Research On Characteristics Of Controllable Reactor Of Transformer Type Based On ANSYS

The unbalanced distribution of energy resources and power load in China promotes the rapid development of ultra-high voltage cross-regional long-distance transmission technology and power electronics technology.At the same time,the problems of reactive power balance and voltage fluctuation,flicker and distortion are becoming more and more prominent.As a kind of reactive power compensation equipment,Controllable Reactor of Transformer type(CRT)has the advantages of simple structure,fast response speed and continuous and smooth adjustment output of inductive reactive power.Therefore,the transformer type controllable reactor is suitable for the uhv ac transmission system to ensure the balance of reactive power in the long-distance and large-capacity transmission lines,suppress the line overvoltage and maintain the voltage stability of the power grid.In this paper,controllable reactor of transformer type is taken as the research object.Firstly,The structure and basic working principle of single-phase and three-phase CRT are introduced respectively,and the working characteristics are analyzed theoretically.Secondly,a field-circuit coupled multi-physics joint simulation method is used to analyze the working characteristics of the transformer-type controllable reactor.The finite element electromagnetic software ANSYS Mawell is used to establish the two-dimensional model of three-phase three-column CRT,Maxwell is combined with Simplorer to build a complete simulation experimental circuit in the simulation platform.Then,the simulation experiment is carried out by adjusting the trigger angle of thyristor to obtain the current of working winding under different working conditions,the relationship between the trigger Angle of the thyristor and the fundamental current on the network side is studied,and the control characteristic curve of CRT is obtained.Finally,the harmonic analysis of the working current is carried out,the curve of the total harmonic and every harmonic current with the trigger angle of thyristor is obtained,and the two ways of changing the winding pitch and increasing the third winding are studied respectively.It was found that thecontent of total harmonic and every harmonic is obviously reduced,which effectively decreases the harmonic pollution.The simulation results show that three-phase three-column CRT meets the requirement of continuous and smooth output of inductive reactive power,and the joint simulation method makes up for the shortcomings of ignoring their own structure and material settings in the simulation software Matlab/simulink or PSCAD,and the variation of the internal magnetic field of the reactor core can be analyzed in this software.The working state of CRT is simulated accurately,which can provide more accurate analysis results.