Establishment Of Hysteresis Model Of Power Transformer Based On Two-phase Magnetic Material And Manufacture Of The Prototype

The electrode current of HVDC transmission system enter into the winding of thetransformer through the neutral point, which leads to the core of transformer increases, rise ofthe temperature, enhancement of pulsation, damage of the transformer etc. Then the safety ofthe whole power system can be affect by above aftermath. With the worldwide application oflarge capacity and long distance HVDC, At present, phenomenon of DC magnetic biasreceives takes more and more. However, it is not solved well to suppress the DC magnetic biaseffectively. A new type of power transformer with DC magnetic bias suppression function willbe researched from the perspective of two magnetic material, according to the controllablecharacteristics of the material.Firstly, mechanism of hysteresis model and the basic characteristics and preparationmethod of two-phase magnetic material were discussed.Then magnetic properties wereresearched through the Jiles-Atherton model. Microstructure, preparation process, two phasetransition process of the two magnetic material were researched to prepare suitable twomagnetic material. The control circuit was designed which can achieve the shift between thehard and soft characteristic, and then it can achieve the control of the core magnetic properties.Secondly, the new structure of transformer with DC magnetic bias suppression functionbased on magnetic two-phase materials was put forward. The simulation of the new powertransformer was studied by the co-simulation model built by MATLAB, Simplorer and Ansoft.Excitation current waveform and loss characteristics of transformer under no dc bias, dc biasand situation after inhibition are obtained. The correctness of the design was verifiedaccording to contrast analysis.Finally, two220V/110V/1kVAmodel of new power transformer prototype were preparedand the DC magnetic bias circuit experiment was carried out according to design of the powertransformer. Contrast of the experimental data under no dc bias, dc bias and compensation,verify the good effect of the new power transformer with DC bias suppression function.