Finite reluctance approach: A systematic method for the construction of magnetic network-based dynamic models of electrical machines

Abstract

The finite reluctance approach is based on a simple synergy between a basic magnetic domain decomposition rule and the voltage balance at the terminals of any winding acting in the domain. The finite reluctance approach is thought as a tool for fast dynamic simulations of any kind of machine, but it is particularly adapt for irregular flux geometries as in fractional-slot surface-mounted permanent magnet machines with large slots and high slot flux leakages, for which only the finite element method has found good usage. This approach is based on the definition of a complementary mesh interlaced with the reluctance mesh, on the concept of material cell, and on unique rules to carry out both reluctances and magneto-motive forces. At this scope, definitions of mesh nodes, co-nodes, and auxiliary nodes are shown. The iron saturation can be easily taken in account, as well as motion effects. The circuit flux linkages are elected as state variables for integration, and they are directly linked to the loop fluxes in the magnetic network. The finite reluctance approach has been applied in this paper for dynamic modeling of an inverter-fed permanent-magnet linear synchronous motor

Validation of a magnetic network-based dynamic model of permanent magnet linear synchronous machine built by finite reluctance approach

“…III. RESUME OF THE FINITE RELUCTANCE METHOD Only a fast resume of the theory of paper [1] is given here, for commodity of the reader. The reader will find in [1] a more complete treatise about the FRA method.…”

“…he finite reluctance approach (FRA) has been recently introduced and detailed in [1]. The FRA takes inspiration from a more general theory about the finite formulation of electromagnetic field, developed by Tonti [2].…”

“…The theory in [2] is based on the concept of 'cell' as basic element for the decomposition of a given magnetic domain. Paper [1] exploits the concept of cell for a practical implementation in the framework of a finite-reluctance-based approach to the construction of magnetic networks useful for electrical machine dynamic simulations.…”

“…The discussion of all these aspects and their solution by FRA is presented in [1]. This paper instead shows dynamic simulations of a particular permanent magnet linear synchronous machine (PMLSM) designed for on board ship steering [8].…”

Electromagnetic Modeling Techniques for Switched Reluctance Machines: State-of-the-Art Review

“…The MEC technique is usually utilized to provide preliminary designs [92][93][94][95] and to analyze the electromagnetic characteristics [91], [96], [97] of SRMs. This technique is divided into two approaches: conventional MEC approach [98][99][100] and reluctance-mesh/finite-reluctance approach (FRA) [101][102][103][104].…”