Rotor Of Electric Motor Research Articles

Analysis of bending and torsional modal of PMSM rotor systems for EV

Abstract The rotor system is crucial in the all-in-one integrated power system of EV, making the study of its dynamic mechanical performance at high speeds imperative. This paper focuses on analyzing the modal characteristics of EV rotor systems and the impact of individual components on bending and torsional vibrations. Using finite element analysis (FEA), a modal analysis of a 100 kW high-speed electric motor rotor is conducted, followed by experimental tests using an exciting method. Comparing simulation with experimental results reveals how end caps and bearings reduce the rotor’s bending natural frequency (BNF), while the core increases it. Additionally, the addition of rotor components leads to varied reductions in the rotor’s torsional natural frequency (TNF). Furthermore, the error between FEA and experimental values for combined rotor modes remains within 3.53%, affirming the accuracy and reliability of the analysis in predicting rotor modal characteristics.

Advancing Structural Optimization of an Electric Motor Rotor through Mesh Morphing Techniques

The electric motor has been one of the most important inventions of the last two centuries and has become increasingly important in the last 10 years thanks to its efficiency and its ability to reduce pollution. Given this increasing importance of electrical motors, an interest in design and optimization approaches for motor components is arising. Given the different physics involved in the transformation from electrical to mechanical energy, a valuable and reliable approach has to be applied in the optimization process. In past years, Mesh Morphing based on Radial Basis Functions (RBF) has largely proved its validity in generating shape modification for Finite Element Method (FEM) models. In this work, authors will demonstrate the advantages in applying two opposite approaches for shape optimization using RBF Mesh Morphing applied to electrical motors rotors. These components need to be accurately designed in order to guarantee an adequate life duration by reducing stresses in the rotating components. The two approaches that will be described are the parameter based one, in which a set of design parameters will be varied to generate shape modification used to feed a meta-model that will be used to identify an optimal configuration, and a parameter-less approach, in which the shape modification will be driven by FEM analysis results, with the aim to reduce stress hot-spots.

Non destructive control of permanent magnet rotors in a perspective of electric motor circularity

This work presents an innovative non destructive control process in order to guide for the end of life (re-use or recycling) of permanents magnets (PM) rotors of electric motors. The process is based on the measurement of the external field produced by the PM rotors. A Finite Element model of the rotor and its environment has been used to simulate a process of classification of the geometry of PM rotors, crucial information for the disassembling of the PM. Firstly, using a finite element model, we were able to investigate the field distribution outside the rotor of the magnetic flux density for different PM rotors designs. From this information, we can set up a classification methodology, based on the Central Voronoi Tessellation (CVT) method, which can help to identify how the PM are inserted within the rotor. This information can be very useful to choose PM disassembling process that should be applied.

INVESTIGATION TORSION SYSTEMS OF BLANKS ROTATION IN INFEED GRINDING ON MACHINE-TOOLS MOD.3A151 AND 3A152

In article presented investigation of static and dynamic characteristics torsion systems of blanks rotation in the machine-tools produced by Kharkov machine-tool plant. These blanks rotation systems differ in v-belt transmissions from rotor of electric motor to spindle of headstock.
 In the machine-tool 3A151 this v-belt transmission is two-steps with total transmission relation 4.4 , but in the machine-tool 3M152 is one step with transmission relation 2.5. This investigation was realized on the base of system differential equations (DE) balance discrete systems by state space equations and with the help of structure rotation systems in the view transfer functions elements of drivers and the ties between thems.
 In (DE) are take account damping energy of rotation vibrations in electromagnetic ties rotor with stator direct-current motor. From drivers models in state space was received its gain-frequency characteristics in input action on the drivers cutting moment with autput action by angular velocity of blank. The analysis of roots characteristic equations of transfer functions showed its stability but long damping with very little amplitude of vibrations, which cannot make worse of geometrical quality grinding surface. The drivers which compare are not different by
 their dynamic characteristics. But they very different by their statistic characteristics. It was established that in driver with two-step belt transmission with motor 2PD100MYXL4 impossibly get rotary velocity of blanks little diameters (30-40)mm over 50m/min which demands for reduce of maximum temperatures heating of surface in infeed grinding. For driver with one step belt transmission this limitation not take place. It was established that energy of grinding in driver with two-step belt transmission in 1.5 times more of it in driver with two-step belt transmission. Such as changing driver in machine-tool 3M152 with comparison machine-tool 3M151 was purposely.

