	US 11,790,132 B2
	Calculation method of eddy current loss in magnetic materials based on magnetic-inductance
Ming Cheng, Jiangsu (CN); Zheng Wang, Jiangsu (CN); Wei Qin, Jiangsu (CN); and Xinkai Zhu, Jiangsu (CN)
Assigned to SOUTHEAST UNIVERSITY, Jiangsu (CN)
Appl. No. 17/612,942
Filed by SOUTHEAST UNIVERSITY, Jiangsu (CN)
PCT Filed Jan. 22, 2021, PCT No. PCT/CN2021/073270 § 371(c)(1), (2) Date Nov. 19, 2021, PCT Pub. No. WO2022/110529, PCT Pub. Date Jun. 2, 2022.
Claims priority of application No. 202011357024.4 (CN), filed on Nov. 26, 2020.
Prior Publication US 2022/0366106 A1, Nov. 17, 2022
Int. Cl. G06F 30/23 (2020.01); H01F 41/02 (2006.01); G06F 119/06 (2020.01)

CPC G06F 30/23 (2020.01) [H01F 41/0246 (2013.01); G06F 2119/06 (2020.01)]

4 Claims

1. A calculation method of eddy current loss in magnetic materials, wherein an eddy current reaction is equivalent to a lumped parameter magnetic-inductance L_mc, then a vector model F=Φ·(R_mc+jωL_mc) of a magnetic circuit is established, wherein j is an imaginary unit, R_mcis a reluctance of the magnetic circuit, ω is an angular frequency of a magnetic flux varied in the magnetic circuit, Φ is a magnetic flux vector in the magnetic circuit, and F is a magnetomotive force (MMF) vector in the magnetic circuit; and the calculation method of eddy current loss in magnetic materials comprises the following steps:

S1, an excitation voltage U_Ewith a frequency of f₁is applied to an excitation coil, generating an excitation current İ_E, an induced voltage U_Dis induced on a detection coil, and active power P input to the excitation coil can be observed by a power analyzer;

S2, the magnetic flux vector Φ and a flux density B can be obtained through a relationship-Φ=U_D/(2πf₁N₂), wherein N₂is the number of turns of the detection coil;

S3, a magnetic-inductance L_{mc_1}of the magnetic circuit with the frequency of f₁can be derived by the input active power observed in S1 and a relationship formula of P=ω²L_mc∥Φ∥²;

S4, magnetic fluxes corresponding to different excitation voltages can be obtained in S2 by keeping the frequency of the excitation voltage unchanged while changing amplitude of the excitation voltage U_E; and then the eddy current losses with the different magnetic fluxes can be calculated by the relationship formula of P=ω²L_mc∥Φ∥²; and

S5, a magnetic-inductance L_{mc_2}with a frequency f₂in the magnetic circuit can be obtained according to a formula

therefore, when the frequency of the excitation voltage is adjusted to f₂, then the eddy current losses with the different magnetic fluxes can be obtained as well according to the relationship formula of P=Φ²L_mc∥Φ∥².