High Efficiency Electric Motors Research Articles

Analysis of the Reasons for the Tearing of Strips of High-Strength Electrical Steels in Tandem Cold Rolling.

High-strength non-oriented electro-technical steels with a low thickness possess excellent isotropy of electromagnetic and mechanical properties which is highly required in the production of high-efficiency electric motors. The manufacturing process of this type of steel includes very important and technologically complex routes such as hot rolling, cold rolling, temper rolling, or final heat treatment. The final thickness is responsible for the decrease in eddy-current losses and is effectively achieved during cold rolling by the tandem rolling mill. Industrial production of thin sheets of high-strength silicon steels in high-speed tandem rolling mills is a rather demanding technological operation due to the increased material brittleness that is mainly caused by the intensive solid solution and deformation strengthening processes, making the dislocation motion more complex. The main objective of this work was to investigate the distribution of local mechanical strains through the thickness of high silicon steel hot bands, generated during the cold rolling. The experimental samples were analysed by means of electron back-scattered diffraction and scanning electron microscopy. From the performed analyses, the correlation between the material workability and the nucleation of cracks causing the observed steel strip failure during the tandem cold rolling was characterized. Specifically, the microstructural, textural, misorientation, and fractographic analyses clearly show that the investigated hot band was characterized by a bimodal distribution of ferrite grains and the formation of intergranular cracks took place only between the grains with recrystallized and deformed structures.

Design of Hybrid Controller for PV sourced Electric Vehicle with Hybrid Energy Storage System using Regenerative braking

Electric vehicles (EVs) enabled by high efficiency electric motors and controllers and powered by alternative energy sources provide the means for a clean, efficient, and environmentally friendly system. The power demanded by an EV is very variable. Hence HESS (Hybrid energy storage system) as an alternative source have been investigated with the objective of improving the storage of electrical energy. In these systems, two (or more) energy sources work together to create a superior device in comparison with a single source. In batteries and ultra-capacitors have complementary characteristics that make them attractive for a hybrid energy storage system. But the result of this combination is fundamentally related to how the sources are interconnect and controlled. Hybrid Electric Vehicle (HEV) is the most advance technology in automobile industries but long drive range in HEV is still a problem due to limited battery life. For increasing of battery life, two methods are widely used in HEV; one is with fuzzy logic-based battery management strategy and second is through improvement in regenerative braking system. Regenerative braking system used in HEV is to give backup power in deceleration mode which not only make HEV to drive longer but also increase the battery life cycle by charging of ultra-capacitor. The present work is for controlling the source of the motor present in the EV during different driving load conditions and storage of energy by implementing regenerative braking. In the proposed control action, motor speed plays a major role in switch the energy sources in HESS. To attain the objective, another controller has been designed with four math functions corresponding to the speed of the motor termed as Math Function Based (MFB) controller. The MFB controller works based on the motor’s speed and this controller creates the closed loop operation of the overall system with smooth operation between the energy sources. Thereafter the designed MFB controller combined with a Fuzzy Logic controller applied to the entire circuit at different load conditions. In the same way, MFB with Artificial Neural Network controller also applied to the circuit. Finally, comparative analysis has been done between two controllers. The motor has been applied with 6 different types of load and simulated. The MATLAB results of MFB with FLC and MFB with ANN has been attained and compared, discussed.

From F1 to Farming

High-performance, high-efficiency electric motors with their roots in motorsport are offering major benefits to farming vehicles.

Design of Electric Motors and Power Drive Systems According to Efficiency Standards

The focus of this article is the design of high efficiency electric motors adopted in power drive systems (PDS). The last efficiency standards are considered as constraint for the motor and drive design: they are introduced and described and their impact on the choice made during the design process are highlighted. As a particular case, the perspective of a motor manufacturer is adopted in order to understand which is the proper efficiency level of the motor required to fulfil the efficiency requirements of the PDS. This is not always clear and easy to understand because different standards apply in the two contexts. A design example of an industrial motor with 3 kW power is included, showing also experimental results on a prototypes. Also the standards related to the experimental tests, in particular those prescribing instrument accuracy, are considered and commented in the article.

