Motor Manufacturers Research Articles

Winding Factors and Magnetic Fields in Permanent-Magnet Brushless Machines With Concentrated Windings and Modular Stator Cores

Removing some sections of the stator yoke in a permanent-magnet brushless machine can be beneficial for reducing punching waste and simplifying motor manufacture. However, in some cases, restricting the possible flux paths, in this way, will have a detrimental impact on the torque and air-gap harmonics. This paper discusses the potential implications of modular stator core arrangements and presents the air-gap flux density harmonics and winding factors for potential slot/pole combinations. Finite-element analysis (FEA) simulations are presented to support the analytical calculations. The analysis indicates that the performance reduction from using a modular stator is minimal when the number of slots and poles are similar but drops off substantially when this is not the case. A modular core stator will increase the MMF subharmonics due to the magnet field but can reduce the subharmonics due to the armature if a single-layer winding is used. The effect of slotting is very similar for a modular and conventional core machine, and FEA results match previously published analytical analyses.

COMPARATIVE ANALYSIS OF WEIGHT AND COST INDICATIONS OF INDUCTION MOTORS WITH CYLINDRICAL AND AXIAL AIR GAPS

Purpose. To find the analytical expressions of determining the optimum geometric dimensions by criteria of the weight minimum and the cost minimum of axial field squirrel-cage induction motors and to compare traditional and axial field motors. Methodology. We have applied the adapted method of the relative indications of the technical level with relative controlled variables. We have used the approximation of the experimental dependence of the distribution of the induction in the air gap and the integral averaging of the electromagnetic characteristics. Results. We have developed the mathematical model for determining the optimum geometric dimensions by criteria of the weight minimum and the cost minimum of the active part of axial field squirrel-cage induction motors taking into account the radial distribution of the induction in the air gap and teeth. We have considered the comparative analysis of the indications of the weight and the cost of traditional and axial designs of electromagnetic equivalent motors. Originality. For the first time we have created the relative units mathematical model of the weight and the cost of the active part of axial field squirrel-cage induction motors with the uneven distribution of the magnetic flux in the core and investigated the effect of the geometric relationships on the materials consumption and cost of axial field motors. Practical value. Based on the superior parametric compatibility and the high material savings of axial motors the expediency of replacing traditional induction motors to axial field induction motors has been proved in the special transport drives. Also obtained by simulation optimal geometric relationships of the magnetic circuit can be used in the manufacture and design of axial motors by criteria of the weight minimum and the cost minimum.

Technical and economic considerations on induction motor oversizing

In industry, due to conservative system design, safety factors associated with uncertainty in the load requirements, discrete availability of commercial rated power, and/or load power variation, most three-phase squirrel-cage induction motors are oversized. Besides the extra capital investment, the oversizing of direct-on-line fixed-speed induction motors can lead to a significant efficiency and power factor reduction. However, the part-load efficiency of oversized motors can still be higher than the full-load efficiency of well-sized smaller motors because, in general, the nominal efficiency increases with the rated power. In this paper, an analysis of potential benefits and drawbacks of motor oversizing is carried out. On the basis of the catalogue technical data provided by one of the largest motor manufacturers for IE1-, IE2-, IE3-, and IE4-class four-pole induction motors, the main results of a simulation-based study on the oversizing energy efficiency and cost-effectiveness are presented. A method to estimate the motor efficiency and power factor for any load level using commercial catalogue data is proposed and applied. Some technical issues associated with motor oversizing are also briefly addressed. It is shown that, if the additional reactive energy consumption due to poorer power factor and the slight speed increase are ignored, for IE1-, IE2- and, to a much less extent, IE3-class motors, oversizing can be cost effective for many motor rated powers, resulting in a higher average efficiency and a lower motor lifecycle cost, as well as in an extended motor lifespan. For most IE3- and IE4-class motors, the oversizing is not cost effective because of the lower nominal efficiency gain when moving to a higher oversized rated power. Additionally, the oversizing impact on the motor energy consumption strongly depends on the load profile of the application. When an old motor fails, it will probably be an IE0- or IE1-class equivalent motor, and this situation provides a golden opportunity for replacing the old motor with a properly sized IE3- or IE4-class motor, which offers significantly higher efficiency for a wide range of loads.

