Reliability Evaluation And Operating Risk Analysis Of Distribution Network Under The Background Of Intelligent Electricity Consumption

With the increasingly severe environmental pollution and energy crisis,the construction schedule of smart distribution network is being promoted,while the capacities of distributed generations such as distributed wind power and photovoltaic power are increasingly larger and larger.Meanwhile,intelligent electricity consumption technology represented by electric vehicle(EV),as an important means to realize the smart distribution network,is widely applied.All these new factors make the shortcomings of power supply reliability evaluation index systemhas appear gradually,and result in risk and uncertainties over the operation of smart distribution network.Under the background of intelligent electricity consumption,evaluation on reliability and operating risk analysis are worth to study in smart distribution network.First of all,according to the condition of EVs' connection with grid in large scale,this paper presents a calculation method for scheduling threshold considering different demands between dispatchers and users.What's more,an evaluation model on scheduling potential of EVs is built to analyse the reserve capacity under fault condition and provide data to the reliability evaluation for smart distribution network.The scheduling potential assessment results can also provide guidance for peak shaving and valley filling,which is helpful to improve reliability of smart distribution network.Second,this paper establishes an index system to evaluate demands of power utilization reliability promotion considering the new concept of power utilization reliability.Meanwhile,the traditional technique for order preference by similarity to ideal solution is improved based on absolute ideal solution theory and grey correlation degree,and a comprehensive weight method combined with analytic hierarchy process and improved en-tropy method is used to vary the index weight.Hence optimal object selection model of power utilization reliability promotion is also set up.According to the reliability evaluation result,the smart distribution network needed to be improved most are selected out.Finally,considering the uncertainty brought by distributed wind power and photovoltaic power,voltage violation strength is proposed to describe the severity of voltage violation.And voltage violation strength is used to carry out varied weight processing of voltage distribution entropy.Thus weighted voltage distribution entropy indexes for different levels including node and network are proposed to reflect the operating risk caused by the voltage violation and the uncertainty of voltage distribution,and operating risk analysis model is also established.The effectiveness of this model is verified with an example of improved IEEE 33 system.