Spectrum characteristics and temperature measurement error of FBG sensor based on rotor temperature monitoring system

For real-time temperature monitoring of a generator or electric motor rotor, the effects of rotation on the reflection spectrum of a polyimide-coated Fibre Bragg Grating (FBG) were analyzed using formulas. The measurement error resulting from the low-speed operation was evaluated, combined with the finite element method. Secondly, the key design of the FBG sensors and the mating part of the fiber optic rotary joint (FORJ) were investigated. The temperature of a rotating shaft was monitored to test the reliability of the measurement system. With a resolution of 0.1℃, the system was able to achieve an error of 0.5℃ over a range of 30-180℃. Finally, the critical conditions for the application of polyimide-coated and metal-coated FBGs were discussed. The results show that the variation of the center wavelength is more sensitive to the radius of the small-sized rotor, and the rotation speed of the large-sized rotor. It is at higher speeds that the thickness of the coating has a more pronounced effect on error, demonstrating that the accuracy of FBGs used in high-speed rotors could be rapidly improved by reducing the thickness of the metal coating. The reported results provide a basis for the thermal monitoring performance of FBG sensors during rotation.

Model of the supporting leg of an anthropomorphous robot or exoskeleton with two movable links taking into account the dynamics of the electric drive. Power engineering: research, equipment, technology

Currently, the direction associated with the development of exoskeletons and anthropomorphic robots is experiencing rapid growth due to the increase in the computing power of microprocessors and the breakthrough development of the theory of control of complex systems, including electromechanical systems that simulate the biomechanics of the human musculoskeletal system. This paper presents a controlled mechatronic robotic model of the support leg of an anthropomorphic robot or exoskeleton with two moving links.GOAL. Mathematical modeling of the dynamics of the supporting leg of an exoskeleton or an anthropomorphic mechanism in the form of two moving links.METHODS. The main difference between the model presented in this study and those created earlier is the use of angles counted between links corresponding to the case of real operation of electric drives. To achieve the goal of the work, the methods of robotics, mathematical modeling, mechatronics, theoretical mechanics, the study of systems of ordinary differential equations, control theory, empirical data for the human musculoskeletal system were applied.RESULTS. For the model of the mechanism, a system of Lagrange equations of the second kind is written, direct and inverse problems of dynamics are solved for a given program control of the motion of a mechatronic robotic system. The results are presented graphically and as an animated visualization of the movement of the links. Calculations were carried out both without taking into account the dynamics of electric drives, and taking into account the rotation of the rotors of electric motors. It has been established that the influence of the dynamics of the rotor of the electric motor on the mechanism is significant.CONCLUSION. The developed methods for setting the program movement of the supporting leg of an exoskeleton or an anthropomorphic robot made it possible to solve direct and inverse problems of dynamics and establish the need to take into account the rotating rotor of an electric motor.

Selective laser melting of a Fe-Si-Cr-B-C-based complex-shaped amorphous soft-magnetic electric motor rotor with record dimensions

A record large amorphous rotor bearing an intricate 3D-geometry is produced through additive manufacturing via selecting laser melting using a powder of a bulk metallic glass-forming composition of the Fe-Si-Cr-B-C system. Not only does this technique overcome the technical limitations characteristic of casting processes for amorphous alloys, but also the possibility to print complex 3D geometries is expected to greatly facilitate the channelling of the magnetic flux, when such component is used as a rotor in an electric machine. The rotor is characterized in comparison to the powder material as well as the as-spun ribbon using complementary techniques, including synchrotron x-ray diffraction, calorimetry, scanning and transmission electron microscopy as well as room temperature ferromagnetic and hardness testing. The rotor has extraordinarily high values of hardness (877 HV), high electrical resistivity (178.2 µΩ cm) and remarkable high magnetic susceptibility (9.17). This latter feature leads to a better magnetic response in the presence of an external magnetic field evidenced by a faster approach to saturation. The coercivity is relatively small (0.51 kA/m) and the magnetic saturation relatively high (1.29 T). In addition, a large anisotropic effect on the magnetization response in connection with partial crystallization in the melt pool areas is assessed experimentally.

