This paper presents the effect of in-wheel motor (IWM) suspension system on electric vehicle (EV) ride comfort. To analyze the impact on the vehicle ride comfort caused by IWM suspension system, a ...dynamic model of quarter vehicle is established with the combination of IWM and road surface roughness excitations. The weighted root-mean-square (r.m.s.) acceleration of the vertical vehicle body ( a w b z ) according to the international standard ISO 2631-1 (1997) is selected as an objective function to analyze the effect of IWM suspension system when the road surface and IWM mass conditions change. The study results indicate that the effect of IWM suspension system on the EV ride quality is significant and the value of a w b z reduces by 8.6 % in comparison to without IWM suspension system. The IWM suspension system has significantly improved the EV ride quality when the road surface and IWM mass conditions change.
Brushless DC motor has specifications such as high efficiency, high startup moment and silent running. Thanks to its low inertia, high torque/size and power/size ratio, it can be used in specially ...designed vehicles such as electric vehicles (EVs), spacecraft and submarines. As there is no brush and commutator that in its structure can cause arc forming, it can be used in fire-sensitive areas. In this study, a 2 kW three-phase out-runner permanent magnet brushless DC (BLDC) motor was designed to be used in ultralight EV. The size of the motor, the magnetic equivalent circuit and the electrical equivalent circuit parameters required for the BLDC motor design process were analytically calculated. The finite element method was then used to evaluate flux density, flux distributions, torque and motor efficiency and was approved for analytical design. The BLDC motor, which has about 89% efficiency, has been manufactured and mounted on an ultralight EV. Finally, the motor speed was estimated using a new robust hybrid metaheuristic model called artificial neural networks (ANNs) trained with particle swarm optimization (PSO) and radial movement optimization (RMO). A genuine and unconventional technique was used to examine the model's performance. That is, using three distinct input variables such as output torque, efficiency and output power, the output variable of motor speed was estimated. And then, the results were compared using the other three hybrid models. In all performs, it was seen that ANNs trained with PSO + RMO model achieved the most successful results with the lowest errors.
In-wheel direct drive motors are placed inside drive wheels of electric vehicles and have to deliver large torque without any mechanical gear. Most often these machines are of synchronous type with ...permanent magnets and large pole-pair number. As a consequence of high peak torque, both cogging torque and torque ripple are increased if no measures are taken to decrease them. The vibrations due to cogging torque and torque ripple result in noise and reduced motor durability. In this paper, analytical equations and finite element method are derived, developed and used in order to analyse the dependence of cogging torque on magnet shape and size. A novel magnet shape is found that eliminates cogging torque without reducing the motor torque constant or increasing magnet size. The shape is applicable to any surface mounted permanent magnet motor with high number of pole pairs.
This paper studies electromagnetic and parametric design and performance analysis of an in-wheel out-runner BLDC (Brushless Direct Current) electric motor designed specifically for automotive ...applications. Typical design techniques and simulation studies are applied to the BLDC motor. Specifically, design specifications such as the number of turns, winding area, and stator pole height composing the stator structure are obtained and the performance characteristics of the motor are investigated using the finite element method (FEM). Also, the outputs in terms of phase inductances, flux linkages of each stator winding and static torques for different rotor positions are calculated and evaluated. Finally, a dynamical performance analysis is carried out by using a physical electromechanical model the BLDC motor.
Analysis of a three-phase in-wheel electric motor Luque, D.; Ruppert, E.; Bianchi, N. ...
2009 44th International Universities Power Engineering Conference (UPEC),
2009-Sept.
Conference Proceeding
This paper presents the analytical study, finite element model, and experimental tests on a three-phase surface-mounted permanent magnet (SPM) synchronous motor designed for the wheel of a hybrid ...vehicle. The paper focuses on the machine design process so as to achieve the maximum torque-to-current and torque-to-volume ratio. Combining finite element simulations and analytical model, the final solution is obtained as a compromise between conflicting values. The measurements on a SPM motor prototype confirm the results obtained by means of the developed analysis.
In this paper we study the effects of increased unsprung mass that result from the use of in-wheel electric motors used in hybrid and/or electric drive trains. For this purpose we reduce the problem ...to the analysis of the quarter car suspension model to assess how increasing unsprung mass affects the ride comfort. In order to see the change in the ride comfort level according to ISO 2631 the analysis was done in frequency domain using random road profile inputs generated according to ISO 8608. Also the results were assessed using a commercial multi body vehicle simulation software. Finally we suggest empirical solutions regarding modified suspension and tire parameters to compensate the detrimental effects of increased unsprung mass.
