Random vibration characteristics of air core reactor based on multi physics field coupling theory
                                       YING Cheng wei1, LI Shui qing2, WANG Wen hua3, JIN Li jun1
（1.College of Electronics and Information Engineering, Tongji University, Shanghai 201804, China；2.Chint Electric Co., Ltd., Shanghai 201614, China；3.Jiaxing Power Supply Company, State Grid Zhejiang Power Supply Company, Jiaxing 314000, China）

Abstract: The vehicle air core reactor can be influenced by the random load from the train along with the electromagnetic force and thermal stress of the reactor itself during its operation.Aiming at the vibration stability problem of air core reactor under the influence of multiple loads, firstly the 3D finite element model of air core reactor influenced by random load from the train was established to analyze the distribution characteristics of the natural frequency of winding of the reactor. Secondly considering the mutual influence of electromagnetic force and thermal stress of current carrying air core reactor, the multi physics model of air core reactor was built, and solved through the multi field coupling calculation by fusing random load, electromagnetic force and thermal stress together.The research results show that the combined effect of multiple loads increases resonance frequency of the air core reactor with the resonance amplitude becoming larger. The structure strength is thus reduced, the electrical performance will drop.

Key words: air core reactor; random load; electromagnetic force;thermal stress;multi physics field coupling