The Research Of Single-phase Earthing Fault Line Selection Based On Interval-valued Intuitionistic Fuzzy Control

Recently,most of China's medium-voltage power distribution networks adopt the operation mode of small-current grounding systems.The current line selection methods for single-phase grounding faults in existing small-current systems have deficiencies in accuracy and reliability,and have not found effective for a long time.The method to solve this kind of problem.In order to identify the faulty line reliably,the steady-state and transient fault characteristics of the small-current system after a single-phase earth fault are systematically studied,and the fault laws of the fault line and the non-fault line are summarized.These research theories will be The selection of the text provides the theoretical basis.Aiming at the limitation of the accuracy and reliability of the single line selection method and the fuzzy line selection method,this paper proposes the fusion selection of the zero sequence current ratio method,the zero sequence active power method and the direct current method through the interval intuitionistic fuzzy selection method.The method of empirical mode decomposition can accurately extract the fault feature information after a single phase grounding fault occurs.Therefore,empirical mode decomposition is used to extract the zero sequence current component,DC component and zero sequence active power component of the line,and then construct the interval intuitionistic fuzzy number of the three characteristic information,and use the interval straight.The sense fuzzy ordered weighted average operator is used to synthesize the information,and the interval intuitionistic fuzzy decision model of the line selection system is set up.Finally,the line selection is carried out by comparing the score of the comprehensive decision.A simulation model for the single-phase grounding of the small-current system was established on the power system electromagnetic simulation software ATP-EMPT,and a large number of simulation experiments were performed using the interval intuitionistic fuzzy method.The theoretical analysis and simulation results show that this method is applied to the fault line selection The accuracy and reliability.