Research On Spatiotemporal Distribution Characteristics Of Feeder Load Of Medium And Low Voltage Distribution Network

In recent years,the development of agricultural modernization in rural areas makes a substantial increase in electricity equipment,low and medium voltage distribution network power supply capacity cannot adapt to the growing demand for electricity,resulting in low and medium distribution network operation problems,the low voltage problem is particularly prominent.The voltage of bus line of the low and medium distribution network is mainly controlled by the superior power grid,which is rarely affected by the regional load changes;whereas the voltage of feeder line of the low and medium distribution network is different,it is affected comprehensively by the geographical location and the rules of the change of the load time,and the voltage along the feeder changes greater.At present,research on the influence of the distribution network of the load classification by substation side has obtained a good effect,but research on the influence of feeder with the change of the load classification by transformers is relatively less.This essay has researched on the present situation of medium-low voltage distribution network in Xishuangbanna.The voltage monitoring data and power monitoring data has been collected in "four-in-one" measurement automation system,and the author researched on the problems in medium-low voltage distribution network.Setting low voltage problems of medium-low voltage distribution network in Xishuangbanna as an example,the author has combed and analyzed the data collected from monitoring sites of each lines.And the author has summarized the major areas and period which have low voltage problems;Firstly,the author has researched on the ways of data cleansing,and the data are collected in "four-in-one" measurement automation system.Secondly,the author uses two-way comparison to repair the omissions and mistakes;the author has researched on the clustering methods after data repairing and conducted smoothing and normalization processing on repaired data.According to the fact that residential users use more in life period whereas the customers of special transformer use more in working period,the author has drawn the daily load curve of different kinds of users referring to their features of differences in times.To master the region load characteristics,the author conducts load classification according to the clustering patterns with K-means clustering algorithm,and the basis is that the cluster shape is similar and the inter-cluster is far away from each other;Finally,the author puts forward the analysis method based on the measured load data to the low voltage problem of the low voltage distribution network with load characteristics.According to the simulation system of the distribution network feeder which is to be analyzed,load modeling is carried out in time series based on the load characteristics,and the actual line operation is made in simulation system.The aim is to analyze the influence of the change of load on the operation status of the low and medium voltage distribution network transformers in different time,to determine the leading load factor which causes the low voltage problem in the feeder,and to develop the corresponding governance programs by low voltage problem.