649 research outputs found
Thermal performance analysis of the double sided-linear switched reluctance motor
This paper presents an exhaustive study about the propulsion force and the thermal performance of the double-sided flat Linear Switched Reluctance Motor (LSRM) according to the number of phases (m) and the pole stroke (PS). The analysis is performed by means of the Finite Element Method (FEM) for electromagnetic computations and a lumped parameter for thermal model (LPT) both linked to an optimization algorithm based on the Response Surface Methodology (RSM) in order to reduce the computing time. The results show the optimal design of LSRM from the point of view of the thermo-mechanical performance for a given insulation class and a duty cycle operating conditions
Advanced lumped parameter model for switched reluctance motors with high performance cooling
In this paper an advanced thermal lumped parameter model for a switched reluctance electric motor (SRM) is constructed, based on a 2D thermal finite element simulation of a radial cross section of the motor. When applying and combining advanced cooling methods such as direct coil cooling, end winding cooling (radial stretched) and spray cooling on an SRM, the conventional lumped parameter models can no longer be used due to the 3D and complex temperature gradients in the motor. In standard LP models, mostly one simple cooling method is implemented by which the thermal gradients are also quite simple (1D or 2D). When combining different cooling methods, the gradients become highly 3D and these LPM are no longer valid. To improve the accuracy of this problem, a fully 3D thermal finite element simulation could be performed, but this would unnecessarily increase effort, complexity and computational time. To avoid this an advanced lumped parameter model is constructed in this paper, such that the high thermal gradients are modeled in more detail. The results from one 2D finite element simulation of a radial cross section of half of a stator tooth are reduced to a simpler lumped parameter model with more nodes in the most crucial parts, i.e., where the highest thermal gradients are expected. The 2D thermal model is then expanded to a 3D lumped parameter model, including the gradients in axial direction. Using this model, various cooling configurations and geometry parameters can be varied easily such that the design of an SRM with advanced cooling can be optimized efficiently
Synchronous reluctance motors with fractional slot-concentrated windings
PhD ThesisToday, high efficiency and high torque density electrical machines are a growing research
interest and machines that contain no permanent magnet material are increasingly sought.
Despite the lack of interest over the last twenty years, the permanent magnet-free synchronous
reluctance machine is undergoing a revival and has become a research focus due
to its magnet-free construction, high efficiency and robustness. They are now considered a
potential future technology for future industrial variable speed drive applications and even
electric vehicles. This thesis presents for the first time a synchronous reluctance motor
with fractional slot-concentrated windings, utilizing non-overlapping single tooth wound
coils, for high efficiency and high torque density permanent magnet-free electric drives.
It presents all stages of the design and validation process from the initial concept stage
through the design of such a machine, to the test and validation of a constructed prototype
motor. The prototype machine utilizes a segmented stator core back iron arrangement for
ease of winding and facilitating high slot fill factors. The conventional synchronous reluctance
motor topology utilizes distributed winding systems with a large number of stator
slots, presenting some limitations and challenges when considering high efficiency, high
torque density electrical machines with low cost. This thesis aims to present an advancement
in synchronous reluctance technology by identifying limitations and improving the
design of synchronous reluctance motors through development of a novel machine topology.
With the presented novel fractional slot concentrated winding machine design,
additional challenges such as high torque ripple and low power factor arise, they are explored
and analysed - the design modified to minimise any unwanted parasitic effects.
The electrical and electromagnetic characteristics of the developed machine are also explored
and compared with that of a conventional machine. A novel FEA post-processing
technique is developed to analyse individual air-gap field harmonic torque contributions
and the machines dq theory also modified in order to account for additional effects. The
developed machine is found to be lower cost, lower mass and higher efficiency than an
equivalent induction or conventional synchronous reluctance motor, but does suffer higher
torque ripples and lower power factor. The prototype is validated using static and dynamic
testing with the results showing a good match with finite element predictions. The work
contained within this thesis can be considered as a first step to developing commercial
technology based on the concept for variable speed drive applications.Financial assistance was provided by was provided by the
UK Engineering and Physical Sciences Research Council (EPSRC) in the form of a Doctoral
Training Award and additional financial assistance was kindly provided by Cummins
Generator Technologies, Stamford, UK, through industrial sponsorship of this wor
Influence of design parameters in the optimization of linear switched reluctance motor under thermal constraints
The objective of this paper is to present an
original study for optimizing the size of the LongitudinalFlux
Double-Sided Linear Switched Reluctance Motor
(LSRM) under thermal and weight constraints. The
performance is evaluated taken into account duty cycle
operating conditions and thermal restrictions. The
proposed approach couples Finite Element Analysis for
magnetic propulsion force computation and Lumped
Parameter Thermal Network for thermal transient analysis.
