Design Of Electromagnetic Mechanism For Control And Protective Switching Device With Dynamic Opening Distance

Given that the maximum opening distance of the existing control and protective switching device shall be increased when higher level short-circuit current,and then the power consumption of switch closing is increased,this thesis carries out the research towards the short circuit cut-off process of switch.Under the premise of guaranteeing the reliable switch work,a kind of design plan with the electromagnetic mechanism for the control and protection switchgear with dynamic opening distance institutions is proposed for the main purpose of improving the breaking capacity of short circuit and reducing the switching power.As per the cut-off feature requirement of the control and protective switching device,the electromagnetic organization structure and contact parameters are confirmed on the basis of electromagnetic theory and low-voltage electric switch designing experience,and the inverse force characteristic of electromagnetic system of switch electromagnetic mechanism,iron core and coil are researched and calculated.In this thesis,the Matlab software simulation is applied to analyze the short-circuit current impact factors,the short-circuit art model is established,and the optimal armature displacement curve is designed in combination with the arc energy principle;the AMESim software is applied to establish the mechanism motion model to analyze the influence factor of armature displacement and its influence of cut-off characteristics;the software is used to conduct the parameter optimization of armature displacement in order to achieve the optimal armature displacement curve in combination with the mechanics and kinematical equation.Finally,the dynamic opening distance is designed successfully.On the basis of the theoretical design and simulation analysis,the electromagnetic mechanism sample for control and protection switchgear with dynamic opening distance is produced.The test circuit is designed,and the experimental circuit is established to conduct the opening and closing experiment of switch under the rated working conditions;the short-circuit breaking capacity test is conducted at the test station.The test result of opening and closing experiment and short-circuit breaking capacity test indicates the electromagnetic mechanism could conduct reliable operation and conduct the cut-off of large short-circuit current,which verifies the feasibility of the design scheme of the electromagnetic mechanism for control and protection switching device with dynamic opening distance,and effectively reduces the energy consumption upon the switch closing,which has certain theoretical significance and practical value.