Permanent Magnet Electric Motor Research Articles

Comprehensive Multidisciplinary Electric Vehicle Modeling: Investigating the Effect of Vehicle Design on Energy Consumption and Efficiency

In this study, an electric vehicle (EV) dynamic model is devised that amalgamates mechanical design aspects—such as aerodynamic effects, tire friction, and vehicle frontal area—with crucial components of the electrical infrastructure, including the electric motor, power converters, and battery systems. Verification of the model is executed through a comprehensive multidisciplinary analysis utilizing CATIA, ANSYS Electromagnetics, ANSYS Fluent, and MATLAB–Simulink tools, which are applied to evaluate two alternative lightweight EV prototypes. The process involves initial computations of critical inputs for the dynamic model, including aerodynamic lift (C1), drag coefficients (Cd), and frontal area (Af). Subsequent stages entail the detailed design and analysis of a 2 kW brushless permanent magnet electric motor in ANSYS Electromagnetics to map efficiency contours across various speed–torque values. Integration of these parameters into a MATLAB–Simulink dynamic model, connected with motor drive inverter and battery models, allows for simulation-based energy consumption analysis under race track slope profiles. Remarkably, the findings underscore the considerable impact of neglected parameters on energy consumption, often exceeding fifty percent of the total. Consequently, an energy-efficient EV prototype is manufactured and rigorously tested under specified drive conditions, affirming the validation of the comprehensive multidisciplinary EV dynamic model.

Hybrid-electric power unit for an ultralight aircraft

High power-weight ratio, reliability and efficiency are the main design goals for the propulsion system of ultralight aircraft (mass up to 650 kg). For power outputs beyond 40 kW, 4-stroke multi-cylinder SI engines are the most widespread solution, while pure electric powertrains do not appear at the moment as a practical proposition. Four stroke diesel engines would also be very attractive, in particular for military applications, but their weight is significantly higher than their gasoline powered counterpart. The goal of the study presented in this article is to develop a hybrid-electric power unit for ultralights, running on heavy fuels (diesel, kerosene, jet fuels). Reference is made to Falco EVO, by Leonardo, originally equipped by the Rotax 912 ULS/S engine (peak power 73.5 kW, weight about 60 kg): the proposed power unit has the same cylinders layout, smaller overall dimensions and almost equivalent weight. The thermal engine is an innovative two-stroke unit, coupled in parallel to a permanent magnet electric motor. The design and optimization of the hybrid power unit has been supported by CAE tools, including CAD and CFD simulations.The results of the study show that the new hybrid system can save about 30% of fuel mass at the typical cruise conditions, and it can increase the peak power output up to 20%, compared to the reference Rotax engine. The reduction of fuel consumption can be translated into an equivalent increment of the operative range of the aircraft, or into an increase of payload (+30%, considering the Falco EVO aircraft). Finally, compared to the Rotax engine, the hybrid power unit exhibits significantly lower CO2 emissions (from -12% to -37%), thanks to the improvement of fuel efficiency.

Thermal characterization of an interior permanent magnet electric motor

An engineering approach for thermal characterization of an interior permanent magnet electric motor (EM) with a specific aim to identify the interdependency between its mean coil temperature and the maximum component temperatures at the conditions with constant and variable loads/speeds is proposed. For specifying the convective thermal boundary condition between stator and rotor that spins at variable speeds/directions, an experimental study aimed at devising the empirical heat transfer correlation for the Taylor-Couette airflow with varying rotating speed/direction is performed. It is firstly revealed that the responsive air-gap heat convection to angular acceleration follows the characteristic of a single-degree-of-freedom (SDOF) dynamic system. Along with the heat transfer correlation for the unsteady Taylor-Couette airflow, the nonhomogeneous thermal conductivity model that considers the orthogonality effect of the bent coiled winding at its two axial ends is integrated with an iteration scheme for calculating the air bulk temperature in an entrapped air chamber. The favorable experimental validation with the maximum discrepancies between predicted and measured component temperatures less than 7 % in steady and unsteady running conditions affirms the accuracy of the proposed simulation model. At a rotating speed of 4800 rev/min and power output of 1688 W, the maximum-to-mean temperature differences of stator winding, magnetic stripe, and steel sheet of stator reach respectively 6.75 °C, 3.21 °C, and 6.94 °C. Particularly, all the maximum component temperatures are well correlative with the mean temperature of the stator winding at the various steady/unsteady operating conditions. This finding extends the application of lumped thermal network analysis that predicts the averaged components’ temperatures; and enables the on-line monitoring for the maximum component temperatures using a mean stator-winding temperature as the controlling factor.

