| In electric power system,dry type air-core reactors are the main auxiliary equipment for long-distance transmission systems.The function is to limit the shortcircuit current,reactive power compensation,and equalization of power transmission system.Dry type air-core reactors play an important role in power transmission system because of the excellent electrical performence.During the daily operation of the reactor,due to the eddy current thermal effect and heat generation of the package,the star-shaped rack is exposed to extreme currents with high currents,high voltages and strong magnetic fields at any time.Thus Overheating lead to the normal operation of the reactor in the top and bottom ends of the star-shaped rack around the burning loss or even fire.This has brought huge losses to country,businesses and even the people,and has caused tremendous damage to the surrounding environment.Therefore,the use of finite element analysis method to study the influence of the thermal effect of the spider on the encapsulation temperature and compare the temperature distribution data of the previous fiber Bragg grating detection reactor envelope.Those make great significance to the development of the power system and significant practical value.Aiming at the structural characteristics and detection requirements of dry type aircore reactors,finite element analysis method and data comparison method are used to effectively study the influence of the thermal effects of the star-shaped rack on the encapsulation temperature of dry type air-core reactors and compare the simulation with temperature rise test data.The research content of this article mainly includes:(1)According to the structure of the dry type air-core reactor,the characteristics of its star-shaped rack,and under the condition of the dry type air-core reactor working,the wire on the star-shaped rack is energized to generate current,and a vortex is generated at the center ring of the reactor.The effect is that the eddy current heat dissipates heat to the brackets in all directions of the star-shaped rack,the eddy current thermal effect of the star-shaped rack is analyzed and studied,and the finite element method of the dry type air-core reactor is combined with the actual parameters of the reactor and heat transfer knowledge.Eventually a finite element model in 1:1 actual size of the reactor is established.(2)Use ANSYS WORKBENCH to perform the finite element analysis on the dry type air-core reactor to obtain the temperature distribution diagram of the dry type aircore reactor with eleven-layer encapsulation without star-shaped rack.For the eddy current thermal effect of the spider,the influence of the thermal effect of the reactor star-shaped rack on the encapsulation temperature is obtained through finite element analysis,and whether the first,third,fifth,sixth,seventh,ninth,and eleventh layers are encapsulated The temperature distribution of the encapsulation under the influence of the star-shaped rack is compared,and the influence of the thermal effect of the starshaped rack on the encapsulation temperature is analyzed.The influence of the thermal effect of the star-shaped rack on the encapsulation temperature is decreased from the both sides to middle of the encapsulation layer.The first layer is affected more than the sixth layer does.(3)Through the previous reactor temperature rise test,the optical fiber Bragg grating temperature sensor and the installation position distribution of the sensor ar e introduced respectively.The on-line detection of the temperature rise process is performed through the constructed fiber Bragg grating temperature sensor network.The actual measured data of the encapsulation temperature is compared with the simulation result data and analyzed.The analysis result is that the test data is basically located in the range of simulation data.Through data analysis,it provides the basis for the safe operation of dry type air-core reactors.In this paper,the influence of the thermal effect of the star-shaped rack of a dry type air-core reactor on the temperature distribution of the reactor envelope is analyzed through finite element analysis and data comparison.During the implementation process,the reactor structure modeling,finite element simulation and data comparison are accomplished.The above experience has important reference value for fire prevention and on-line detection of dry type air-core reactors in power transmission systems. |
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