Research On Defect Diagnosis Of High Voltage Shunt Reactor Based On Acoustic Vibration Signal

As an important part of reliable operation of power grid,high-voltage shunt reactor is the key equipment of long-distance transmission system,which can effectively compensate capacitive reactive power of UHV transmission line and improve voltage distribution.After the high-voltage shunt reactor is put into operation at full load,continuous mechanical vibration is easy to cause loosening of windings,iron cores,bolt fasteners and other structural parts.Long-term mechanical defects will further lead to increased vibration,and may also cause defects in serious cases such as overheating and discharging inside the equipment.Therefore,mechanical defects under long-term vibration are one of the important reasons for reactor faults.In this paper,the research on vibration of high-voltage shunt reactor is mainly based on simulation model,experimental platform and field application.The simulation study mainly obtains the vibration distribution and magnitude of each structure of reactor under the action of Maxwell force,magnetostriction effect and Lorentz force on the core and winding through the coupling of magnetic field and structural dynamics.Areas prone to mechanical fatigue is determined under the state of cyclic load applied to each part of fastening clamp by introducing fatigue module.Based on the equivalent scale model of reactor,the vibration characteristics of iron core and winding as well as the vibration distribution characteristics of tank surface are explored.The vibration detection sensitive area is determined by vibration main frequency and linearity between vibration intensity and voltage square based on boost voltage experiment.On the basis,by simulating the loosening fault inside the tank,the vibration characteristics of tank surface under normal state and different loosening degree of fastening rod are extracted and classified by the Empirical Mode Decomposition and Naive Bayesian network classifier.Field application is mainly aimed at the 1000kV high-voltage shunt reactor in a field substation,and the on-line monitoring system based on the vibro-acoustic signal is developed to meet the field requirements,which can meet the functions of remote control and automatic signal acquisition all the daytime.In addition,the vibro-acoustic characteristics of different 1000kV high-voltage shunt reactors are compared and analyzed to verify that the method of distinguishing the box wall vibro-acoustic characteristics for evaluating abnormal reactors’ state is practical.Finally,based on the large amount of vibro-acoustic data continuously accumulated by the on-line monitoring system,the Long-Short Term Memories model and Gated Recurrent Unit model are used to predict the vibro-acoustic characteristics of an UHV shunt reactor on site.At the same time,the deviation measurement is used to effectively evaluate the operation state of the UHV shunt reactor.The research results of this paper provided reference for vibro-acoustic characteristics and defect diagnosis methods of high-voltage shunt reactor.Combining finite element simulation,reactor scale model experiment as well as field measurement and analysis,the relevant theories of reactor vibration analysis are enriched.At the same time,it is of great significance to reactor’s operation state evaluation and defect diagnosis research based on vibro-acoustic analysis method.