Urban Distribution Network Risk Assessment And Application Based On Adverse Weather Condition

Recently frequent natural disasters have happened worldwide. Improving emergency response capacity of urban distribution network is the key to reducing the impact of accidents on the economy and society.Traditional reliability assessment aims at the probability of accidents, ignoring the consequences caused by accidents. The proposed risk indicators do not have a clear physical meaning, cannot compare the risk of distribution network in different conditions. To solve these problems, this paper studies the risk assessment of urban distribution under harsh climatic conditions, considering three basic elements:the external (environment, climate, etc.), the internal (topology, load distribution, the trend level, equipment service time, etc.) and service objects (power load).In terms of object empowerment, this paper proposes an improved objective and subjective right moment method based on the estimated weight of the integrated assignment methods. By the subjective and objective method we can obtain the weight value of each load, then construct an optimization model based on moment estimation, finally obtain the weight value of each load.In terms of device modeling, this paper establishes a short-term outage equipment model based on real-time operating mode and external climate conditions. This model consists of two parts:aging outage model and occasional outage model. For the aging characteristics of transformers and distribution lines, the aging outage model introduces new variables such as temperature. Through the quantitative calculation of wind loads and ice loads, the occasional outage model obtains the occasional device outage probability under the corresponding climatic conditions.In terms of distribution network outage risk calculations, this paper proposes a risk assessment method of urban distribution network under disaster based on minimum over-heated region. By analyzing the outage probability of relevant minimum over-heated region under various disasters, calculate the outage risk value of loads and apply it as a criterion for timely early warning and plans. This paper takes the self-healing control of distribution network into consideration, overcomes the conservative calculation of traditional risk assessment; significantly enhances the computing speed while quantifies the power loss to compare the extent of damage under different operational states.