实用系数常用于指导业扩报装时配变容量的选取． 文中针对当前实用系数选取时灵活性差、受样本数据影响较大、没有考虑负荷发展特性等问题，设计了一种基于模糊聚类的实用系数分析方法． 首先，将用电用户划分为商业、住宅、工业等类型，并建立相应的用电用户的评价指标体系，该体系选取负荷密度、年用电量增长率、配变投运时间3 个评价指标来分别描述用电用户的用电水平、变化情况以及负荷发展特性; 然后，设计了基于模糊聚类的实用系数等级划分方法，该方法根据3 个评价指标进行模糊聚类，划分出实用系数等级，并确定各等级的评价指标及实用系数的中心值; 最后，根据待测用电用户的评价指标值与各等级中心值的加权距离和，求得实用系数等级及相应的实用系数值． 通过实例分析，验证了该方法的有效性和实用性．

Practical coefficient is usually applied to the selection of distribution transformer capacity for the business expending.As the existing practical coefficient selection methods with low flexibility are greatly affected by dataand do not take into consideration the load development feature,a method to analyze the practical coefficient based on fuzzy clustering is proposed.In this method,first,power usersare divided into such three types as business,house and industry,and the corresponding evaluation indexes,namely the load density,the annual growth rate of electricity consumption and the commission time of distribution transformer,are used to describe the power consumption level and its variation as well as the load development feature of power users.Then,a classification method of practical coefficient levels is designed based on the fuzzy clustering,which uses the three above-mentioned evaluation indexes to perform a fuzzy clustering for the coefficient level classification and determines the evaluation index and practical coefficient's central value of each classification.Finally,the level and value of the practical coefficient of a new power user are obtained according to the sum of the weighted distance between the index value and the central value of each classification.In addition,the effectiveness and practicability of the proposed method are verified through a case study.