| Dry-type air-core reactors are the main facilities in the power system and play an important role in current limiting,filtering,flat wave,reactive power compensation,etc.At the same time,when the alternating voltage excitation is applied in actual work,it will cause reactor coils.Vibration will not only cause reactor noise,affect the normal life of nearby residents,but also may cause the coil to become loose and affect the normal operation of the equipment.In severe cases,it will damage the reactor and cause accidents.Therefore,the study of the vibration characteristics of dry-type air-core reactors is a prerequisite for their normal operation.By obtaining the external excitation of the system and the inherent structural characteristics of the system,the vibration of the system under this excitation can be obtained.In order to better understand the vibration state of the air-core reactor during normal operation,this paper mainly studies the excitation electromagnetic force and the mode shape and frequency of the air-core reactor when the dry-core reactor is subjected to alternating voltage.First,the coil structure of the air-core reactor is simplified,and a three-dimensional model of a multi-layer coaxial hollow cylinder type coil is created,and the magnetic induction intensity and electromagnetic force distribution are obtained by analysis using electromagnetic software;then the structural parameters of the reactor coil are discussed.The change of the electromagnetic force of the air-core reactor under the same power frequency voltage excitation when changing.Then,a three-dimensional model including hollow cylindrical coils,stays,star frames,and bottom pillars was built on a dry-type air-core reactor.The free-mode analysis of air-core reactors was performed,and the comparison of free-star reactors to free-mode reactors was performed.The effect of the state is analyzed on the influence of coil structure parameters on the free modal of the air-core reactor.Finally,the modalities of the dry-type air-core reactor were measured from the test angle,and the experimental modal shapes and frequencies of the reactor were obtained. |
