【作者】 倪峰；

【导师】 余健明；

【作者基本信息】 西安理工大学 ， 电力系统及其自动化， 2008， 硕士

【摘要】 线损率是表征电力工业经济效益和技术管理水平的综合性指标。准确的线损理论计算为电力部门分析线损构成、制定降损措施提供了依据。本文首先针对低压配电网结构比较复杂,分支线路多,负荷性质复杂,历史资料不全等特点,对负荷进行合理分类,建立典型负荷曲线,采用了基于模糊聚类分析理论的计算代表日选取方法。随后在对一些配电网理论线损计算方法进行深入研究的基础上,提出了一种适合目前0.4kV低压配电网理论线损计算的“改进等值电阻法”,其基本思想是,考虑了三相不平衡度对低压线损的影响,计算线路损耗时采用实时计算的三相不平衡系数,在“等值电阻法”的基础上改进了低压线路损耗的计算方法。并针对大部分低压配电台区未安装负荷测试仪,无法采集到代表日整点电流数据的特点,提出了一种基于台区负荷分类确定动态三相不平衡度的方法。最后,基于VC6和SQL server 2000,开发了一套图形化的低压配电网理论线损计算软件。该图形化应用软件具有功能强大、人机界面友好、操作简便,图形效果美观等特点。更多还原

【Abstract】 The distribution lines loss rate is the comprehensive sign of the industrial economic effectiveness of the power system and technique, manage level. Exact computing of rate of theoretical net loss provides the engineers in power system with data to make out content of lines loss and adopt exact measure to reduce net loss.The low-distribution networks structure were more complicate, and had many branches, many kinds of loads, historical data were not whole. Based on the characteristic above mentioned, the paper classifies the types of loads and makes up the representative curve of load and pointed out a choosing representative day method based on fuzzy clustering theory. Subsequently, the paper pointed out a method—improved equal electric resistance method. The basic thought of 0.4kV lower distribution lines is using to replace the power energy of 10kV distribution lines with power energy of the distribution transformer and to replace capacity of distribution transformer with power device capacity of user to calculate distribution lines equal resistance.In addition, considering the unbalance in three phrases of main line, the paper adopts the real-time value of unbalance in three phrases to compute lines loss and pointed out the concept-real-time unbalance in three phrases coefficient. Computing of lines loss in low-voltage network is more improved based on method of improved equal electric resistance method. Due to mostly low-voltage network is lack of current date in the representative day. So the paper brings forward a method that is calculating dynamic value of unbalance in three phrases based on load classification.Finally, with VC6.0 and SQL server 2000, a graphical low-voltage network theoretical line loss calculation software is developed. This software has characteristics of strong function, good human-computer interaction interface, convenient operation, beautiful graphical effect.更多还原