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With Increasing environmental concerns and high fuel prices, the automotive industry is shifting its focus to electric vehicles (EVs). Electric motor being the heart of an electric vehicle, faces a major design challenge to have optimum performance and structural strength at an affordable cost. Synchronous reluctance motor offers higher power density at low cost since the rotor is free from rare earth permanent magnets or field excitation. However, torque fluctuations and resulting vibrations are a major concern. This is amended by optimizing the end-barrier width and end-barrier orientation angle in the rotor so as to maximize the torque and minimize the ripple. Simulations are also performed with ferrite magnets assistance to achieve an enhanced torque output. In each case, a structural analysis is done to verify the mechanical strength and rotor deformation considering structural and electromagnetic forces. The analyses are performed using finite element simulations.

RENAULT aims to become the first full-line manufacturer putting to market zero-emission affordable electrical vehicles and is therefore developing 100 % electric powertrains. NVH problems related to electric machine design have nothing in common with those of gasoline or diesel engines: electric whistling is a high frequency harmonic phenomenon, easily detectable due to the low background noise of a non-thermal vehicle and mainly perceived as very unpleasant by the customer. Therefore we have developed a coupled numerical simulation between electromagnetic and structural models, making it possible to understand the influence of magnetic parts design on noise and vibration level. Impact of the spatial and time coherence between magnetic pressures and vibration modes of the motor will be explained. The novelty of our approach is to already take into account the whole powertrain structure radiation, including reducer and power supply boxes.

With increasing fuel demands and environmental issues, electric vehicles are more important in reaching a bearable solution. The driving motor is a vital component of electric vehicles defining the design of electric propulsion, and it has small volume, high efficiency with sufficient power for torque and speed with precise control. To ensure a satisfactory life span of the motor, temperature rise must be controlled within safe operating zone. The sizing parameters, design with magnetism, thermal and mechanical calculations are carried out for a 1016-Watt traction motor system. Effects of variation of torque and speed for the 1016-W Brushless Direct Current (BLDC) motor was performed. Power losses calculated included Winding, Stator & Rotor core losses of around 220Watt from the input power of 1236Watt. BLDC motor with air gap between cores and multi-rotational frames are selected for the above calculations.

Hybrid electric vehicles require careful dealing with EMC because in HEV's analog and digital circuitry coexist in the vehicle's enclosed environment. These lead to a requirement of advanced methods for the increased requirements for electromagnetic compatibility and analysis and reduction of EMI [1]. There are many methods to increase EMI resistance of a hybrid car's electronics systems implemented printed circuit board, several of which will be reviewed in the current paper. In this review paper, we explain conducted and radiated emission avoidance methods using isolation amongst several subsystems. Within the harsh EM environment of a modern hybrid car, isolation between systems of differing frequencies is an effective method for reducing EMI/EMC issues. These techniques include usage of filters to hinder conducted emissions and shielding to stop radiated emissions.

With the advent of electronic controls and development of electromagnetically controlled fuel injection pumps, the cost of fuel systems using plunger-type pumps was substantially reduced. Further reduction in cost can be achieved if fewer solenoid valves are used. A new type of injection pump combining electromagnetic spill control principle with distributor-type operation is described. Only one solenoid valve is required for a multi-cylinder engine. The pump was designed for port injection of gasoline, but with some modifications could be adapted to direct fuel injection. The fuel injection system includes a controller capable of electronic trimming of port-to-port fuel distribution for tight control of air to fuel ratios in all engine cylinders. A review of the basic concept and operating principles is given, and test results as well as cost considerations are discussed.

Electric motors and generators produce vibrations and noise associated with many physical mechanisms. In this study, we look at the vibrations and noise produced by the transient electromagnetic forces on the stator of a permanent magnet motor. In the first stage, electromagnetic simulation is carried out to calculate the forces per tooth segment of the stator. The harmonic orders of the electromagnetic forces are then calculated using Fourier analysis, and forces are mapped to the mechanical harmonic analysis of the second stage. As a third stage, the vibrations of the structure are used to drive the boundary of acoustic domain to predict the noise. Finally, optimization studies are made over the complete system to improve the motor design and reduce noise. A simulation environment (ANSYS Workbench) is used to integrate a seamless workflow.