The LSRMs design parameters are characterized by the
number of phases and by their size denoted by the pole
stroke. The operating conditions are the current density,
the duty cycle and the admissible temperature rise of the
insulation system. The grid search algorithm is used for
solving the optimization problem. From the results, with
the help of a novel multivariable optimization chart, a set
of optimal configurations regarding to miniaturizations
and downsizing of LSRMs is provided.Peer ReviewedPreprin
Modelling and Control of Switched Reluctance Machines
Today, switched reluctance machines (SRMs) play an increasingly important role in various sectors due to advantages such as robustness, simplicity of construction, low cost, insensitivity to high temperatures, and high fault tolerance. They are frequently used in fields such as aeronautics, electric and hybrid vehicles, and wind power generation. This book is a comprehensive resource on the design, modeling, and control of SRMs with methods that demonstrate their good performance as motors and generators
Modelling and Control of Switched Reluctance Machines
Today, switched reluctance machines (SRMs) play an increasingly important role in various sectors due to advantages such as robustness, simplicity of construction, low cost, insensitivity to high temperatures, and high fault tolerance. They are frequently used in fields such as aeronautics, electric and hybrid vehicles, and wind power generation. This book is a comprehensive resource on the design, modeling, and control of SRMs with methods that demonstrate their good performance as motors and generators
An innovative natural air-cooling system technique for temperature-rise suppression on the permanent magnet synchronous machines
Peer ReviewedPostprint (author's final draft
Overview of Sensitivity Analysis Methods Capabilities for Traction AC Machines in Electrified Vehicles
© 2021 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/.A robust design in electrified powertrains substantially helps to enhance the vehicle's overall efficiency. Robustness analyses come with complexity and computational costs at the vehicle level. The use of sensitivity analysis (SA) methods in the design phase has gained popularity in recent years to improve the performance of road vehicles while optimizing the resources, reducing the costs, and shortening the development time. Designers have started to utilize the SA methods to explore: i) how the component and vehicle level design options affect the main outputs i.e. energy efficiency and energy consumption; ii) observing sub-dependent parameters, which might be influenced by the variation of the targeted controllable (i.e. magnet thickness) and uncontrollable (i.e. magnet temperature) variables, in nonlinear dynamic systems; and iii) evaluating the interactions, of both dependent, and sub-dependent controllable/uncontrollable variables, under transient conditions. Hence the aim of this study is to succinctly review recent utilization of SA methods in the design of AC electric machines (EM)s used in vehicle powertrains, to evaluate and discuss the findings presented in recent research papers while summarizing the current state of knowledge. By systematically reviewing the literature on applied SAs in electrified powertrains, we offer a bibliometric analysis of the trends of application-oriented SA studies in the last and next decades. Finally, a numerical-based case study on a third-generation TOYOTA Prius EM will be given, to verify the SA-related findings of this article, alongside future works recommendations.Peer reviewe
Thermal modeling of a mini rotor-stator system
In this study the temperature increase and heat dissipation in the air gap of a cylindrical mini rotor stator system has been analyzed. A simple thermal model based on lumped parameter thermal networks has been developed. With this model the temperature dependent air properties for the fluid-rotor interaction models have been calculated. Next the complete system has also been modeled by using computational fluid dynamics (CFD) with Ansys-CFX and Ansys. The results have been compared and the capability of the thermal networks method to calculate the temperature of the air between the rotor and stator of a high speed micro rotor has been discussed
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