±800kV UHVDC Multi-physics Simulation Study Of Filter Reactor

With the rapid development of large-scale DC transmission projects,harmonic pollution has become increasingly serious.As the main electrical equipment of HVDC power transmission projects,reactors can play the role of reactive power compensation and filtering in the power system.Therefore,reactors have been heavily invested in power transmission projects.As dry-type air-core reactors are more and more widely used in power systems,they also expose various problems during operation,which may seriously threaten the safe operation of the power grid.Dry-type air-core reactors generate magnetic fields during normal operation,and dry-type air-core reactors have serious magnetic leakage,which may affect the operation of other electromagnetic equipment and the health of workers.When the reactor is operated under the action of electromagnetic force,it will vibrate,which will cause the reactor to locally shift and deform,and the local displacement and deformation are one of the important reasons for the insulation cracking.The reactor is a coaxial multi-encapsulation structure,which makes it difficult for workers to detect the temperature rise of the internal encapsulation of the reactor.If the reactor is operated at a high temperature for a long time,it will affect its working life and cause serious insulation damage and cause fire accidents.Therefore,the multi-physics analysis of the reactor can provide a theoretical basis for the optimization and safe operation of the reactor.In this paper,the dry-type air-core filter reactor model LKK-110-342 is used as the research object to study the multi-physics field of the dry-type air-core filter reactor.First,a two-dimensional simulation model of the dry-type air-cored reactor is established,the magnetic field of the dry-type air-core filter reactor is calculated and analyzed,and the magnetic field distribution inside and outside the reactor is obtained.Through the axial and radial magnetic field analysis of the reactor,it can be found that the magnetic field at the end of the reactor diverges,and the existing magnetic leakage phenomenon will affect the normal operation of the surrounding electrical equipment and the health of the operators.Through the research on the magnetic field distribution of the reactor,it can provide a theoretical basis for the optimal design to solve the magnetic leakage problem of the reactor.Then the loss of the filter reactor is calculated according to the research results of its magnetic field,which provides a basis for the calculation of the temperature field in Chapter 4.Secondly,based on the magnetic field analysis results of the dry-type air-core filter reactor,the electromagnetic force,displacement and stress distribution of the dry-type air-core filter reactor are further analyzed,and the distribution of displacement and deformation generated by each layer of the dry-type air-core filter reactor is obtained..By analyzing the displacement and force of each layer of the dry-type hollow filter reactor and its parts,it can be found that the reactor has local deformation and large displacement due to uneven force,which can be based on the electromagnetic force of the reactor.The results of,displacement and stress distribution provide a theoretical basis for optimal design of the weak links of its mechanical strength and structural design.Finally,the fluid-temperature field coupling simulation model of the dry-type hollow filter reactor is established,and the internal temperature field distribution and the air fluid field distribution of the reactor are obtained based on the finite element calculation.By analyzing the temperature distribution of each encapsulation of the reactor and the main areas where the temperature rise is concentrated,it can be found that the encapsulation temperature rise is mainly concentrated on the top of the second and third layers of the encapsulation,and there is a local high temperature.Analyze the influence of the distribution of the air fluid field on the temperature rise,find out the reasons for the uneven temperature distribution inside the envelope,and provide a theoretical basis for improving the local temperature of the reactor.