Multi-objective optimization of relay protection settings for distribution networks with high permeability of distributed photovoltaics
SHI Hengchu
ZHOU Haicheng
LI Yinyin
XU Yu
ZHENG Quanchao
Abstract：[Objective]The influence of photovoltaics(PV)-assisted current and extraction current on conventional relay protection hinders the effective functioning of relay protection equipment.A multi-objective setting method for relay protection in distribution networks suitable for conditions with high permeability of distributed PV was proposed to address this problem,which is aimed at enhancing the rapidity,sensitivity,and selectivity of protection,and ensuring economic viability and practicality,thus effectively safeguarding the power grid security and supporting the widespread access of distributed PV.[Methods]The influence of PV-assisted current and extraction current on the protection configuration of the distribution networks was analyzed,and the problem of unwanted operation and refuse operation of distribution network protection caused by PV access was avoided by introducing distance protection and instantaneous current protection as the protection criteria.A multi-objective optimization model with the optimal parameters of protection rapidity,sensitivity and selectivity was built,and the particle swarm optimization(PSO)algorithm was improved by adopting the dynamic splitting operator to make the solution of the protection setting meet the practical application requirements.[Results]High-permeability distributed PV results in unwanted operation or refuse operation of distribution network protection,which is effectively avoided by introducing distance protection and instantaneous current protection as the protection criteria.The multi-objective optimization protection configuration model was built,and the evaluation indexes of the overall protection effect of a certain area were formed,with the solution of the protection setting completed based on PSO algorithm.Finally,the overall evaluation of the protection effect under high-permeability PV access was realized,with the rapidity,sensitivity,and selectivity of protection improved.[Conclusions]The results show that the combination of distance protection and instantaneous current protection can effectively avoid the influence of the PV-assisted effect on the conventional instantaneous current protection.The protection performance can be effectively improved by the proposed multi-objective optimization scheme.Under the equilibrium strategy,the rapidity,sensitivity,and selectivity increase by about 82.2％,about 3.8％,and about 33.1％,respectively.The innovation of this study is that the combination of distance protection and instantaneous current protection was adopted to form the protection criteria,thus avoiding the problem of unwanted operation and refuse operation of the distribution network protection due to PV access.Additionally,a multi-objective optimization scheme for protection settings was constructed,and PSO algorithm was improved by employing the dynamic splitting operator,thereby avoiding the limitations of PSO algorithm and improving the reliability and applicability of protection settings.
Keywords：distributed photovoltaicsdistribution networkrelay protectionrapiditysensitivityselectivityparticle swarm optimization algorithmsplit operator
Publication Date：2025-11-25
Online Publishing Date：2025-12-29(First online date of this platform, not the publication date of the document)
Pages：7( 688-694 )