A Field Reconstruction Technique for Efficient Modeling of the Fields and Forces Within Induction Machines

Abstract

Abstract-Traditional analysis and design of induction machines have been largely based upon lumped-parameter models. An alternative tool used for field-based evaluations of an induction machine is the finite-element method. Although useful, its computational complexity limits its use as a design tool. In this paper, a field reconstruction (FR) method for induction machine simulation is introduced. The FR method utilizes a small number of finite-element evaluations to establish basis functions of normal and tangential flux densities. The basis functions are then used to estimate the magnetic field under arbitrary stator excitation. Using such a tool, evaluation of fields and forces produced by a machine under alternative excitation strategies can be explored efficiently. Moreover, alternative field-based derivation of stator/rotor excitation control can be explored.Index Terms-Field reconstruction (FR), finite element (FE), induction machine, Maxwell stress tensor, torque and radial force.

A Multirate Field Construction Technique for Efficient Modeling of the Fields and Forces Within Inverter-Fed Induction Machines

“…Detailed derivation and explanation are presented in [19]- [21]. The FCT is established based upon the assumption that the machine is operated in the linear magnetic region, which is consistent with the assumption used in many models.…”

“…A so-called field construction technique (FCT) was introduced in [19] to reduce the computational burden of field-based analysis of induction machinery. In the FCT approach, two FEA evaluations are used to determine the normal and tangential components of the flux density in the airgap under single-winding excitation and zero rotor speed.…”

“…The FEA results are then used to establish basis functions of the airgap flux density. Using the basis functions, fields and forces acting inside the machine are predicted under arbitrary stator excitation and rotor speed [19]. In [20] and [21], the current-input-based FCT was extended to enable stator voltage as the model input.…”

“…Using the basis functions, fields and forces acting inside the machine are predicted under arbitrary stator excitation and rotor speed [19]. In [20] and [21], the current-input-based FCT was extended to enable stator voltage as the model input. Therein, so-called flux linkage basis functions are introduced to predict the stator flux linkages under arbitrary voltage excitation.…”

“…The FCTs focused on the modeling of the machine dynamics in [19]- [21]. In this paper, a focus is placed on the coupled modeling of machine/inverter systems.…”