A new type ECCVT system is studied. It consists of a rotor and a stator with iron winding, an additive magnetic field adjusting winding, a cup-type rotor with special magnetic pole, inductive slip rings and power electronic controller. Its specialty is that the traditional electric transmission and electromagnetism coincidence are combined and the electricity is transferred unosculantly, so that the power split is realized. The new system also puts up a compact topology, good control and stability by the way of frequency conversion and magnetic field adjusting. The system not only has a wide continuously variable range as the traditional Electric Motor, but also has a high efficiency. Being used on a car, the clutch and starter are omitted. It also can be used as the driving line of the HEV.

These days, the use of virtual Multiphysics simulations through finite element analysis methodology is increasing exponentially during the development phase of automotive products. Thereupon, the automotive industries are becoming competent enough to build an ingenious and creative design with optimal performance within the coherent time. A huge number of electromagnetic as well as mechanical forces are being generated inside the Motor, when it is undergoing extreme driving conditions of the application. Hence it becomes vital to reduce the risks, if any, during the development phase by providing an optimal factor of safety within the electromechanical system of the motor. The present study gives details about conducted finite element analysis on an automotive traction motor to determine its mechanical strength and behavior. This study also focuses on finding the structurally critical regions over the motor assembly through electromechanical (Multiphysics) simulations.

The University of Texas Center for Electromechanics (UT-CEM) has been developing active suspension technology for off-road and on-road vehicles since 1993. The UT-CEM approach employs fully controlled electromechanical (EM) actuators to control vehicle dynamics and passive springs to efficiently support vehicle static weight. The program has completed three phases (full scale proof-of-principle demonstration on a quarter-car test rig; algorithm development on a four-corner test rig; and advanced EM linear actuator development) and is engaged in a full vehicle demonstration phase. Two full vehicle demonstrations are in progress: an off-road demonstration on a high mobility multiwheeled vehicle (HMMWV) and an on-road demonstration on a transit bus. HMMWV test results are indicating significant reductions in vehicle sprung mass accelerations with simultaneous increases in cross-country speed when compared to conventional passive suspension systems.

The actual development and test of electromechanical actuation hardware for critical, manned aircraft, flight control application that is specifically designed to interface with fly-by-wire commands is now represented by only two hardware units. One of these units was built by Delco Electronics for NASA-Houston and the second unit built by AiResearch Manufacturing Company for the Air Force Flight Dynamics Laboratory. Each of these units feature inside-out motor designs using rare earth samarium cobalt permanent magnet rotors with electronic commutation and are powered with 270 volt DC electrical power. The innovative design features, incorporated in these two actuation units, are thought to have a significance for the future that will eventually influence actuation design for business aircraft.

For aircraft electromechanical actuator (EMA) cooling applications using forced air produced by axial fans, the main objective in fan design is to generate high static pressure head, high volumetric flow rate, and high efficiency over a wide operating range of rotational speed (1x∼3x) and ambient pressure (0.2∼1 atm). In this paper, a fan design based on a fan diameter of 86 mm, fan depth (thickness) of 25.4 mm, and hub diameter of 48 mm is presented. The blade setting angle and the chord lengths at the leading and trailing edges are varied in their suitable ranges to determine the optimal blade profiles. The fan static pressure head, volumetric flow rate, and flow velocity are calculated at various ambient pressures and rotational speeds. The optimal blade design in terms of maximum total-to-total pressure ratio and efficiency at the design point is obtained via CFD simulation. A 5-blade configuration yields the best performance in terms of efficiency and total pressure ratio.

The aircraft electromechanical actuator (EMA) cooling fan is a critical component because an EMA failure caused by overheating could lead to a catastrophic failure in aircraft. Fault tree analysis (FTA) is used to access the failure probability of EMA fans with the goal of improving their mean time to failure (MTTF) from ∼O(5×104) to ∼ O(2.5×109) hours without incurring heavy weight penalty and high cost. The dual-winding and dual-bearing approaches are analyzed and a contra rotating dual-fan design is proposed. Fan motors are assumed to be brushless direct current (BLDC) motors. To have a full understanding of fan reliability, all possible failure mechanisms and failure modes are taken into account. After summarizing the possible failure causes and failure modes of BLDC fans by focusing on each failure mechanism, the life expectancy of fan ball bearings based on a major failure mechanism of lubricant deterioration is calculated and compared to that provided in the literature.