Predictive Direct Torque Control of Switched Reluctance Motor for Electric Vehicles Drives

The electrical drive systems utilized in Electric Vehicles (EVs) applications must be reliable and high performance. To providing these specifications, it is essential to design high-efficiency electric motors and develop high-performance controllers. This study introduces direct torque control of Switched Reluctance Motor (SRM) for electric vehicle applications using Model Predictive Control (MPC) technique. The direct torque control using MPC is proposed to maintain the motor torque and motor speed to tracking desired signals with a satisfactory response. In this study, the MPC algorithm was programmed in C- language, and the simulation tests were performed using a non-linear model of 6/4 - 60 kW SRM that is fed with the symmetrical converter. The proposed controller was tested under different load conditions to verify the robustness of the controller, as well as at variable speeds to investigate the tracking performance. Thanks to the proposed method, the SRM torque ripples, stator copper losses, and average switching frequency of the power converter can reduce effectively due to applying a cost function that combines multiple objectives. The obtained outcomes show the effectiveness of the suggested approach compared to conventional direct torque control techniques.

Life cycle cost analysis of a computerized numerical control machine tool: a case study from Indian manufacturing industry

PurposeLife cycle cost (LCC) analysis is one of the key parameters in designing a sustainable product or system. The application of life cycle costing in the manufacturing industries is still limited due to several factors. Lack of understanding of LCC analysis methodologies is one of the key barriers. This paper presents a generalized framework for LCC analysis of repairable systems using reliability and maintainability principles.Design/methodology/approachThe developed LCC analysis framework and stochastic point processes are applied for the analysis of a typical computerized numerical control turning center (CNCTC) and governing equations for acquisition cost, operation cost, failure cost, support cost and net salvage value are developed. The LCC of the CNCTC is evaluated for the renewal process (RP) and minimal repair process (MRP) approach.FindingsThe LCC analysis of the CNCTC reveals that, the acquisition cost is only 7.59% of the LCC, whereas the operation, failure and support costs dominate and contribute nearly 93% of the LCC. The LCC per day for RP requires additional US$ 1.03 than that for MRP. The detailed LCC analysis of the CNCTC identifies the critical components of CNCTC and these components are: spindle motor, spindle motor cooling fan, spindle belt, drawbar, spindle bearing, oil seals, hydraulic hose, solenoid valve, tool holder, lubrication pump motor system, lubrication hose, coolant pump motor system, coolant hose, supply cables, drive battery.Originality/valueThe developed framework of LCC of a repairable system can be applied to any other repairable systems with the appropriate modifications. LCC analysis of CNCTC reveals that the procurement decision of a product or system should be based on LCC and not only on the acquisition cost. The optimum utilization of consumables such as cutting tools, coolant, oil and lubricant can save operation cost. Thus, use of high-efficiency electric motors and the usage of recommended consumables can prolong the life of several components of a system. Therefore, due consideration and attention to these parameters at product design stage itself will decrease failure and support cost and ultimately its LCC.

Development of Magnetic Material Testing Equipment

Abstract This paper deals with the development of equipment that can accurately determine the magnetic properties of small volume thin plate samples. The alloys to be tested are sheets of amorphous structure, such as Finemet alloy, which has excellent high frequency magnetic properties, making it a good candidate for the construction of high efficiency electric motors. This article discusses the components and operation of the equipment under development, whilst giving a brief overview of the efficiency classification of electric motors and the importance of the emerging efficiency class.

Potential of hybrid powertrains in a variable compression ratio downsized turbocharged VVA Spark Ignition engine

After the diesel emissions scandal, also known as Dieselgate, Direct Injection Spark-Ignited (DISI) internal combustion engines (ICE) appears as the most promising alternative to mitigate the harmful tailpipe emissions from passenger cars. In spite of that, the current ICE technologies are not enough to achieve the fuel consumption/CO2 emissions targets set by the new transportation legislation (4.1 Lgasoline/100 km, 95 gCO2/km for 2021). In this complex scenario, the electrification of the powertrain using high efficiency electric motors and battery package together with sophisticated DISI engines appears as potential solution to meet these requirements. The aim of this work is to study the fuel consumption and pollutant emissions in transient conditions from a passenger car equipped with a variable compression ratio (VCR) DISI engine and electrified powertrain technologies. The vehicle behavior was simulated by means of a 0D GT-Suite model fed by experimental results obtained in an engine test bench. Mild hybrid electric vehicle (MHEV) and full hybrid electric vehicle (FHEV) architectures using a VCR DISI engine were studied. Moreover, an optimization methodology is presented to select the best vehicle configuration in terms of hardware and control strategies by means of a design of experiments (DoE). The results show that VCR allows a fuel improvement of 3% with respect to the conventional DISI fixed CR along the worldwide harmonized light vehicles test cycles (WLTC). The benefits found when combining the VCR technology with hybrid powertrains are even higher. In this sense, the fuel improvements were higher as the electrification levels increased, with 8% for MHEV-VCR and around 20% for FHEV-VCR. In terms of emissions, the two clear benefits with FHEV-VCR were the reduction of particle number (PN) and unburned hydrocarbons (HC) of around 60% and 15%, respectively, as compared to the conventional DISI.

