Structure Optimization And Power Losses Calculation Of Controllable Reactor Of Transformer Type

With the rapid growth of electricity load and the increase of demand for large capacity transmission,extra high voltage and long distance transmission have become an important development direction of transmission technology.Controllable Reactor of Transformer Type(CRT),as a new-type of controllable reactor,has the advantages of small harmonic current,fast response speed and continuously adjustable capacity,and has been widely concerned and researched recently.In this thesis,the magnetic integration technology is introduced into the structure design of CRT,and a CRT ontology structure with simple structure,easy expansion and flexible assembly is proposed.The specific content is shown as follows:(1)The working principle of CRT is analysed,and fundamental for the realization of high impedance and decoupling integrated in magnetic integration technology is introduced.(2)Based on the adjustment model of sequential single branch,concentric CRT is chosen as the research object.The general calculation formulas of the leakage magnetic field for CRT which has n windings under different loads are derived.The results show that,the magnetic flux in the iron core is gradually transferred into the air with the input of the load.Magnetic circuit calculation method and FEM have a good consistency in leakage magnetic field calculation.And the magnetic circuit calculation method is simple,rapid and easy in engineering design.(3)The design principle in structure of multiple control-windings basic-unit of magnetic integration CRT is summarized by analysing the existing structure of magnetic integration CRT.And based on it,a new-type magnetic integration structure called double control-windings basic-unit of magnetic integration CRT is proposed to solve the problem of existing magnetic integration CRT.Besides,the double control-windings basic-unit of magnetic integration CRT is compared with the existing magnetic integration CRT in many aspects to illustrate the superiority of the new-type structure.The results show that the design principle in structure of multiple control-windings basic-unit of magnetic integration CRT is very instructive in the aspect of structure design of CRT.Double control-windings basic-unit of magnetic integration CRT can match the design requirements and has obvious advantages and practical value in the aspects of volume,weight,structural complexity and so on.(4)On the condition of ignoring the leakage reactance and resistance of winding,the equivalent magnetic circuit model and the equivalent circuit model of double control-windings basic-unit of magnetic integration CRT are established.Based on it,the quantitative analysis on flux and current is made,and the calculation formulas are derived.And the magnetic field distribution in the core and the winding current at different loads are simulated by FEM of field-circuit coupling.Also,the control-winding capacity utilization radio is calculated.The results show that double contol-windings basic-unit of magnetic integration CRT can achieve smooth adjustment from no load to rated load and match the design principles of high impedance and weak coupling.Besides,it has the advantages of simple structure,high utilization radio of winding capacity and strong practicability.(5)Through the analysis of the relationship among the cost,loss and the structural parameters of double control-windings basic-unit of magnetic integration CRT,and taking the minimizing cost and loss as the optimization goal,a CRT structural parameter optimization model is established.Based on the genetic algorithm toolbox of MATLAB,the structural parameters of CRT are optimized.The results show that the CRT structure parameters optimized by the optimization algorithm are more reasonable.(6)The loss theory for double control-windings basic-unit of magnetic integration CRT is analysed.Based on the finite element analysis software ANSYS Maxwell,the loss of CRT is calculated.And the loss calculation results of FEM and the analytical method are compared.It shows that the loss calculation results of CRT based on the analytical method and FEM have good consistency to verify the correctness of the two methods.