Diagnosis of material wear on the running track bearing of a synchronous permanent magnet electric motor

This study addresses the issue of creating methods for diagnosing the condition of bearing assemblies using an onboard diagnostic complex of an urban electric bus. The purpose of the study is to identify types of rolling bearing failures in the composition of the traction electric drive of urban route transport and to develop methods for their diagnosis using analysis of phase currents in the windings of the electric motor. As a result of the study, a new mathematical model of resistance torque was developed, and the diagnostic feature value of defect development was established. Thus, this study has practical significance for ensuring the reliability and safety of urban transport, especially under conditions of intensive operation and high loads on the electric drive. Keywords: urban electric transport, diagnostics, bearing assemblies, onboard diagnostic complex, analysis of phase currents, mathematical model, defect

РАЗРАБОТКА И ИССЛЕДОВАНИЯ БЕСКОНТАКТНОГО ЭЛЕКТРОДВИГАТЕЛЯ ДЛЯ БЕСПИЛОТНЫХ ЛЕТАТЕЛЬНЫХ АППАРАТОВ

Relevance Today, there is a growing demand for the unmanned aerial vehicles usage to solve various types of problems. Moreover, unmanned aerial vehicles often designed and manufactured using standard imported components. The creation of electric unmanned aerial vehicles is promising, due to their environmental friendliness and reliability. Such aircraft are based on electric propulsion systems — electrotechnical complexes and systems consisting of an electric motor, an inverter electronic unit and a propeller. Aircraft type electric unmanned aerial vehicles are widespread due to their high range and flight time. Electric motors of aircraft type unmanned aerial vehicles are subject to increased requirements for noise and vibration levels, since the body of aircraft-type unmanned aerial vehicles can act as a resonator. As part of programs to ensure import independence of the Russian Federation, the development and research of electric motors for propulsion systems of electric unmanned aerial vehicles, including aircraft types, are relevant. Aims of research The main aim of the research is to determine the current technical and scientific level of developments in the field of electric motors for unmanned aerial vehicles. Identification of features and trends in research and development in the field of electric motors for unmanned aerial vehicles. Design, manufacture of experimental samples and research a brushless permanent magnet electric motor for unmanned aerial vehicles. Identifying a series of works aimed at developing a methodology for the design and research of electric motors for propulsion systems of unmanned aerial vehicles. Research methods During the design, methods of analytical calculation and computer finite element modeling were used. Experimental research methods were used to validate computer models and determine whether the created electric motor met the required parameters. To conduct experimental studies, a special stand was used with the ability to measure the thrust of the propulsion system. In the future, it is planned to use 3D scanning methods and restore the geometry of propellers for coupled models. Results As a result of the work carried out, an electric motor for aircraft-type unmanned aerial vehicles was developed and researched. Features that must be considered during design were identified. Several works have been identified that will be carried out as part of the design and research of electric motors for unmanned aerial vehicles, aimed at creating a new high-precision interdisciplinary design methodology. The work carried out is the basis for the development of new and scientific approaches to the creation of electric propulsion systems for unmanned aerial vehicles.

Short and long-term mineral resource scarcity impacts for a car manufacturer: The case of electric traction motors

The importance of metals for modern society and future trends puts pressure on companies to handle issues concerning potential mineral resource scarcity (i.e. deficiency in quantity compared with demand). Companies see the need to handle such potential scarcity both in the short-term (is the availability constrained for our current products?) and the long-term (is our current use affecting the availability for future generations?). This study aims to examine the use of complementary methods for short and long-term scarcity in a company context, through a case study on permanent magnet electric traction motors, to provide both empirical and methodological insights. To mitigate long-term scarcity impacts, the results point to copper, neodymium and to some extent dysprosium as priority. These metals contribute to a large share of such impacts both due to themselves and their companion metals. In the short-term, neodymium and dysprosium, which are often regarded as critical (i.e. high supply disruption probability and high vulnerability to supply disruption), were found to be substitutable in the electric motor, reducing their criticality. Instead, the electric motor was most vulnerable to a potential supply disruption of iron and silicon because of no or low substitutability in electrical steel. Methodologically, these perhaps unexpected results, demonstrate that criticality requires a more context-specific assessment than often applied, especially regarding substitutability. By using complementary methods, decision-making about potential mineral resource scarcity impacts in company contexts could become more comprehensive and distinctly address both short and long-term scarcity impacts. • Use of distinct and complementary methods for mineral resource scarcity in company. • Electric motors are most vulnerable to supply disruption of iron and silicon • Electric motors not as dependent on neodymium and dysprosium as can be expected. • Copper, neodymium and their companion metals contribute most to depletion impacts. • Methodological improvements of company-level criticality assessment pointed out.