A Novel Surrogate-Assisted Multi-Objective Optimization Algorithm for an Electromagnetic Machine Design

To design electric machines, the motor performance, cost, and manufacturing have to be considered. Hence, researchers have called this the multi-objective optimization (MOO) problem in which the goal is to minimize or maximize several objective functions at the same time. In order to solve the MOO problem, various algorithms, such as nondominated sorting genetic algorithm II and multi-objective particle swarm optimization, have been widely used. When these algorithms are applied to the electric machine design, much time consumption is inevitable due to many times of function evaluations using a finite-element method. To solve this problem, a novel surrogate-assisted MOO algorithm is proposed. Its validity is confirmed by comparing the optimization results of test functions with conventional optimization methods. To verify the feasibility of its application to a practical electric machine, an interior permanent magnet synchronous motor is designed.

The Passenger Car in Portugal: Features of Functional Modules

This article focuses on the study of the analysis model on the functional modules of the passenger car in Portugal, made in the course of the PhD in Design. In an analysis with reference to the global segmentation of passenger car, appealed to the formation of a summary table showing the classification of segments of the key players in the sector, in particular brands of car manufacturers, the International Organization of Automobile Manufacturers, the Society of Motor Manufacturers and Traders, the Japan Automobile Manufacturers Association, the Society of Indian Automobile Manufacturers, the Association of European Automobile Manufacturers and the Automobile Association of Portugal. Therefore, we compared the different rating scales, number of categories and technical specifications that serve to differentiate the segments together. In addition to this information, also considered the conclusions reached up to the questionnaire to the target audience. Finally, to complete the set of samples, were consulted the three sites of the best-selling brands in Portugal during the year 2013 (Renault, Peugeot and Volkswagen) and two sites of major international companies rent-a-car to operating in Portugal (Europcar and Avis). With these three fields samples proceeded to completion of the final motion diagram that identifies the functional modules of each of the segments of the passenger car, including the engine, the interior front and rear passengers, the zone for the transport of luggage, pets or goods and finally the variations of the main module for each typologies.

Managing the change of strategy from customisation to product platform: case of Mabuchi Motors, a leading DC motor manufacturer

This paper analyses how component manufacturers can change from a customisation to a product platform strategy. This change requires component manufacturers to deal with issues related to the product architecture of the component itself and to the product development process required to sustain the platform strategy. This paper presents an in–depth analysis of the change in product strategy of Mabuchi Motors, a specialised DC motor manufacturer that sells DC motors for an average of 50 yen and that has enjoyed long–term stability and high profitability. The process involved in changing product strategy is analysed from two perspectives, the design concept (product architecture) of the DC motor, and its product development process. Academically, this study may contribute to enhancing the quality of product platform strategies by expanding these strategies from end product manufacturers to component manufacturers.

Electromagnetic Field Analysis of Pumped-Storage Generator-Motor Using Three Dimensional Finite Element Method

Pumped-storage power plants are extensively used in power systems because of excellent performances in peak load, frequency regulation and emergency reserve. Generator-motor is an important part of pumped-storage power plant and plays a key role in the operation of the whole power plant, consequently the safety and stability of the power plant and even the power grid are directly influenced by the performance of generator-motor. This paper offers a 3-D eddy current field calculation on generator-motor of Guangzhou Pumped-storage Power Plant B using finite element method (FEM). A 3-D generator-motor model is presented in this paper and the distribution of current density and flux density are educed, as well as the radial air-gap flux density and the harmonic analysis. Through the calculation on 3-D eddy field of generator- motor, electromagnetic distribution, mechanical strength, magnetic flux density and winding current of motor are obtained, offering reference for the design, model selection and localized manufacturing of motor. Keywords: 3-D calculation, electromagnetic field analysis, finite element method, generator-motor, pumped-storage.

Multi Parameter Sliding Test Result Evaluation for the Selection of Material Pair for Wear Resistant Components of a Hydraulic Motor Dedicated for Use with Environmentally Friendly Working Fluids

In the paper the method and results are presented of the testing of tribological performance of a number of hard materials available commercially. The tests consisted in unidirectional sliding with liquid lubrication. The load and velocity regime chosen were similar to a standard four-ball lubricity test with constant velocity and load increasing over time. The regime was modified in such a way that over the initial part of the test both the velocity and load were linearly increased until a certain stable level of each input parameter was reached and the test was then continued till the termination due to chosen criteria. The materials used were high alloy tool steels and sintered carbides, normally used in working of metals by cutting. The lubricants environmentally inert or friendly fluids: water, mineral oil-in-water emulsion and vegetable oil. In the tests, typical sliding friction parameters were recorded, later evaluated on the basis of multiple parameters observable within the test such as e.g. maximum load and velocity reached, calculated maximum surface pressure or presence and amplitude of friction induced vibrations. In the group of material/material/lubricant combinations a ranking was created for each parameter in the assessment set by awarding points for performance. Best performance was granted the least amount of points. Overall performance was then judged by the accumulated number of points. The materials, which were evaluated as performing best have been chosen as input materials for the design and manufacture of a prototype motor for later laboratory and field testing.

