Eddy-Current Field Analysis in Laminated Iron Cores Using Multi-Scale Model Order Reduction

Abstract

This paper develops a multi-scale Model Order Reduction (MOR) method including both material and machine scale MOR. The material-scale MOR homogenizes the eddy-current (EC) field in laminated cores using the Legendre expansion of magnetic induction along the stacking direction within each steel sheet. The machine-scale MOR represents the EC field in electromagnetic devices with their equivalent Cauer Ladder Network (CLN). The former MOR is built into the latter by applying the CLN procedure to the homogenized EC field equation.

Nonlinear Multi-Scale Model Order Reduction of Eddy-Current Problems

“…The multi-scale MOR in section III was first presented in [10], where the homogenization and the CLN were both limited to the linear magnetic materials. In many practical electromagnetic apparatus, the core is operated under saturation.…”

“…Some of the MOR approaches are capable of generating equivalent circuit models such as Padé via Lanczos (PVL) approximation to Krylov subspace [6] or the Cauer Ladder Network (CLN) method [7]. Several extensions were proposed to the CLN method, including nonlinear CLN [8], [9] and multi-scale MOR [10], [11]. The multi-scale MOR combines the homogenization method as a microscopic MOR and the CLN method as a machine scale MOR to construct an efficient and accurate reduced system including the laminated core [10].…”

“…Several extensions were proposed to the CLN method, including nonlinear CLN [8], [9] and multi-scale MOR [10], [11]. The multi-scale MOR combines the homogenization method as a microscopic MOR and the CLN method as a machine scale MOR to construct an efficient and accurate reduced system including the laminated core [10].…”

Modal Analysis of an 8/6 Pole Switched Reluctance Motor Core with Different Materials and Assembly Method Using FEA

“…(2) It can loosen windings and cause mechanical damage to insulation by fracturing, flaking, or eroding of the material. (3) The excessive movement can generate high temperature, and as a result, the lead wires can become brittle. The mechanical causes of the electromagnetic force [1] are primarily the air gap eccentricity between the stator and the rotor.…”

“…These laminations can be stacked "loose", welded, or bonded together depending on the application. Laminations sheets are used instead of a solid piece to reduce eddy current losses [3][4].…”