Development and Performance Measurements of Gas Foil Polymer Bearings with a Dual-Rotor Test Rig Driven by Permanent Magnet Electric Motor

The rotordynamic stability of journal gas foil–polymer bearings (GFPBs) applied to a dual-rotor bearing system was investigated. The GFPB has a high damping structure, i.e., it has an additional polymer layer, and top/bump/bottom foil structures. Test GFPBs were fabricated with nitrile butadiene rubber polymer layers with a thickness of 2 mm. Static-load-deflection tests of test gas foil bearings (GFBs) and GFPBs were performed to estimate the geometric bearing clearance (200 µm). The dual-rotor rotordynamic test rig consisted of a motor rotor, test rotor, and beam-type coupling. Two journal test bearings were installed on both the drive-end and non-drive-end sides of the test rotor. Predicting and testing the natural mode characteristics of the dual rotors revealed that the relative error between them was less than 7%, indicating that the first and second natural frequencies were 15 Hz and 160 Hz, respectively, and the third natural frequency was 1835 Hz in the tests. Based on the API 612 standard, the upper limit of the rotating speed for the test rig was limited to be approximately 92 krpm with a separation margin of 26%. Rotordynamic tests were conducted to examine the stability performance of GFBs and GFPBs, where the adjusted bearing clearance was 150 µm. The test results indicate that GFPBs have better stability performance in terms of delaying and suppressing unstable vibrations than GFBs. Specifically, GFPBs showed stable synchronous and subsynchronous responses up to a maximum rotating speed of 80 krpm. As a result, GFPB is a reliable lubricating element that can be used for vibration dampening in machines operating at relatively low temperatures.

Performance and operability of an electrically driven propulsor

This manuscript discusses the operation of an electrically driven fan for a hybrid-electric propulsion system for BAe-146 aircraft. The thrust requirement is fed into an integrated cycle and aerodynamic design tool for the sizing of a ducted fan as one of the main propulsors, podded under the wing as a replacement for a turbofan engine. The electric motor design is initiated with the torque and speed requirements and with the dimensional constraints arising from the driven fan geometry. The fan operation and aerodynamic design are derived by changing the fan pressure ratio and hub-to-tip ratio to obtain a 2-D design space. Surface-mounted permanent magnet electric motor designs are mapped on the 2-D fan design space. The design and operational flexibility of the system is investigated through three scenarios. In the first scenario, the aircraft rate of climb is changed to downsize the electric motor. In the second scenario, the electric motor rated frequency is changed to increase the power density and in the third scenario the electric motor current density is changed for the same purpose. The investigated three scenarios provide design and operational guidelines for reducing the weight of the electric motor for a direct drive application.

Efficiency Improvement of Permanent Magnet BLDC Motors for Electric Vehicles

A permanent magnet Brushless DC (BLDC) motor has been designed with different rotor configurations based on the arrangement of the permanent magnets. Rotor configurations strongly affect the torque and efficiency performance of permanent magnet electric motors. In this paper, different rotor configurations of the permanent magnet BLDC motor with parallel the Halbach array permanent magnet were compared and evaluated. Many applications of electric drives or air-crafts have recently preferred the surface-mounted permanent magnet design due to its ease of construction and maintenance. The finite element technique has been used for the analysis and comparison of different geometry parameters and rotor magnet configurations to improve efficiency and torque performance. A comprehensive design of a three-phase permanent magnet BLDC 35kW motor is presented and simulations were conducted to evaluate its design. The skewing rotor and Halbach magnet array are applied to the permanent surface-mounted magnet on the BLDC motor for eliminating torque ripples. In order to observe the skewing rotor effect, the rotor lamination layers were skewed with different angles and Halbach sinusoidal arrays. The determined skewing angle, the eliminated theoretically cogging torque, and the back electromotive force harmonics were also analyzed.

ПОРІВНЯЛЬНИЙ АНАЛІЗ МАГНІТНИХ СИСТЕМ ЕЛЕКТРОДВИГУНІВ З ПОСТІЙНИМИ МАГНІТАМИ ДЛЯ ТРАМВАЯ

A numerical study of eight configurations of magnetic systems of electric motors with permanent magnets for driving a tram was carried out. The permanent magnet electric motor can be used as a high-speed electric drive to replace the existing DC electric drive of a tram, and as a low-speed gearless electric drive of a new generation tram. The most promising configurations of magnetic systems of electric motors with permanent magnets for tram drive have been determined. By varying the geometrical and winding parameters of each of the investigated models of electric motors, the mechanical characteristics are determined, at which the given torque and power are achieved in the entire range of the rotor speed. Also, a thermal calculation was performed taking into account the urban driving cycle of high-speed electric motors with air cooling by a fan and low-speed ones in liquid cooling mode. The calculation of the characteristics of the investigated electric motors was carried out in the Simcentre MotorSolve software package. References 13, figures 8, tables 3.

