| Accurate measurement and Simulation of two-dimensional magnetic properties of electrical soft magnetic materials are of great significance to the optimal design and energy saving of motors and transformers.It is one of the effective ways to improve the operation efficiency of the power grid.The key to two-dimensional magnetic characteristic measurement lies in the structure of the excitation device and the measurement system's design.Given the above problems,this paper has done the following work:1.A new type of two-phase winding excitation device based on circular sample is proposed.The magnetic characteristics of silicon steel yokes of the excitation device are measured at different angles by using the mature Epstein square circle method.The hysteresis loops and magnetization curves under different magnetization angles are obtained,which provides data basis for the finite element analysis of electromagnetic characteristics of the excitation device.Based on the measured data,the finite element analysis model is established considering the magnetic core structure and the anisotropy of magnetic properties of silicon steel sheet,and the two-dimensional discrete analysis is carried out.The new two-phase winding magnetic measurement device is compared with the 16 pole Halbach type excitation device,induction motor type excitation device and three-phase winding type excitation device based on circular sample by two-dimensional finite element simulation.The excitation performance and magnetization uniformity are analyzed,and it is concluded that the two-phase winding excitation device has the best excitation performance and the best magnetization uniformity;2.The three-dimensional finite element model of two-phase winding excitation device is constructed,and the shielding layer is introduced to eliminate the influence of stray magnetic field generated by the winding,which significantly improves the uniformity of the device.As the finite element algorithm takes 1-2 hours for each calculation,the adaptive particle swarm optimization algorithm is proposed to improve the convergence speed and calculation accuracy.The structure size of the device is determined by combining the support vector machine algorithm when the sample is magnetized most evenly,which greatly saves time and completes the optimization of the structure of the two-phase winding excitation device.Finally,the excitation winding is designed by analyzing the magnetic circuit of the two-phase winding device and the structural constraints of the cogging device;3.According to the optimized data,a two-phase winding excitation device is set up,and a measurement system is designed.The magnetic field intensity of the sample is measured by placing h coils on the surface of the sample in parallel.However,nanocrystalline materials are fragile.The traditional B coil method needs to drill holes in the sample to measure the magnetic flux density B,so the probe method is used to measure the magnetic flux density B,The probe method only needs to realize the electrical contact on the sample to complete the measurement of magnetic flux density,which improves the accuracy of measurement.Finally,the hysteresis loops and loss characteristic curves of the nanocrystalline alloy in the rolling direction and perpendicular to the rolling direction were measured under the excitation of 10 k Hz high frequency magnetic field.In this paper,we have measured some physical properties and loss characteristics of nanocrystalline materials,which has a guiding role for the optimal design of electrical equipment with nanocrystalline alloy as magnetic core material,and has important theoretical significance for the accurate measurement of high-frequency two-dimensional magnetic properties,to provide data basis and academic support for further accurate analysis of motor and transformer energy consumption. |
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