Estimation of temperature dependent equivalent circuit parameters for traction-based electric machines

Abstract

Copyright © and Moral Rights are retained by the author(s) and/ or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This item cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder(s). The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders. CURVE is the Institutional Repository for Coventry University AbstractThe influence of temperature conditions on electric machine models is not well understood. This paper investigates modelling the temperature dependence of equivalent circuit parameters. Experiments have been performed on an induction machine to characterise its impedance response (up to 10 MHz) over the temperature range (22.4-210) o C. Using these measurements non-linear parameter estimation is performed using the Nelder-Mead method to derive temperature-dependent models, with an average absolute magnitude error of 270 Ω. The accuracy has been evaluated over the frequency range for the different temperatures and highlights where improvements are needed. This work has important applications in electric machine design and condition monitoring. Also it provides a valuable precursor towards developing age-dependent models for traction based applications.

Equivalent circuit model estimation of induction machines under elevated temperature conditions

“…Temperature increases within the stator windings result in increase in copper resistivity [21] and change in thickness of insulator between stator windings which affects turn to turn winding capacitance [22]. This paper extends on previous work by the authors [23], where an initial study of temperature-dependent parameters estimation of ECMs was conducted. The model structure proposed in [16] was found to be adequate for modelling motor frequency characteristics up to (130) o C. Studies of Mirafzal et al [16] suggest that some parameters can be estimated accurately using only low frequency data and have a negligible effect at higher frequencies.…”

Modelling and Stability Analysis of Brushless Doubly Fed Generators

“…Further simulations have been conducted to study the impact of electric parameters changes on the machine stability. Particular interest has been given on the effect of variations in rotor's resistance r R and self-inductance r L , as these parameters can undergo significant variations with rotor's temperature increase during machine operation [21][22]. The variation of a parameter x can be expressed as:…”

Thermal Degradation Phenomena of Polymer Film on Magnet Wire for Electromagnetic Coils

“…In this context, the impact of water ingress on electrically stressed stator coils [9], accelerated ageing on wound model subsections of machines [4], the ageing of calendered insulation paper for for transformers [21] and the impact of fast switching of power electronic converters on insulation health [22], [23] have all been investigated. Suitable techniques for characterising and modelling insulation in terms of physical, chemical, dielectric and electrical properties are immensely valuable for quality assessment, diagnostics and degradation analysis to determine state of health and also for creating equivalent circuit models [24], [13], [25] for thermal analysis. Related approaches in the literature have investigated ageing on twisted insulation-coated wire pair set-ups [23], [26], motorettes or coils [27], [4] or even full machines [28], [29], [24], [25].…”

“…Suitable techniques for characterising and modelling insulation in terms of physical, chemical, dielectric and electrical properties are immensely valuable for quality assessment, diagnostics and degradation analysis to determine state of health and also for creating equivalent circuit models [24], [13], [25] for thermal analysis. Related approaches in the literature have investigated ageing on twisted insulation-coated wire pair set-ups [23], [26], motorettes or coils [27], [4] or even full machines [28], [29], [24], [25]. The complexity of such setups and the coupled multifaceted ageing phenomena (TEAM) makes the analysis extremely difficult to interpret.…”