Analysis of energy losses in electric transmis-sion taking into account the Sommerfeld – Kononenko effect

The use of an electric drive in modern vehicles allows solving a number of problems related to the issues of environmental and energy security of the country. However, this approach imposes a number of practical limitations. Among them there is such a significant factor as the limitation on the stored energy in the traction batteries and, as a consequence, the limitation of the mileage on one charge. One of the ways to solve this problem is to reduce mechanical losses associated with the appearance of resonance phenomena in rotating transmission elements and having an unbalanced mass. Goal. The goal is to assess the influence of the Sommerfeld – Kononenko effect on energy indicators during the transfer of rotation from the electric motor to the drive wheel of an electric vehicle.
 To achieve this goal, it is necessary to determine the law of motion of the rotor of an electric motor and a car wheel using the energy approach and a model of complex motion. Methodology. To solve the problem of determining the law of rotation of an electric motor rotor, a dynamic model of an eccentric vibrator is adopted. The study takes into account the fluctuations in the angular velocity of the shaft with Hooke's hinge when the shaft axis deviates from horizontal positions. It is proposed to apply an energy approach using a model of complex motion to determine the law of rotation of an electric motor rotor and a wheel. Results. The dependence of the speed of rotation of the wheel of an electric vehicle is determined in accordance with the dynamic model under the conditions of fluctuations in the angular speed of transmission elements with Hooke's hinge when the wheel axis deviates from the horizontal position. Practical value. An energy approach is proposed for finding losses in a complex motion model to determine the law of rotation of an electric motor rotor and a wheel.
 An analytical dependence of additional energy losses caused by wheel unbalance on vehicle mileage and wheel unbalance is found.

Stability Criterion for Stationary Solutions of Multi-Current Model Equations for a Synchronous Gimbal-Mounted Gyroscope. Part 1

We study the dynamics of a gimbal-mounted gyroscope, which has a vertical external gimbal axis and is equipped with a synchronous electric drive that rotates a gyroscope (electric motor rotor). A mathematical model of the electric motor that includes differential equations for electric currents in the rotor windings is used. Both friction and control torques on the gimbal axes are assumed to be absent. Friction torque on the rotor axis is a nonlinear function of the angular velocity of its rotation relative to the stator. The differential equations of motion for such an electromechanical system have an infinite set of stationary (steady-state) solutions that describe its stationary motions, namely, regular precessions and uniform rotations of the rotor. Due to the verticality of the outer axis of the gimbal suspension, the considered system of differential equations has a first integral, which expresses the constancy of the projection of the angular momentum of the device onto the vertical axis. In the present article we have proved that the presence of an isolated minimum of the total reduced potential energy is the necessary and sufficient condition for the stability of stationary (steady-state) motions. Thus, the previously obtained result using a simplified non-current model of a synchronous electric motor is generalized to the case of the multi-current model. Content of the study is presented in two articles. In the first part, we consider the cases when the mechanical reduced potential energy is not identical constant with respect to the internal gimbal angle. In the second part, we analyze the case of constancy for the mechanical reduced potential energy.

Analysis of Energy Management of Garnesa Electric Car Based Numerical Simulation Modeling

Designing an electric car to compete with ESCC should be guided by Vehicle Construction and Stability. One of the areas to consider when designing at the research and development stage is the Mechanical Mechanical System (Rotational Mechanical System). These systems include, wheels, transmissions (gear connections), electric motor rotors and shafts. The purpose of this study was to determine the effect of vehicle energy management on driver driving strategies during the ESCC competition. This is based on Wheel Mechanical System modeling, Dynamic System Analysis and Free Body Diagram. The method used is based on Numerical Simulation. The data parameters used are based on independent variables and control variables. The independent variable of this study is the angular velocity (V?), linear velocity (v) of the vehicle, friction coefficient value (B), shaft stiffness (K), wheel diameter, gear diameter, wheel mass and moment inertia of the wheel. Control variables is technical regulation of ESCC Urban Concept. This Numerical Simulation Test is to determine the required electrical power, travel time and distance of the vehicle. The results showed that the energy needed by GARNESA electric car with an average speed selection of 9.42 m /s based on a maximum speed of 10.15 m /s and a minimum speed of 8.70 m /s requires the amount of power 248.15 Watt. Travel time is 180 seconds in one lap. The distance obtained is 1357 m. Driving strategy based on average speed of 9.42 m /s consumes less power and the distance obtained will be more far.