Business Focus: Analysts are not betting many chips on US behemoth

UK CAR production is booming, bringing the sector ever closer to its all-time high in the 1970s, with some auto manufacturers in Britain planning further investment and growth. In April 2014 car output in the UK stood at 133,437, more than a fifth higher than in April last year, with the growth being partly fuelled by the introduction of new models, according to the Society of Motor Manufacturers and Traders (SMMT).

Characteristics Measurement of Electric Motors by Contactless Eddy-Current Magnetic Coupler

Torque-speed characteristics measurements are essential in the design and manufacture of electric motors. Dynamometers have been widely used in motor characteristics measurements, and the coupling between the motor under test and dynamometer is a critical issue for high-power electric motors. This paper develops a contactless measurement system, which consists of a permanent magnet (PM) coupler and requires no dynamometer. The torque of the PM coupler is transmitted by the eddy-current and controlled by the air gap inside the coupler. An equivalent circuit model of the magnetic coupler is derived theoretically and then verified experimentally under different operating conditions. The capacity of the proposed measurement system can also be determined in order to provide sufficient and accurate measurement information for the tested motors. A 1.5 kW dc motor with a maximum torque of 8.15 N-m was tested as an illustrated example. The experimental results are given to show the effectiveness of the proposed approach.

Viewpoint: Transport's digital age transition

2014 marks the 25th birthday of the World Wide Web. We have seen some remarkable developments as part of the digital age revolution in the last quarter of a century. These have taken place concurrently with a motor age that is possibly past its prime. A number of major motor manufacturers have faced disappointing sales or financial crisis alongside several countries seeing a halt to the historic trend of growing car use. The co-existence of the motor age and the digital age prompts this paper to consider the hypothesis that society is undergoing a fundamental transition from a regime of automobility to something significantly different. The paper considers what has characterized the motor age and proceeds to examine the digital revolution and how this is changing people’s means to access people, goods, services and opportunities. The range of interactions between the motor age and the digital age are addressed, underlining the difficulty in establishing the net consequence of one for the other. The new debates concerning ‘peak car’ are considered in which the digital age is identified as potentially one key factor responsible for observed changes in car use. The paper then focuses upon a socio-technical conceptualization of society known as the Multi-Layer Perspective to examine its hypothesis. Support or not for the hypothesis is not, as yet, established. Transport’s future in the digital age is uncertain and the paper sets out some views on resulting policy considerations and research needs.

NC Wedge-Caulking Special Machine Tool Design

With mechanical processing requirements' development direction translates to highprecision, high efficiency, high quality, intelligence and specialty etc. Wedge-caulking's processinghas a lot of problems in our country energy industry market , the problems mainly show lowefficiency, poor accuracy, product quality and technical indicators are difficult to guarantee. Thispaper developed a high precision, high efficiency, intelligence, high quality and specialty machinetool, the enterprise practice results show that the NC wedge-caulking special machine tool provide thetechnical support and equipment protection for our country motor manufacturing. It has the very goodpractical value.

Comparison of Different Tapped Windings for Flux Adjustment in Induction Motors

In single-speed three-phase squirrel-cage induction motors with rated power above 3 kW, although the use of electronic soft-starters is increasing fast, the conventional star-delta starters are still the most used, requiring three contactors. In this paper, motor soft starting and/or magnetizing flux adjustment solutions based on two-flux-level, delta- and star-connected, tapped windings are proposed, providing an alternative to the conventional star/delta windings. The motor flux adjustment in the proposed tapped winding is based on the change of the winding factor and/or per-phase number of turns. The connection-mode change system for the proposed tapped windings requires only two contactors, and no extra cost is expected for the motor manufacturing or rewinding. For the proposed tapped winding arrangements, a theoretical analysis is made, and simulated and experimental results are presented. The presented solutions can be used to improve the part-load efficiency and power factor of fixed-speed variable-load motors, particularly if they operate long periods with load lower than 35%–45% and short periods with load close to 100%, and an automatic load-based winding connection-mode management system is used.

Imported from America: Cooperative Labor Relations at New United Motor Manufacturing, Inc.

Imported from America: Cooperative Labor Relations at New United Motor Manufacturing, Inc.

