Simulation Research On Magnetic Field And Temperature Field Of New Compound Contact Vacuum Interrupter

12k V vacuum interrupter is widely used in medium voltage fields because of its small volume and strong breaking capacity.At present,it is developing towards miniaturization,high voltage,and high current.How to effectively control the high voltage arc and optimize its breaking capacity by changing its contact structure is one of the research hotspots in this field.The miniaturization is easy to cause the internal temperature,especially the contact part,to be too high and reduces the service life.Therefore,it is particularly important to accurately simulate the internal temperature rise.Therefore,a new composite contact structure is proposed in this paper,and its magnetic field and temperature field are simulated and analyzed by the finite element method.The prototype model of a 12 k V vacuum interrupter is established by Solid Works,and then the magnetic field simulation and temperature field simulation of the prototype model is carried out by using the finite element analysis software ANSYS Workbench in this paper.Combined with the analysis results,the vacuum interrupter model is optimized.First to establish the cup shape and longitudinal magnetic,swastika compound word,chute composite magnetic field,and spiral composite four contact model simulation,compared with other three-cup shapes and longitudinal magnetic composite contactor structure in the center of the arc current peak time of the plane of magnetic induction intensity,the largest effective scope and current zero point magnetic lag time,the results showed that: Swastika composite contact has good magnetic field characteristics.Then response surface test and multi-objective optimization design are carried out for the structure of swastian-shaped contact.The specific parameters of the structure under the optimal magnetic field characteristics are obtained: the rotation angle of the finger is 110°,the horizontal angle of the finger is 20°,the slot length is25 mm,the slot angle is 0°,and the diameter of the transverse magnetic contact is 30 mm.For the swastika-shaped compound contact structure,the temperature rise of the vacuum arc extinguishing chamber under unidirectional and bidirectional magneto-thermal coupling conditions was compared,and the effects of load current,ambient temperature,and convection coefficient on the temperature field of the arc extinguishing chamber were studied.The results show that :(1)the material temperature has an important influence on the temperature rise of vacuum arc extinguishing,and the magneto-thermal bidirectional coupling is adopted to simulate the actual temperature rise.(2)When the carrying current increases,the temperature rise of the interrupter chamber also rises,and the relationship between them is approximately linear;when the ambient temperature of the vacuum interrupter chamber increases,its temperature rise will also rise,and the relationship between them is linear.When the convective coefficient increases,the rise of vacuum arcing room temperature decreases.Finally,the temperature field of the vacuum arc extinguishing chamber under the condition of contact fault is simulated,and the temperature rises time-varying curve of each component and the temperature rise distribution under the condition of contact fault are obtained.The results show that :(1)when only the contact fault occurs,the maximum temperature is 134.92℃,which is located at the contact of two contacts.Except for the conductive copper bar,the temperature rise of other parts is more than 65 K.(2)When the lower conductive copper bar contact failure,the highest temperature is 102.04℃,located at the soft connection and the lower conductive copper bar contact,only the temperature rise of the upper conductive copper bar is less than65 K,the temperature rise of other parts is greater than 65K;(3)When the upper conductive copper bar contacts the fault,the highest temperature is 104.43℃,located at the contact point between the static conductive rod and the upper conductive copper bar at the fault point,the temperature rise of the lower conductive copper bar and the soft connection is less than 65 K,and the temperature rise of other parts is serious;(4)When the two copper bars are in contact fault,the highest temperature appears at the contact point,the value is 122.61℃ and the temperature rise of the whole conductive circuit exceeds 65K;(5)When the contact and copper bar contact fault,the highest temperature position occurs at the contact,the value is 196.39℃,conductive circuit heating is the most serious.