Research On Arc Extinguishing Characteristics Of High-speed Circuit Breaker Arc Extinguishing Chamber And Impact Dynamics Of Transmission Mechanism

In order to speed up the construction of a multi-integrated,efficient and flexible smart grid and meet the wide-scale development of short-circuit current flexible suppression technology,SF6 circuit breakers have an irreplaceable role in limiting short-circuit current in the power system.Compared with other types of switches,The SF₆circuit breaker quickly and reliably removes faulty components from the power grid,ensuring safe and reliable operation of the power system.On the basis of the conventional opening speed circuit breaker,improving its response speed and compressing the short arcing time of the arc extinguishing chamber can improve the response ability of the circuit breaker to faults,and this also puts forward higher requirements for the performance of the circuit breaker itself.After the opening speed is increased,the arc quenching performance of the arc quenching chamber and the mechanical reliability of the power supply system are very different from the breaking characteristics of the conventional opening speed circuit breaker.To better assess the breaking capacity of fast circuit breakers,this paper studies the arc-extinguishing characteristics of the high-speed arc extinguishing chamber and the impact dynamics characteristics of the transmission mechanism based on the new high-speed breaking technology for suppressing short-circuit current in the power grid.The main aspects are as follows.Work:（1）The high-speed breaking process simulation model is established,considering the influence of turbulence and radiation heat transfer process in the interrupting process of the arc chute,and based on the basic control equation of the gas flow field and the gas state equation,the multi-physics coupling mathematics under the interrupting of the arc chute is established.The model is simplified according to the actual arc interrupter structure and a two-dimensional axisymmetric calculation model is established,and the moving mesh is divided to simulate the movement process of the moving contact opening;the transmission mechanism is established based on the impact dynamics theory.The high-speed breaking dynamics equation,the three-dimensional calculation model is established based on the structure of the transmission mechanism,and the material parameters of the simulation model are set based on the actual component materials,and the calculation model is loaded with the measured kinematics parameters.A research model for the breaking process.（2）Research on arc-extinguishing characteristics of high-speed arc-extinguishing chamber.Based on the numerical calculation model of high-speed breaking arc characteristics of the arc extinguishing chamber,the no-load breaking process is calculated and analyzed,the gas blowing process under high-speed conditions is studied,and the short arc and long arc breaking processes are simulated.The dynamic process of the arc and the gas compression characteristics at different monitoring points in different stages during the breaking process are analyzed,and whether the short-circuit current can be cut off reliably after the short arcing time is compressed is studied.（3）Calculation of impact dynamics of high-speed transmission mechanism.Considering the influence of the circuit breaker pressure cylinder on the breaking process of the transmission mechanism,the reaction force is applied to the breaking process based on the simulation results of the airflow field.The kinematic parameters of the transmission mechanism were compared and analyzed to verify the accuracy of the dynamic simulation model.Through the calculation,the change process and distribution of the stress of the whole transmission mechanism with the opening time during the high-speed breaking process are obtained,and the key components are calculated and analyzed separately,and the stress distribution at different times is obtained.Finally,the vibration characteristics of the moving contact are calculated and the influence of different materials on the vibration of the moving contact is compared and analyzed.