MAIN CHARACTERISTICS ELECTRIC VIBRATORS BASED ON A LINEAR MOTOR WITH PERMANENT MAGNETS

The design of an electric vibrator created on the basis of a linear motor with permanent magnets is considered, and the calculation of the magnetic field and the electromagnetic force acting on the motor armature is performed by the finite element method. The results of experimental studies confirming the reliability of the obtained calculated data are presented]. The purpose of this work is to study the distribution of the magnetic field and the electro-magnetic forces in a coaxial-linear permanent magnet electric motor (PM), which is the basis for the creation of avibration installationKeywords: vibration, magnets, magnetic induction, stator winding, electric vibrator

Reduction of Ripple Toothed Torque in the Internal Permanent Magnet Electric Motor by Creating Optimal Combination of Holes in the Rotor Surface Considering Harmonic Effects

Due to the widespread use of electric motors in various industries, it is very important to have optimally designed motors in that they have high efficiency and lower negative effects on the quality of the power grid. Therefore, in this paper, the effects of winding type (wide and concentrated) on ripple torque in internal permanent magnet motor (IPMM) are investigated. In order to reduce the ripple torque and to increase the average torque, by making optimal holes in the rotor surface and using the sensitivity analysis method, the structure of the IPMM is improved. In this method, the number, dimensions and location of holes are optimized using the sensitivity analysis approach, which reduces the ripple torque of the motor. Using a concentrated winding instead of a wide winding, the toothed ripple torque is reduced by approximately 75% while maintaining the average torque value. Also, by making holes in the rotor surface and optimizing them using the finite element technique and sensitivity analysis, it is demonstrated that the amount of ripple torque by 20%. In the proposed approach, it is proved that in the concentrated winding, in addition to reducing the spatial harmonics, the average amount of torque can also be improved. Obtained results of the simulation confirm the effectiveness of the proposed method.

An Application of the ECMS Strategy to a Wankel Hybrid Electric UAV

In a previous work, the authors optimized the hybrid electric power system for a tactical Unmanned Aerial Vehicle including a Wankel engine as thermal converter and a permanent magnet electric motor powered by lithium batteries. Startingfrom this optimal configuration, we address here the topic of a refined optimization of the energy management strategy, i.e. the contribution of the battery to the required power in each segment of the flight. The Equivalent Consumption Minimization Strategy (ECMS) was chosen with the goal of minimizing fuel consumption while fully depleting the energy stored in the battery from the beginning to the end of each mission.

Life cycle assessment of permanent magnet electric traction motors

Ongoing development of electrified road vehicles entails a risk of conflict between resource issues and the reduction of greenhouse gas emissions. In this study, the environmental impact of the core design and magnet material for three electric vehicle traction motors was explored with life cycle assessment (LCA): two permanent magnet synchronous machines with neodymium-dysprosium-iron-boron or samarium-cobalt magnets, and a permanent magnet-assisted synchronous reluctance machine (PM-assisted SynRM) with strontium-ferrite magnets. These combinations of motor types and magnets, although highly relevant for vehicles, are new subjects for LCA. The study included substantial data compilation, machine design and drive-cycle calculations. All motors handle equal take-off, top speed, and driving conditions. The production (except of magnets) and use phases are modeled for two countries – Sweden and the USA – to exemplify the effects of different electricity supply. Impacts on climate change and human toxicity were found to be most important. Complete manufacturing range within 1.7–2.0 g CO2-eq./km for all options. The PM-assisted SynRM has the highest efficiency and lowest emissions of CO2. Copper production is significant for toxicity impacts and effects on human health, with problematic emissions from mining. Resource depletion results are divergent depending on evaluation method, but a sensitivity analysis proved other results to be robust. Key motor design targets are identified: high energy efficiency, slender housings, compact end-windings, segmented laminates to reduce production scrap, and easy disassembly.

Development and validation of an integrated planetary gear set permanent magnet electric motor power loss model

Abstract This study proposes a methodology to predict power losses of traction motor having an integrated planetary gear set permanent magnet electric motor, including both load-dependent and load-independent power loss components. The methodology combines a planetary gear set loss model which accounts for sliding and rolling losses at the external and internal gear mesh contact interfaces, a bearing mechanical and drag loss model, a gear drag loss model, an external and internal gear mesh pocketing loss model, a permanent magnet synchronous machine iron, and copper loss model. Power loss measurements from a developed prototype traction motor having integrated planetary gear set permanent magnet electric motor is compared to model predictions to successfully demonstrate the accuracy of the proposed methodology.