Continental Automotive Systems started development of an electromechanical brake-by-wire system (EMB) 2 years ago. A major part of the development deals with the control of the brake actuator. For the development of control algorithms a special test stand was built. It consists of the seat capsule, the actuator and the PC-based electronic control unit. As the electronic unit also performs a real time vehicle and actuator simulation a complete Hardware-in- the-Loop system supports simultaneous engineering within this project. This paper describes the Hardware-in-the-Loop development system and shows first results obtained in an early state of the development process.

With the aim of producing innovative clutch actuation mechanisms for automotive transmissions, we are investigating a design based on power screws. The design strives to improve clutch actuation technology and minimize energy consumption by maintaining clutch lock-up independent of an external energy source. The system consists of a lead screw shaft-and-nut assembly, a clutch apply-plate, a set of wet clutch disks and a brushless DC motor. The clutch actuation assembly is separated from the clutch-pack via thrust bearings, which allows the use of a motor, while reducing the inertial load imposed by the conventional clutch-pack. A prototype of the design was fabricated and installed on a testbed, to mimic the installation of the actuator to replace the hydraulic components. A standard 12-disk clutch-pack of an automatic transmission was used within the apparatus. The formulation of the mathematical model of the entire testbed is described in this paper.

This paper describes the feasibility of a de-icing device based on forced vibrations induced in an ice-covered rectangular aluminum plate using an amplified piezoelectric actuator. The removal of the ice layer is caused by the creation of mechanical stresses induced by relatively fast time-varying mode shapes in the very low kHz-range large enough to overcome the adhesion forces at the material/ice interface.

This paper presents a multi-physic modeling of an electromechanical energy scavenging device able to supply energy inside car tires for wireless sensors. A permanent magnet, connected to the inner liner of a tire, is accelerated along a guide by the tire deformation during car motion; by interacting with coils it generates a power which is conditioned by a proper electronic interfaced to an external load. The original approach implemented in this kind of device is the nonlinear dynamic properties designed and controlled: adaptive resonance in function of car velocity is optimized for increasing its global efficiency. The energy conversion process takes into account the simulation of different phenomena such as: non linear dynamic and adaptive resonant behavior of the seismic mass, electromagnetic and magneto-static coupling between moving mass and coils, transfer of the generated power to an external load by means of a nonlinear circuit interface.

The new rare-earth sammarium-cobalt magnets are revolutionizing electromechanical actuation design to the extent that power-by-wire can be a legitimate follow-on to fly-by-wire. These new magnets coupled with innovative design techniques which feature direct interface with fly-by-wire are creating electromechanical actuator designs that are highly competitive to hydraulic actuators in terms of weight, space, and performance. A major promise of these new electromechanical actuators is to permit unification of total secondary power systems under a single medium, electrical.

The new rare-earth sammarium-cobalt magnets are revolutionizing electromechanical actuation design to the extent that power-by-wire can be a legitimate follow-on to fly-by-wire. These new magnets coupled with innovative design techniques which feature direct interface with fly-by-wire are creating electromechanical actuator designs that are highly competitive to hydraulic actuators in terms of weight, space, and performance. A major promise of these new electromechanical actuators is to permit unification of total secondary power systems under a single medium, electrical.

Four independent guidance fin actuation subsystems have been packaged in an air vehicle section only four inches in diameter. The Control Actuation Section (CAS) of the IRTGSM submunition is seven and one half inches long. Within this envelope are the four electromechanical actuators, three thermal batteries, Flight Control Element Electronic (FCEE) module, four guidance fins (in the retracted position), and connector and structural interfaces. Location of the CAS and the air vehicle are shown in Figure 1.

Many researches focus on piezoelectric ice protection systems with the objectives to develop light and low consumption resonant electromechanical systems for de-icing. These systems use the vibrations generated by piezoelectric actuators at resonance frequencies to produce shear stress at the interface between the ice and the support or to produce tensile stress in the ice. This article presents experimental results of de-icing tests performed with resonant piezoelectric systems that generate amplitudes of vibrations to exceed ice tensile strength or ice/support adhesive shear strength. The tests show that fractures are initiated but that the ice is not always completely detached. A methodology based on the energy release rate is presented to enable a better understanding of fractures initiation and propagation.