摘要
随着直流配电网的发展和分布式储能、光伏大规模接入配电网,配电网结构发生革命性变化,直流配网发生短路故障后短路电压急剧下降,短路电流迅速上升,电力系统运行稳定性遭到破坏。针对此问题,提出直流系统极间和单极短路故障模型,首先通过直流线路两端电压采样数据,列写电压方程并消除过渡电阻;然后构造适应度函数,采用收敛速度更快、定位精度更高的改进红狐优化算法计算故障点到保护安装处的距离,用于直流配电网故障定位。在红狐算法基础上结合孤立森林算法剔除异常数据,通过改进可调节反馈因子、引入遗传交叉算子提高算法性能和精度,在采样频率偏低时通过自适应插值提高故障定位准确率。在Simulink中进行仿真验证,结果表明该方法抗过渡电阻能力强,定位误差小,不受系统参数影响,能够有效降低采样频率偏低对故障定位的影响,且具有良好的鲁棒性。
With the development of DC(direct current)distribution networks and the large-scale integration of distributed energy storage and photovoltaics into the distribution network,the structure of the distribution network has undergone revolutionary changes.After a short circuit fault occurs in the DC distribution network,the short circuit voltage drops sharply,the short circuit current rises rapidly,and the stability of the power system operation is disrupted.To address this issue,a model for inter pole and single pole short circuit faults in DC systems was proposed.Firstly,by sampling voltage data at both ends of the DC line,the voltage equation was written,and the transition resistance was eliminated.Then,a fitness function was constructed,and the adaptive optimization red fox algorithm with faster convergence speed and higher positioning accuracy was used to calculate the distance from the fault point to the protection installation site for fault location in the DC distribution network.Based on the red fox algorithm,combined with the isolation forest algorithm to remove abnormal data,the algorithm performance and accuracy were improved by improving adjustable feedback factors and introducing genetic crossover operators.When the sampling frequency is low,the accuracy of fault localization is improved through adaptive interpolation.Simulation verification was conducted in Simulink,and the results show that the method has strong resistance to transition resistance,small positioning error,is not affected by system parameters,and can effectively reduce the impact of low sampling frequency on fault localization,and has good robustness.
作者
徐岩
唐琪尊
姚梓琦
孙佳毅
XU Yan;TANG Qi-zun;YAO Zi-qi;SUN Jia-yi(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Baoding 071003,China)
出处
《科学技术与工程》
北大核心
2025年第17期7197-7207,共11页
Science Technology and Engineering
基金
河北省重点研发计划(20314301D)
国家电网有限公司科技项目(kj2021-003)。
关键词
直流配电网
故障定位
参数识别
直流系统
精准定位
孤立森林算法
改进红狐算法
DC distribution network
fault location
parameter identification
DC system
accurate positioning
isolation forest
improved red fox optimization
