Coordinated And Cooperated Between H-SFCL And Relay Protection Of Power System

With the increasing scale of power systems,the level of short-circuit currents is increasing.The short-circuit current of concentrated area power grids in China is close or even exceeds to the rated breaking capacity of existing circuit breakers,which seriously jeopardizes the safety operation and reliability of system.Due to the superior characteristics of superconducting current limiter which is considered to be the most promising new current limiters.However,when the superconducting current limiter was connected to the power grid which its characteristics may have a certain impact on the operation of the power system and relay protection actions.For this reason,it is necessary to systematically study the coordination and cooperation between superconducting current limiter and relay protection of power system.This thesis select the hybrid superconducting current limiter(H-SFCL)as the research object through systematic analysis and comparison of various types of superconducting current limiter.Analyzed the structural characteristics,working characteristics and parameter characteristics of H-SFCL.Established the mathematical model and the simulation mode of H-SFCL which was studied the correctnessl in the example system.Study the impact of H-SFCL on action current or action impedance,action time limit and action sensitivity which about the current protection,distance protection,zerosequence current protection,longitudinal protection and automatic reclosing protection,and then propose corresponding coordination strategies respectively.By reseting the action current or action impedance,action time limit and sensitivity in the relay protection to which eliminate the influence of H-SFCL on it and ensure the protection selectivity,quickness,sensitivity and reliability of relay protection.The the simulation model of example system was built on the MATLAB/Simulink simulation platform,and studied the effectiveness and correctness of the coordination and cooperation strategy between H-SFCL and relay protection proposed in this paper through simulation experiments.Aiming at the problem of multiple H-SFCL configuration in power system,established an objective function and constraint conditions for optimal configuration of H-SFCL in power systems with the goal of satisfying current-limitation requirements and configuration economy.According to the characteristics of the established multi-objective function,an improved particle swarm algorithm is used to solve the problem in order to obtain the number of configuration position and configuration capacity.The optimization and research of configuration were carried out in IEEE 39-bus test system and the results verified the validity and reliability of the model and algorithm.