Thermal Management of High-Power Density Electric Motors for Electrification of Aviation and Beyond

Enhanced cooling, coupled with novel designs and packaging of semiconductors, has revolutionized communications, computing, lighting, and electric power conversion. It is time for a similar revolution that will unleash the potential of electrified propulsion technologies to drive improvements in fuel-to-propulsion efficiency, emission reduction, and increased power and torque densities for aviation and beyond. High efficiency and high specific power (kW/kg) electric motors are a key enabler for future electrification of aviation. To improve cooling of emerging synchronous machines, and to realize performance and cost metrics of next-generation electric motors, electromagnetic and thermomechanical co-design can be enabled by innovative design topologies, materials, and manufacturing techniques. This paper focuses on the most recent progress in thermal management of electric motors with particular focus on electric motors of significance to aviation propulsion.

Modular battery charge equalization circuit based on state of charge for electric vehicle application

Electric Vehicle (EV)/Hybrid Electric Vehicle (HEV) enabled by high-efficiency electric motor and controller, provide the means for a clean, efficient and environmental friendly transportation system. Portable rechargeable batteries are the essential basic component in EVs. In EV/HEV system a large number of cells should be connected in series to supply enough energy, while the voltage balancing problem between cells leads to poor performance. This paper attempts modular battery charge equalization based on state of charge (SOC) under MATLAB Simulink environment.

Reduction of Iron Loss on Laminated Ultrathin Electrical Steel Sheet Cores by Secondary Current Heating Method

This paper presents the newly proposed heating method names as “Secondary Current Heating Method” to reduce the iron loss on laminated electrical steel sheet cores for high efficiency electrical motors. It is well known that the magnetic properties of electrical steel sheets, which are used for electrical motor cores, are deteriorated by the residual stress during manufacturing the electrical motors, and then the iron loss of the laminated electrical steel sheet cores of the electrical motors increases inevitably. The newly proposed Secondary Current Heating Method can improve the magnetic properties on laminated electrical steel sheet cores and reduce the iron loss of them in the very short time in comparison with conventional methods. In this paper, the electromagnetic and heating characteristics of the specimens by proposed method were confirmed, and then it was applied into the laminated ultrathin electrical steel sheet cores for high speed motors to reduce iron loss.

Configurations and control of traction motors for electric vehicles: A review

In recent decades, worldwide global warming and reduction in petroleum resources have accelerated researcher’s attention to produce alternative sustainable and environmentally clean transportation systems. Electrification of vehicular technology is capable of curbing the environmental pollution problem in an efficient and effective way, due to high efficiency electric motors, development and advancement in the field of power electronic devices, digital signal processing and advanced control techniques. This article presents a comprehensive review on different configurations/ architecture of electric vehicles(EVs) and hybrid electric vehicles(HEVs), traction motors for electric propulsion system and high performance speed sensorless control of traction drive. The basic architecture key components of hybrid vehicle and different power train configurations with respect to applications and limitations are discussed. The integral part of electric propulsion system, traction motor classes for desired operational characteristics and limitations are summarized from a system perspective with the latest improvements. High performance traction motor control techniques are discussed with respect to automotive applications. Finally, speed sensorless control techniques research trends as well as an extensive review on rotor speed estimation techniques for robust and efficient sensorless traction drive control are highlighted. This article provides state of the art key global trends and tradeoff of various technologies with future trends and potential areas of research.

