Calculation Method of Magnetic Force of Hybrid Electromagnets Based on Nonlinear Inductance
In order to improve the accuracy and efficiency of the magnetic force calculation of hybrid electromagnets,this paper took into account the advantages of fast calculation speed of the analytical method and high calculation accuracy of the finite element method and proposed a calculation method of the magnetic force of hybrid electromagnets based on the nonlinear inductance.The paper first analyzed the relationship between the inductance and current of the hybrid electromagnet and established a nonlinear inductance model considering magnetic saturation.Then,the equivalent surface current method was used to equate two typical hybrid electromagnet structures(structure a,structure b)into pure electromagnet structures with multi-electromagnetic coils.The magnetic force expression of the series magnetic circuit type hybrid electromagnet was derived by using the energy balance method,in which the parameter variables of the nonlinear inductance model were fitted by the finite element simulation method.The research results show that the average deviations between the electromagnetic force calculation results of structures a and b obtained by the proposed method and the traditional finite element simulation are 2.54%and 2.37%,and the average deviation between structure a and experimental measurement is 2.63%.Compared with the traditional finite element method,the calculation efficiency is greatly improved.In other words,the proposed method obtains electromagnetic force calculation results that are much more accurate than the existing analytical formulas through finite element simulation with fewer tasks.
hybrid electromagnetnonlinear inductanceenergy balance methodfinite element methodmagnetic force calculation