Method for determining the parameters of an electromechanical transmission of an industrial tractor

In this paper, authors propose a method for determining the mechanical characteristics of traction electric motors and parameters of an electromechanical transmission of an industrial tractor. To ensure maximum machine performance, the developed transmission has two mechanical ranges: transport and technological. A feature of the presented scheme is the inclusion of a «ZK» type rotation mechanism (developed by the staff of Bauman MSTU G. Zaichik, M. Kreines and M. Kristi) in its composition. This mechanism is characterized by high traction in turning. The layout of industrial tractors involves placing the transmission in a cramped space inside the frame. In this regard, when developing the unit, it was required to implement its most compact design. This was achieved by using the same planetary gears to form the «ZK» rotation mechanism and for the reduced «technological» transmission range. As part of the study, traction capabilities of the tractor in each range were evaluated. In addition, an analysis was made of the influence of the design parameter of the planetary gears of the «ZK» mechanism on the operational characteristics of the machine. Depending on the design parameter, the required torques and rotational speeds of the traction electric motor rotors were obtained to ensure a given driving mode in a turn, and the time to complete a full rotation of the machine around the center of mass and the stopped side in the «transport» and «technological» transmission ranges was determined. In conclusion, an assessment was made of the influence of tractor transmission parameters on the maximum speed of maneuvers, which made it possible to determine the required power of electric machines taking into account the comfortable work of the driver-operator.

Fatigue life calculation procedure for the rotor of an embedded magnet traction motor taking into account thermomechanical loads

Abstract Working cycle and load fluctuation have to be considered in the design process of traction motors in order to be able to optimize the size, life cycle, and performance of the electric drive. The total stress and fatigue life of an electric motor rotor are determined to a large extent by centrifugal forces, tangential forces caused by torque, and the temperature gradient along the rotor. Rapid increase in heat as a result of sudden variation in the electric current and the differing thermomechanical characteristics of the components leads to non-uniform stress in the assembly. By applying the principle of superposition to the transient mechanical and thermal stress, a multidisciplinary method is proposed for the calculation the equivalent von Mises stress for a fatigue life analysis. This paper presents a fatigue life calculation procedure considering the mechanical and thermal stresses. The method is presented using the rotor of the Electric RaceAbout (ERA) traction motor as a case example. The presented approach is validated by comparing simulated and measured temperature data from ERA drive tests at the Nurburgring Nordschleife track. The results indicate the great importance of taking into consideration both mechanical and thermal loads in lifetime calculation.

散斑运动模糊复原的直线电机动子位置检测

散斑运动模糊复原的直线电机动子位置检测

Lightweight Design and Manufacturing of Composites for High-performance Electric Motors

The global demand for carbon saving and green mobility is changing propulsion systems from combustion engines to electric motors. Today, battery capacities are still low and the range of automotive vehicles needs to be improved. In this context, high-performance electric motors of high energy efficiency as well as low weight are gaining in importance.In the present paper, two approaches for reducing weight of electric motor rotors are presented. First, a lightweight approach comprising a hybrid shaft made of carbon reinforced plastic and stainless steel are outlined. It is manufactured by a novel process chain, where dry filament winding is combined with centrifugal casting. The steel inlays are joined in-mold during centrifugal casting. The second approach demonstrates the replacement of electric sheets by soft magnetic compounds (SMC, iron filled polyamide compound). These SMC parts are produced in an innovative two-component injection molding process. The paper concludes with a concept for the assembly of the hybrid shaft with the SMC parts and the mechanical testing of the assembled lightweight rotor.

DECREASING OF MECHANISMS DYNAMIC LOADING AT THE TRANSIENT STATE

Purpose. It is necessary to select modes of motion to reduce the dynamic loads in the mechanisms. This choice should be made on optimization basis. The purpose of research is to study methods of synthesis regimes of mechanisms and machines motion that provide optimal modes of movement for terminal and integral criteria. Methodology. For research the one-mass dynamic model of the mechanism has been used. As optimization criteria the terminal and comprehensive integral criteria were used. The stated optimization problem has been solved using dynamic programming and variational calculation. The direct variation method, which allowed finding only approximate solution of the original problem of optimal control, has been used as well. Findings. The ways of ensuring the absolute minimum of terminal criterion have been set for each method of problem solving. The stated characteristics show softness changes of kinematic functions during braking of mechanism. They point to the absolute minimum of adopted terminal criterion in the calculation. Originality. It is necessary to introduce new variables in the system equations during the solving of optimal control problems using dynamic programming to achieve an absolute minimum of terminal criteria. In general, to achieve a minimum of n-order terminal criterion an optimization problem should find relatively (n+1)-th order function. When optimization problems is solving by variational calculation in order to ensure a minimization of n-th order terminal criterion by selecting the appropriate boundary conditions, it is necessary to solve the Euler-Poisson 2(n+1)-th order equation (subject to symmetric setting boundary conditions). It is a necessary condition for an extremum of the functional with the (n+1)-th order integrant. Practical value. Minimizing of adopted terminal criterion in the calculation allows eliminate the brunt in kinematic gearing of mechanisms, which increases their operational life. In addition, the reducing of the acceleration increasing intensity of system driving mass (for example, rotor of electric motor) allows reducing undesirable energy losses in a drive.

