Improvement Method Of Equipment Utilization Efficiency For Distribution Network Considering Flexible Load

As the carrier of power distribution,the distribution network has a large proportion of the number of electrical equipment.If we can improve the equipment utilization efficiency of distribution network(EUEDN)under the condition of ensuring power supply reliability and operational safety,it can not only save the investment in the distribution network,but also improve t he economy of the electric power company.Improve the utilization of resources and respond to the call for energy conservation and emission reduction.Compared with developed countries,the level of EUEDN in China is under-developed.The problem of low EUEDN is especially outstanding.With the development of intelligent power technology,the flexible characteristics of user-side loads are gradually presented.Large-scale access of flexible loads has a variety of effects on EUEDN.It also provides a new way to improve EUEDN.In allusion to the above problems,this article mainly includes the following contents:The influence of flexible load on EUEDN is quantified.Firstly,the response characteristic model,compensation cost model and economic dispatch model of flexible load are established.Then the EUEDN evaluation index is divided into two categories,which is able to evaluate the impact of flexible load on EUEDN and unable to evaluate.Burden rate,capacity-load ratio and load rate are selected as the EUEDN evaluation index in this paper.Based on the influencing factors of each index,this paper analyses how the flexible load affects each index and quantifies its impact.Finally,an example is given to verify the validity of the evaluation index and the correctness of the analysis results.It is concluded that the interaction between flexible load and power grid can improve the burden rate,reduce the load rate and improve the capacity-load ratio.Aiming at the problem that the interaction between curtailable load and power grid will reduce the utilization efficiency of substation equipment,an optimal planning method of substation capacity considering curtailable load is proposed.Firstly,the necessity and feasibility of considering the curtailable load at the planning level are demonstrated.Then an optimal planning model of substation capacity considering curtailable load and its compensation and operation cost is established.The objective function is to minimize the total cost.Considering the operatio n constraints of distribution network and the related constraints of curtailable load,the impact of curtailable load on maximum load forecasting is quantified.Finally,a case study was performed to verify the proposed model.Result demonstrate that this method can reduce the capacity-load ratio and improve the utilization efficiency of substation equipment on the premise of meeting the safe operation conditions of power grid.It can also save the planning cost of substation capacity,and has certain economic benefits.Aiming at the problem that the interaction between flexible load and power grid will affect the utilization efficiency of line,a method to improve the utilization efficiency of line considering flexible load is proposed.Firstly,two indexes that the complementarity between load and load,the matching degree between load and DG is proposed.The definition and quantification method are given respectively.Complementarity and matching degree are positively correlated with the utilization efficiency of line,thus a method of improving the two indexes with flexible loads by formulating interactive strategies is proposed.The results show that the burden rate of line increases by 8% after using flexible load to enhance complementarity degree,and 13.2% after using flexible load to enhance matching degree.In some scenarios,this method can also reduce the workload of strategy formulation and operat ion cost of power grid companies.In this paper,how to use flexible load to improve EUEDN is studied.Based on the research of the relationship between flexible load and EUEDN,from the perspective of planning,an optimal substation capacity planning method considering curtailable load is proposed.From the operational point of view,the method of using the flexible load to improve the complementarity and matching degree is proposed,which providing specific methods and recommendations for improving EUEDN.