Theoretical Analysis On Magnetic Integration Technology Of Controllable Reactors Of Transformer Type

Control of reactive power and voltage has increasingly become the important subject ofpower system to be solved, and the core content of the subject is researching of new type ofreactive power compensation theory and technology. At present, static var compensationequipment with large capacity mainly used remains the thyristor-controlled static varcompensator, but its fatal drawback is large content of harmonic current. Essentiallycontrollable reactor of transformer type is equivalent to a multi-winding transformer whichcontrol winding work in the short-circuit state alternately, its main advantage is that we canrealize controllable grading adjustment quickly and smoothly through the control ofanti-parallel thyristors. But there is a difficulty in design of CRT is to satisfy the designprinciple of "high impedance and weak coupling", in order to realize the principle there is aneffective method that is to integrating the transformer and the limiting reactors which in seriesin the control winding loop.Magnetic integration technology is take two or more magnetic components of the powerelectronic devices through the reasonable parameters design and the conversion mode becomean integrated magnetic parts eventually, the power electronic devices such as inductor,transformer integrated on the same pair of magnetic core. Using magnetic integrationtechnology is possible to improve the power density of the device, reduce the size and theweight of magnetic component. This thesis applied magnetic integration technology in thefield of power electronics in the design of CRT innovatively.Firstly, based on the analysis of the working principle and current distribution of controlwinding of CRT, this thesis reached a design principle of "high impedance and weakcoupling". After the analysis of the calculation of power series and the current limiting reactorof CRT, then leads to a deformed and simplified structure—CRMPB(Controllable Reactor ofMultiply Parallel Branch Type).Secondly, introduces the concept of magnetic integration technology, reviews the historyof its development at home and abroad, summarize the research content and research methodsof magnetic integration technology, combined with the CRT containing four control winding,elaborated two methods to realize decoupling and integrating, then introduces the commonmethod of establishing magnetic equivalent circuit model and how to use the source transfermethod to realize equivalent conversion of the magnetic parts, and a general process ofdesigning integrated magnetic is given. Then start from the CRT deformation structureCRMPB, take the CRMPB containing one and two current limiting reactance for example,completed the design of integrated magnetic core and winding, through the analysis of therelationship between magnetic flux of each winding, and established the equivalent circuit after analyzing the magnetic circuit of integrated magnetic.Finally, the parameter of the core of integrated magnetic is designed, after the integratingthe circuit simulation model of CRMPB has been set up, and by using the simulation softwareverified correctness and feasibility of the design. The proposed integrated iron core structureprovides a theoretical basis for extending the design of magnetic integrating of CRT to theCRT containing more current limiting reactors and later work of prototype development.