Reliability Evaluation Of Distribution Network Based On Cloud Model Considering Time Varying Factor

Distribution network is the essential part of the electricity transportation and theelectricity distribution form transmission system to the customs。Improving the reliability ofpower supply is the goal of the electricity companies. When assessing the distributionnetwork, the statistical data is taken as the original parameters in traditional reliabilityassessment. It demands the data to be accurate and sufficient. But in fact, statistical error anddata missing will lead to reliability assessment error. In the process of assessing, the reliabilityparameters are treated as constants, which is not consistent with the actual situation. Agingand external environment would lead to change in reliability parameters. So, we mustconsider original parameter uncertainty resulted from statistical error and the characteristicthat the reliability parameters vary with time. In order to solve it, Cloud model is introducedto deal with the original parameter uncertainty, and in this model, all components includingtransformer, lines and distribution generations are variability model preformed. Simulationresults of IEEE Bus6F4proof its effectiveness and show its necessity compared with thatwithout time-vary factors, results in the form of cloud model distribution show visually withsome works practicality. The papers main work is as follows：(1)A new reliability assessment algorithm based on cloud model and reachabilityanalysis is proposed to distribution networks.Cloud model can deal with the parameter uncertainty effectively; reachability analysiscan avoid traversing the network when judging the failure consequence type. Cloud modeland reachability analysis are combined to form a new reliability assessment algorithm toassess typical system.(2)Time varying models of whole system are established.Time varying models of failure rate and wind generation power outputs are establishedbased on the proposed linear combination and error correction prediction model; time varyingmodel of photovoltaic generation power output is established based on the establishment ofsolar radiation, temperature and photovoltaic conversion efficiency; charge and dischargemodel of energy storage device is established and based on which the co-wind-photovoltaicgeneration is established.(3) A new reliability Monte Carlo assessment algorithm considering time varying factorsis proposed to distribution networks.Based on the establishment of all time varying models, a new reliability Monte Carloassessment algorithm considering time varying factors is proposed to assess IEEE RBTS bus6F4systems. (4) A new reliability assessment algorithm based on cloud model and considering timevarying factors is proposed to distribution networks.Cloud model and Monte Carlo simulation are combined, and parameter time-varyingcharacteristic is considered as well to form a reliability assessment algorithm to assess IEEERBTS Bus6F4systems.