Research On Disaster Prevention Planning Of Distribution Network

In recent years,extreme weather and natural disasters have frequently occurred,which seriously endangered social security,and may cause damage to the power grid.The distribution network,as the end of the power system,assumes the task of directly supplying power to users.At this time,if the distribution network is affected by a disaster and causes a power outage,it will cause significant losses to users.The distribution network grid planning is the core of the distribution network planning.Its main task is to solve the path from the power point to the load point based on the determined power point and load of the distribution network.At the same time,in the context of urbanization in China,the current distribution network lines in many areas of China have begun to take shape.The power supply of new users in these areas is mainly achieved by accessing to existing distribution networks.This kind of planning based on the results of load forecasting and existing network facilities is called distribution network expansion planning.Therefore,in the distribution network planning stage,improving the ability of the distribution network to resist natural disasters through reasonable planning and ensure the safe and stable operation of the power grid is of great significance.Based on the above background,this paper proposes a distribution network planning method that considers the impact of natural disasters based on different scenarios of disaster prevention planning.First,this paper studies the extent of the distribution network affected by the disaster,studies the disaster risk of the distribution network and the area where the distribution network is located.A three-state weather model of the distribution network’s disaster-prone probability of power outages.Based on the historical disaster situation of each area in the distribution network,the clustering method is used to classify the disaster levels in each area of the distribution network.Paving the way for subsequent research on distribution network grid planning and active distribution network expansion planning.Then,based on the above research,given the risk levels of each area in the distribution network,a method for planning a distribution network frame that considers intermediate nodes is proposed.The line avoids areas with high disaster levels while reducing the length of the line to reduce the impact of natural disasters on the distribution network.A mathematical model of the distribution network grid planning considering the increase of intermediate nodes is established and solved to get the optimal plan.Further,in view of the current situation in China where a large number of new loads and distributed generation(DG)are connected to the distribution network each year and the current active distribution network expansion planning research does not consider the impact of extreme weather,this paper proposes an active distribution network expansion planning method that considers extreme weather.First,the impact of natural disasters on the power grid is carried out according to the three-state model of grid disasters.Quantify and determine the disaster probability of the grid line as the influencing factor in the extended planning.Then,the two-layer planning model is used to optimize the line structure of the distribution network and the location and capacity of the distributed power supply.Finally,the upper and lower models are solved using binary particle swarm optimization and particle swarm optimization,respectively.The analysis of the example shows that the proposed method can reduce the economic cost and improve the reliability of the distribution network.