Investigation of Permanent-Magnet Motor Drives Incorporating Damper Bars for Electrified Vehicles

Understanding the need for steady-state and transient performance improvement in an interior permanent-magnet synchronous machine (IPMSM) drive, this paper exclusively investigates the IPMSM incorporating damper bars in the rotor of electric motor for electrified vehicles (EVs). First, motivation for the employment of damper bars in IPMSM is provided and justified with a case study. Thereafter, a mathematical model of an IPMSM drive with damper bars in the rotor has been developed based on $dq$ -axis theory and validated through experiments performed on a laboratory IPMSM containing damper bars. The validated mathematical model has been then employed to arrive at satisfactory rotor bar parameters for an existing IPMSM on board a commercially available EV. Moreover, a replica of the existing onboard EV motor with and without incorporating dampers have been designed, and finite-element analysis has been performed to investigate various performance characteristics. Comparative performance analyzes of both the machines with and without damper bars under steady-state and transient conditions have been performed wherever necessary, and the results elicited have been discussed.

Design of a Movement Control Equipment for Crystal Growth by the Liquid Phase Epitaxy Technique

The design and construction of a device to perform and control the movements of the substrate during the epitaxial growth of layers by the liquid phase epitaxy technique is presented. An electromagnet is used to keep the hermeticity of the system and to reduce the power requirements of the electrical motor that drives the movements. The core of the electromagnet is coupled to the sliding ruler that contains the substrate through a molybdenum rod. The electromagnet is fixed to a carriage moved by a worm screw that is coupled to the electric motor rotor. The motor is controlled by a system based on a PIC18F4550 microcontroller that works as the host of a LM629, this IC is controls the position, speed and acceleration of devices whose position is given by incremental signals in quadrature. The LM629 generates a trapezoidal signal to perform the movement with a given speed and acceleration. The trajectories are defined in the PC by means of a Lab VIEW program, the data are sent to the PIC18F4550 microcontroller via the USB port that works as the interface between the PC and the LM629.

Application of hydromounts in synchronizing mechanical systems testing

This article considers the issues of the interaction of an excitation source—an asynchronous electric motor—in transient operation modes with external vibration fields that can be generated by foreign sources, in particular, by a vibrostand. It has been shown that in certain vibrostand operation modes, it is possible to observe the phenomenon of the electric motor rotor rotation frequency being captured by the external vibration field, resulting in a delay of the transient processes and extra consumption of the source energy. The results of experimental studies on the decrease in the vibration and noise levels with the use of asynchronous electric motors with hydromounts as dampers are presented. The economic prerequisites of hydromount application in power-consuming synchronizing mechanical systems have been substantiated.

Exact and heuristic algorithms for the circle cutting problem in the manufacturing industry of electric motors

Circular blanks are often cut from silicon steel plates to make stators and rotors of electric motors. The shearing and punching processes are often used to cut the blanks. First a guillotine shear cuts the plate into strips, and then a stamping press cuts the blanks from the strips. The unconstrained circle cutting problem discussed is the problem of cutting from a rectangular plate a number of circular blanks of given diameters and values, so as to maximize the value of blanks cut, where the shearing and punching processes are applied. Two algorithms based on dynamic programming are presented for generating cutting patterns, one is an exact algorithm and the other is a heuristic one. The computational results indicate that the exact algorithm is adequate for small and middle scale problems, the heuristic algorithm is much more time efficient, and can generate cutting patterns close to optimal.

Generating optimal T-shape cutting patterns for circular blanks

Circular blanks are often used in the manufacturing of the stators and rotors of electric motors. Some factories in China use T-shape cutting patterns to improve material usage. The author presents an algorithm to generate optimal T-shape cutting patterns for circular blanks. In the patterns more than one row of identical blanks can appear in a strip. A strip is in one of the two perpendicular directions, namely X direction or Y direction. The algorithm uses the knapsack algorithm and an implicit enumeration method to determine the optimal combination of blank rows in the strips, the strip numbers and directions in the pattern. The principles and steps of the algorithm are described in detail. The computational results indicate that the algorithm is efficient both in computation time and in material usage. Finally, the solution to an example is given.