Vibration Mechanism And Vibration Reduction Measures Of Ultra-High Voltage Shunt Reactor Core

UHV shunt reactor is one of the important equipment in UHV AC transmission project,which can compensate the capacitance effect of long-distance line and restrain the rise of power frequency voltage.Excessive vibration and a series of problems caused by it are one of the main problems in the operation of UHV shunt reactor.The core vibration is the main source of the vibration of UHV shunt reactor,so it is of great significance to study the vibration reduction measures of UHV shunt reactor core to ensure the safe and stable operation of the equipment.In this dissertation,the vibration reduction design of UHV shunt reactor core is the main purpose.Focusing on the mechanism and characteristics of core vibration generation and propagation of UHV shunt reactor,a comprehensive and systematic analysis is carried out by means of finite element simulation and experiment,and a vibration reduction method of UHV shunt reactor core based on gap structure is proposed.The main contents of this dissertation are as follows:The structural characteristics and vibration mechanism of UHV shunt reactor core have been deeply studied in this dissertation.There are some problems with the existing vibration calculation methods,which are the lamination rules of the oil-immersed UHV shunt reactor core cannot be accurately characterized and the influence of the fluid-solid coupling has not been analyzed.The core structure characteristics of UHV shunt reactor are analyzed.Moreover,the three-dimensional anisotropy of the magnetic properties of the silicon steel lamination is studied.A set of laminated coordinate systems is defined based on the laminated structure of the UHV shunt reactor core.The mapping of the laminated coordinate system to the spatial Cartesian coordinate system is constructed,and the conversion of parameters in the two coordinate systems is realized.The influence of the fluid-solid coupling between the core and the transformer oil on the vibration is considered.The electromagnetic-mechanical multi-field coupling model is referenced.The calculation method of UHV shunt reactor core vibration considering core lamination rules and fluid-solid coupling is proposed.The calculation method for the core vibration of the oil-immersed double-column UHV shunt reactor,which contains radiant structure core cakes,was proposed innovatively.Finally,the accuracy of calculation results is verified by UHV shunt reactor Equivalent model.It lays a theoretical and methodological foundation for the study of vibration characteristics and vibration reduction technology of UHV shunt reactor core.The vibration characteristics of UHV shunt reactor core under typical structure and operation state have been studied.In view of the lack of systematic research on the vibration characteristics of UHV shunt reactor core at present,the vibration characteristics of UHV shunt reactor core under typical structure and operation state are studied.Based on the core vibration calculation method proposed in this dissertation,the vibration characteristics and differences of single column and double column UHV shunt reactor cores under rated operation conditions are studied,and it is concluded that the core vibration intensity of single column type UHV shunt reactor is less than that of double column type shunt reactor under the same operation conditions.The equivalent model of UHV shunt reactor is used to carry out experiments,and the accuracy of the core vibration calculation method proposed in this dissertation in analyzing core vibration parameters under various operation conditions is verified.The typical voltage fluctuation forms of UHV AC power grid under normal and abnormal operation conditions are studied,and the vibration characteristics of UHV shunt reactor core under fluctuating voltage are analyzed and calculated,and it is concluded that the core vibration parameters of UHV shunt reactor are linearly related to the operating voltage of the reactor under the three operating conditions studied in this dissertation.Through the test data of UHV shunt reactor equivalent model,the characteristics of UHV shunt reactor core vibration signal are analyzed.By systematically analyzing the vibration characteristics of UHV shunt reactor core,the goal and direction of core vibration reduction design are defined.The vibration propagation of UHV shunt reactor core is studied.In order to clarify the relationship between the existing standards on the vibration of UHV shunt reactor body(oil tank)and the core vibration,and with the difficulty in analyzing the core vibration propagation caused by the complex internal environment of the reactor,the correlation between the core vibration and the oil tank vibration of UHV shunt reactor is studied.Based on the equivalent model of UHV shunt reactor,several vibration sensors are arranged on the core of the equivalent model of UHV shunt reactor and the outer wall of the oil tank.By applying eight different operating voltages,the vibration signals of the internal and external measuring points of the reactor under corresponding operating conditions are obtained.The effect of Pearson correlation coefficient,reciprocal Euclidean distance and frequency-domain confidence factor in vibration correlation analysis is analyzed.The reciprocal Euclidean distance under different voltage levels is selected as the basis for correlation evaluation.Finally,the correlation between the vibration signals of the outer wall and the inner core of the reactor is analyzed.It is found that the vibration state of the reactor tank can reflect the vibration state of the core to a certain extent,and the more direct the propagation path is,the stronger the correlation is.And it provides theoretical support for the research of UHV shunt reactor vibration reduction by means of core vibration reduction design.The vibration reduction method of UHV shunt reactor core is studied.In order to solve the problem that the vibration of UHV shunt reactor is easy to exceed the standard,a vibration reduction method,which is different from the conventional technical means of changing external conditions and core materials,of UHV shunt reactor core based on gap structure is proposed.The theoretical basis and influence law of the influence of gap structure on the vibration parameters of the core are expounded and analyzed.The optimization model of the core structure of UHV shunt reactor is proposed.Based on the core calculation model of double column UHV shunt reactor,two groups of simplified models of core structure of 31 5-gap UHV shunt reactors are designed.The influence of gap position and length on core vibration parameters is systematically studied,and the gap structure optimization scheme of 5-gap reactor is proposed.Two small dry-type double column reactors were designed and manufactured to verify the vibration reduction effect of the optimized scheme.Combined with the gap structure optimization scheme and the core design requirements of UHV shunt reactor,the core structure optimization design proposal of UHV shunt reactor is put forward,and the influence of gap structure adjustment on the main design parameters of reactor is also analyzed.The research method and conclusion of this dissertation can provide guidance and reference for the design of UHV shunt reactor on the premise of safety and economy.