Abstract: Effective evaluation of voltage characteristics of low-voltage distribution networks provides the decisionmaking basis and reference for power supply enterprises to screen and manage low-voltage distribution networks． As it is difficult to evaluate and screen the voltage characteristics of large numbers of low-voltage distribution networks，an evaluation method of the voltage characteristics of low-voltage distribution networks is proposed based on the efficacy coefficient method． First，a set of evaluation index system of low-voltage distribution networks is established，which considers the voltage characteristics of all lines，and the evaluation indexes are standardized to become the unified and very large efficacy coefficients． Then，each evaluation index is weighted by means of the order relation-open class weighting method，which embodies the difference among evaluation objects and the experts’will and thus helps
to evaluate and screen voltage characteristics scientifically． Finally，the comprehensive efficacy coefficients of the voltage characteristics of low-voltage distribution networks are calculated，so that the entire evaluation and screening process is completed． A case study shows that the proposed methodis applicable and effective and that it is suitable for guiding the evaluation and screening of the voltage characteristics of low-voltage distribution networks．

Key words: low-voltage network, voltage characteristics, comprehensive evaluation, efficacy coefficient method, order relation-open class method