Revisited Magnetic Equivalent Circuit Method for Predicting the Characteristics of Highly Saturated Electromagnetic Devices: Flux Ratio Criterion Technique

摘要

To model nonlinear magnetic fields inelectromagnetic devices using Magnetic Equivalent Circuit (MEC) method as a numerical method, flux tubes in frame of permeance elements are commonly used to represent flux distribution pattern everywhere within the device. The accuracy of the method depends on the geometric shapes attributed to flux tubes, particularly in highly saturated regions. Although it is possible to take a nearly correct graphical shape for each tube in these regions, the size of the tube cross section will be remained unknown because of ambiguity in the actual lateral extent of the flux flowing through the tube. This paper examines the problem and presents a technique, here called Flux Ratio Criterion (FRC), which helps to determine each tube cross section during solving the nonlinear matrix equation of the circuit. The proposed technique is applied to predict the characteristics of a Switched Reluctance Machine (SRM). The results are compared with those obtained from FEM, and measurements.