L'objectif principal de cette thèse est l'étude de l'exploitation de systèmes moteurs-roues (machines électriques intégrées à la roue) pour le contrôle de la dynamique véhicule. Cette thèse est issue ...d'un co-financement (numéro 186-654, 2010-2013) entre le Laboratoire des Signaux et Systèmes (CNRS) et l'Institut Français du Pétrole et Énergies Nouvelles (IFPEN). Les avantages apportés par l'utilisation du moteur électrique sont avérés et de nouvelles techniques de contrôle sont développées pour optimiser son utilisation. Les lois de contrôle basent généralement sur la grandeur principale du moteur électrique: le couple transmis, qui peut être mesuré via le courant consommé. Une autre caractéristique importante du moteur électrique est son temps de réponse, avec le fait qu'il peut produire des couples négatifs, pour ralentir le véhicule, tout en stockant l'énergie. La nouveauté du présent travail est de considérer le moteur-roue électrique comme seul signal de contrôle dans des phases d'accélération et des phases de ralentissement, simplifiant l'architecture de la conception du véhicule et des lois de contrôle. Pour répondre à la demande conducteur tout en préservant un comportement sain du véhicule, des stratégies d'estimation de la limite d'adhérence seront présentées. En fonction de cette adhérence maximale disponible entre la route et les pneus, un couple adéquat sera calculé pour assurer un comportement stable dans des phases d'accélération aussi bien que de freinage. L'aspect critique étudié dans ce travail est la non-linéarité des caractéristiques d'interaction entre la route et le pneu et la complexité de son estimation dans des conditions variables. La stratégie d'estimation devra détecter tous les changements d'adhérence de route et la loi de contrôle calculée devra maintenir la stabilité véhicule même lorsque la friction maximale change. Certaines formes de perturbation et de bruit seront également prises en compte afin de tester la robustesse des approches d'estimation et de contrôle proposés. Parmi les systèmes de sécurité active les plus importants en phase d'accélération, le système de contrôle de traction (TCS) rétablit la traction si les roues commencent à patiner et le programme de stabilité électronique (ESP) intervient pour prévenir une perte menaçante du contrôle latéral du véhicule. Dans le cas du freinage, le système décisif est le système d'antiblocage (ou ABS), qui empêche le blocage des roues. On peut trouver d'autres systèmes embarqués, comme le système de distribution de force de freinage électronique (EBD), qui assure une distribution optimale de la force de freinage transmise aux roues, pour éviter de déraper et assure un ralentissement stable du véhicule. Les systèmes embarqués qui fournissent les estimations doivent être robustes aux bruits de mesure et aux perturbations. A fortiori, ces calculs doivent être faits en temps réel, donc une complexité réduite et une réponse rapide de la loi de contrôle sont nécessaires. Enfin, l'environnement dans lequel le véhicule fonctionne est dynamique, les caractéristiques d'adhérence peuvent varier en fonction de l'état de la route et de la météo. Ainsi, on ne peut prévoir les réactions du conducteur pouvant influencer la réponse globale du véhicule dans des situations d'urgence. Le contrôleur devrait prendre en compte tous ces aspects pour préserver un comportement stable du véhicule. Bien que le contrôle latéral du véhicule présente une importance majeure dans la stabilité globale du véhicule, le présent travail est concentré sur le contrôle longitudinal du véhicule, puisqu'il représente le point de départ de la dynamique véhicule.
The main objective of the present thesis focuses on the integration of the in-wheel electric motors into the conception and control of road vehicles. The present thesis is the subject of the grant 186-654 (2010-2013) between the Laboratory of Signals and Systems (L2S-CNRS) and the French Institute of Petrol and New Energies (IFPEN). The thesis work has originally started from a vehicular electrification project, equipped with in-wheel electric motors at the rear axle, to obtain a full electric urban use and a standard extra-urban use with energy recovery at the rear axle in braking phases. The standard internal combustion engines have the disadvantage that complex estimation techniques are necessary to compute the instantaneous engine torque. At the same time, the actuators that control the braking system have some delays due to the hydraulic and mechanical circuits. These aspects represent the primary motivation for the introduction and study of the integration of the electric motor as unique propelling source for the vehicle. The advantages brought by the use of the electric motor are revealed and new techniques of control are set up to maximize its novelty. Control laws are constructed starting from the key feature of the electric motor, which is the fact that the torque transmitted at the wheel can be measured, depending on the current that passes through the motor. Another important feature of the electric motor is its response time, the independent control, as well as the fact that it can produce negative torques, in generator mode, to help decelerate the vehicle and store energy at the same time. Therefore, the novelty of the present work is that the in-wheel electric motor is considered to be the only control actuator signal in acceleration and deceleration phases, simplifying the architecture of the design of the vehicle and of the control laws. The control laws are focused on simplicity and rapidity in order to generate the torques which are transmitted at the wheels. To compute the adequate torques, estimation strategies are set up to produce reliable maximum friction estimation. Function of this maximum adherence available at the contact between the road and the tires, an adequate torque will be computed in order to achieve a stable wheel behavior in acceleration as well as in deceleration phases. The critical issue that was studied in this work was the non-linearity of the tire-road interaction characteristics and its complexity to estimate when it varies. The estimation strategy will have to detect all changes in the road-surface adherence and the computed control law should maintain the stability of the wheel even when the maximum friction changes. Perturbations and noise are also treated in order to test the robustness of the proposed estimation and control approaches.
PDF
