Research On Line Loss And Comprehensive Energy-Saving Technology Of Active Distribution Network In Alpine Region

At a time when the "carbon peaking and carbon neutrality goals" is being pursued,environmental and economic indicators are increasingly becoming one of the main factors for the operation efficiency of distribution network.The comprehensive energy-saving technology can solve the problems of efficient power utilization and loss reduction in active distribution network.Moreover,the calculation of distribution network in alpine regions often ignores the influence of temperature factors and leads an errors results in the current study.Therefore,this paper proposes a comprehensive energy-saving and loss reduction technology for distribution networks in alpine regions based on the active control of various devices in the distribution network and considering the influence of climate characteristics on the calculation of line loss.The main research achievements are as follows:Firstly,loss reduction methods for distribution networks in alpine regions are proposed as a basis for the comprehensive energy-saving technology.The first point is based on the thermal-resistance model of electrical components,which analyses the influence of ambient temperature on the operating temperature and hence the change in line loss calculation,and expands power flow calculation method with temperature variable.The second point analyses the correlation between the factors cause of line loss based on PLS and Pearson correlation coefficients,and selects the supply radius and power transmission as indicators to obtain a clustering model for feeders based on the optimal fuzzy-c mean clustering method.On this basis,the loss caused by three-phase imbalance and reactive power deficit are further reduced by using load switching and dynamic reactive power compensation methods for the high-loss feeders in the aggregation.Secondly,in response to the current situation of large-scale access to distributed generation in China’s distribution network,an energy-saving optimization method for DG in the active distribution network is proposed.From the planning perspective,a multi-objective function is constructed considering the life cycle and carbon trading cost of DG,and the optimal solution of its siting and sizing is determined by particle swarm algorithm.In the operational perspective,an economic early-warning model is established considering the optimal economic operation time of DG,and different reward and punishment coefficients are defined through the model to modify their contribution to line loss allocation in order to reflect the requirements of the current economic incentive mechanism of the electricity market.Finally,a closed-loop line loss control model is proposed for distribution networks in alpine regions,applying the idea of hierarchical control.The first step of the model evaluates the maximum loss reduction space,identifies the locations of high loss feeders and controls the actions of three types of equipment from the perspective of day-ahead reconfiguration.In the second step,DG are connected to the network according to the optimal planning results,and the results of the first step are used as the initial state of the distribution network structure for each time period,with the lowest line loss and optimal economy as the objective to output the economic dispatch results of the active load-side response of DG,energy storage and electric vehicle charging piles.In the third step,phase change switches,FACTS and energy storage units are selected for control to obtain the results of local high loss,and the overall loss reduction is compared with the predicted value to output the evaluation of user satisfaction and realize the closed-loop control of line loss.In summary,this paper makes full use of the control technology of each component in the distribution network to form a complete line loss identification and management model,realizing a closed-loop control of energy-saving in active distribution networks,which is of great significance to the economy,stability and development planning of distribution network operation in alpine regions of China.