distribution network and reduce the losses caused by natural disasters to the distribution system and users, this paper proposes an assessment of power outage risk of distribution network based on accident tree screening. After the occurrence of the disaster, the accident tree was used to screen the assessment area, and the power outage risk under the influence of the disaster was calculated by using the proposed power outage risk assessment method. In view of the fact that the implementation of certain emergency remedial measures according to the assessment results before the disaster can reduce the load affected by the disaster, the measures such as using the transfer of supply, starting the self-provided power supply and the emergency power supply are proposed to reduce the load affected by the disaster. Through the analysis of examples, it is concluded that this method can quickly evaluate the risk value of the system affected by disasters, and can reduce the risk value of disaster impact by implementing corresponding remedial measures in advance, which has certain application value.

    Key words: distribution network; risk assessment; outage; fault tree screening