The Rare Earth Magnet Industry and Rare Earth Price in China

In the past four years, the price of rare earth metal fluctuates sharply for many reasons. Currently, it has become more stable and more reasonable. This presentation is focused on the effect about the rare earth metal price. Some motor manufacturers have shifted from rare earth permanent magnet to ferrite magnet. Many motor manufacturers changed the design for the motor cooling system to make the motor function at a lower temperature. Thus the consumption of Dy can be markedly reduced. As for manufacturer of NdFeB magnet, we are also trying to optimize our process to reduce to dependence of HREE such as Dy and Tb. HS process have been introduced to solve the problem. With more and more people focusing and engaging on the REE industry, the price of REE will be more transparent without too many fluctuations. China is considering the problems of balancing the environment, energy sources, and labor sources. The application field about NdFeB such as wind turbine generator, HEV/EV, FA /OA is flourishing.

An audit of employee commitment to enable leaders to manage organisational talent

Leaders in motor manufacturing companies are faced with the challenge of talent attraction, development and retention due to constant changes in manufacturing technology. Yet, these leaders are expected to recruit, train and retain specialist skills due to the highly specialised nature of their manufacturing business processes. Another threat faced by these leaders is the loss of skilled talent to their competitors. These challenges have, therefore, created the need to audit employee commitment in a manufacturing organisation in order to enable leaders to initiate talent management practices. It is against this background that this paper poses the question: What is the nature of organisational commitment of manufacturing employees for leaders to be able to manage talent? This question was addressed through a quantitative study of organisational commitment dimensions. The main objective of this study was to audit the organisational commitment dimensions (as measured by Meyer and Allen’s Organizational Commitment Scale) within a manufacturing organisation. The data was collected using a survey on a random sample size of N=371, all of whom were employees of a South African motor manufacturing organisation. The results of this study indicate that there are significant differences between organisational commitment dimensions namely; affective, normative and continuance commitments. These findings provide valuable information to assist leaders to propose talent management interventions vital for organisational talent attraction, development and retention

Design and Manufacture of a Unilateral Permanent Magnet Linear Motor for Assembly

Based on the analysis of structure characteristics of unilateral permanent magnet linear motors, two key points of assembling, how to avoid the stronger magnetic attraction and ensure dimensional precision of the air gap between primary section and secondary section, were discussed. Several new methods of designmachining and assembly process were presented, assured the accuracy and stability of unilateral permanent magnet linear motors. The measuring results met the performance requirements.

Performance Evaluation and Comparison of Switched Reluctance Cylindrical Linear Motor

Nowadays, most of the researchers have put a lot of effort in designing the permanent magnet type of linear motor. However, due to resource problem occur recently to the permanent magnet material has led to increment of the material cost. This situation made the linear motor development cost is increase as well. Because of this reason, most of linear motor manufacturers are prefer to development non-permanent magnet type to ensure stability and competitive price. Therefore, in this research, a switched reluctance linear motor was designed. The teeth shape has been varied in order to observed the effect to it’s performance. As a result, the best model of switched reluctance linear motor with optimum teeth shape has been proposed. The performance of the model also has been compared to other similar type of linear motor and the permanent magnet type of linear motor.

Effect of metallurgical factors on the bulk magnetic properties of non-oriented electrical steels

Non-oriented electrical steel (NOES) is one of the most common material used in electrical motors. Core loss and permeability are the most important properties that the motor manufacturers look for. Both these properties are structure sensitive and depend on several metallurgical factors; such as chemistry, grain size, crystallographic texture, cleanliness and stress states in non-oriented electrical steels. It has been observed in this course of the study that the grain size and Si content of NOES are the primary controlling factors to core loss, especially at higher frequencies. On the contrary, crystallographic texture plays an important role at lower frequencies. At higher frequency, core loss increases with increasing grain size and decreasing Si content of the steels. Small difference in grain size (~50μm) at lower frequency range has little influence on the magnetic properties but has significant adverse effect as frequency reaches high enough.

The Incremental Design Efficiency Improvement of Commercially Manufactured Induction Motors

The improvement of induction motor efficiency over the years has been incremental in nature. One of the well-known methods used to increase the efficiency of induction motors, cost-effectively, is by increasing the stack length. There are many motor manufacturers with proprietary designs that are optimized for different parameters, e.g., cost, volume, weight, copper, iron, etc. Therefore, the effectiveness of incrementally improving the efficiency for motors of various designs and from different manufacturers presents an interesting research. This paper seeks to determine the incremental improvement of design efficiency of motors that are already subjected to commercial production. Motors from five manufacturers were tested, torn down, and analyzed, and their design efficiency improvement is investigated.