Design and Optimization of a High Power Density and Efficiency Boost PFC

Nowadays electrical appliances have been becoming more and more popular every day in our life, and the systems that have more power density and that use energy efficiently and that improve the quality of the energy are required more. Especially with the decisions and regulation changes of the United States and the European Union in recent years, it has become compulsory to replace low efficiency electric motor drive systems with high efficiency permanent magnet electric motors and drivers, and as a result permanent magnet motors that have high efficient field orientation control algorithms technologies have begun to be chosen. Low cost uncontrolled rectifiers that have high power factor have become a necessity with the need for DC bus. In such systems with inherently nonlinear characteristics, the need for Power Factor Correction (PFC) circuit has been increasing, and Boost PFC (BPFC) which increase the input voltage are widely preferred for low/medium power applications. Therefore, distortion harmonics and high frequency noises are reduced according to standards such as CSRIP Class B – TS EN 61000-3-2 and also output voltage remains constant, becoming more than peak amount of the input grid voltage. In that study, it is designed that BPFC that has 1,150W output power level by increasing system's power density and efficiency. The system cost is reduced by decreasing the requirement of EMI filters and heatsink size, since using SiC (Silicon Carbide) diode and optimizing the system contribute increasing efficiency and power density. The most efficient Boost PFC design is realized at the lowest cost by performing detailed design, loss and cost analysis for each component used. The Boost PFC with full system efficiency of 95.5% at full load is obtained by model validation done by comparing the simulation results with the experimental results obtained by hardware implementation.

Optimally Segmented Permanent Magnet Structures

We present an optimization approach that can be employed to calculate the globally optimal segmentation of a 2-D magnetic system into uniformly magnetized pieces. For each segment, the algorithm calculates the optimal shape and the optimal direction of the remanent flux density vector, with respect to a linear objective functional. We illustrate the approach with results for magnet design problems from different areas, such as a permanent magnet electric motor, a beam-focusing quadrupole magnet for particle accelerators, and a rotary device for magnetic refrigeration.

Topology Optimization of Electric Motor Using Topological Derivative for Nonlinear Magnetostatics

We aim at finding an optimal design for an interior permanent magnet electric motor by means of a sensitivity-based topology optimization method. The gradient-based ON/OFF method has been successfully applied to optimization problems of this form. We show that this method can be improved by considering the mathematical concept of topological derivatives (TDs). TDs for optimization problems constrained by linear partial differential equations (PDEs) are well understood, whereas little is known about TDs in combination with nonlinear PDE constraints. We derive the TD for an optimization problem constrained by the equation of nonlinear 2-D magnetostatics, illustrate its advantages over the sensitivities used in the ON/OFF method, and show numerical results for the optimization of an interior permanent magnet electric motor obtained by a level-set algorithm, which is based on the TD.

Intelligent Belt Drive Systems in Hybrid Powertrains: a Multipurpose Test Rig

Abstract: In traditional engine setups Belt Drive Systems (BDS) are in charge of power transmission from the crankshaft to the accessories. They are complex and critical dynamic mechanisms, involving contact mechanics and vibration phenomena. The hybridization of vehicles has increased the severity of the operating conditions of these systems that have become even more critical. The traditional alternator was substituted by a Belt-Starter Generator (BSG), an electric machine that can power the BDS in particular operating conditions to improve the Internal Combustion Engine (ICE) performance or to allow regenerative braking. The aim of the present work is to describe the design and the main characteristic of a test rig conceived to investigate in laboratory environment on the behaviour of belt drive systems in dynamic conditions. Two permanent magnet electric motors are used to replicate the dynamic behavior of crankshaft and BSG in a realistic, though controlled and repaetable, manner.

Construction and design features of permanent magnet electric motors for general industrial purposes

Issues of permanent magnet synchronous motor with a fractional slot winding design are discussed in this paper. Fractional slot concentrated windings are windings with less than one slot per pole and phase. This type of winding has the following features. A machine with such a winding has manufacturing advantages, since there are no conductors overlapping at the winding ends; consequently, the manufacturing process is simpler and there is a higher level of reliability. This kind of winding also allows one to create multipole machines of relatively small dimensions. In turn, this makes it possible to increase the stator inner diameter and torque density by reducing the stator yoke. Features of the construction solutions are considered. Means of development and solutions used, as well as methods of calculation and simulation, are described. Experimental results are given. The developed motor is compared with similar induction motors, and the advantages of the synchronous machine are presented.