Reduction of Iron Loss on Laminated Electrical Steel Sheet Cores by Means of Secondary Current Heating Method

This paper presents the newly proposed heating method named “secondary current heating method” to reduce the iron loss on laminated electrical steel sheet cores for high-efficiency electrical motors. It is well known that the magnetic properties of electrical steel sheets, which are used for electrical motor cores, are deteriorated by the residual stress during manufacturing of the electrical motors, and then the iron loss of the laminated electrical steel sheet cores of the electrical motors increases inevitably. The newly proposed secondary current heating method can improve the magnetic properties on laminated electrical steel sheet cores and reduce the iron loss of them in the very short time in comparison with conventional methods. In this paper, the electromagnetic and heating characteristics of the specimens by the proposed method were confirmed, and then it was applied into the laminated cores to reduce iron loss.

Residual stress evaluation by Barkhausen signals with a magnetic field sensor for high efficiency electrical motors

The iron loss of industrial motors increases by residual stress during manufacturing processes. It is very important to make clear the distribution of the residual stress in the motor cores to reduce the iron loss in the motors. Barkhausen signals which occur on electrical steel sheets can be used for the evaluation of the residual stress because they are very sensitive to the material properties. Generally, a B-sensor is used to measure Barkhausen signals, however, we developed a new H-sensor to measure them and applied it into the stress evaluation. It is supposed that the Barkhausen signals by using a H-sensor can be much effective to the residual stress on the electrical steel sheets by referring our results regarding to the stress evaluations. We evaluated the tensile stress of the electrical steel sheets by measuring Barkhausen signals by using our developed H-sensor for high efficiency electrical motors.

Perspectives for the Brazilian Industry of Rare-Earth Magnets

The Brazilian reserves of rare earths were updated. Brazil is among the countries with the largest reserves of rare earths in the world. Rare earths present a series of applications in the high technology industry. Magnet production is one of the applications requesting largest volumes of rare earths. Another relevant application is catalysis and Petrobras needs 1000 tons/year of La2O3 for petroleum refining. CBMM mine has a pilot plant able to produce tons of separated rare earth oxides, notably didymium (a mixing of Nd and Pr oxides) used in magnet manufacture. Serra Verde mine in Goiás also produced separated rare earth oxides. The magnet production in Brazil can be important for the high efficiency electrical motors industry and also for the automotive industry.

Synchronous reluctance motor technology: industrial opportunities, challenges and future direction

In recent years, the desire for high efficiency and high torque density electric motors without permanent magnet (PM) materials for the industrial, as well as the specialist product sectors, has increased significantly and has developed into a hot research topic. This article discusses a re-emergent type of AC electrical machine, the synchronous reluctance machine. Current EU legislation aims to tackle global energy usage and reduce greenhouse gas emissions, the synchronous reluctance motor is discussed in this article – Its potential to become the future industry standard for high efficiency, low cost, high output industrial drives for fan, pump and mill type industrial applications is explored. The author will be brought up to speed with synchronous reluctance technology, presented with both its advantages and disadvantages with the suitability of the technology for industry application being discussed and a comparison made with respect to competing technologies – the traditional induction machine and the modern PM machine. Current and future research trends are outlined and a simple engineering case study is also presented as an indication of the energy saving potential of this type of machine. This article aims to inform students, engineers and key-decision makers in industry about this exciting technology.

Semianalytical Framework for Synchronous Reluctance Motor Analysis Including Finite Soft-Magnetic Material Permeability

Due to the increasing demand for high-efficiency electric motors and the maturity of vector-controlled motor drives, the Synchronous Reluctance Motor (SynRM) has received an increasing amount of attention over the past few years. Classically, SynRMs are analysed using analytical models such as presented by Vagati et al.[1]. These models require little computation time and provide the designer with significant insight into the behavior of the machine, which can be very helpful in making initial design choices. For accurate analysis of the motor performance, however, numerical methods such as Finite Element Analysis are often used, although this significantly increases the computation time per design iteration. To limit the number of FEA simulations, a systematic design procedure for SynRMs, based on a combination of analytical models and FEA simulations, was proposed by Moghaddam et al.[2].

High Efficiency Electric Motors: Economic and Energy Advantages

The energy crisis that is currently being faced by humanity has demanded the revision of the regulations applied to different energy consumers, including electrical machines. The minimum efficiency standards for electrical machines provided by the regulations have been increased. Different categories have been defined to identify the engine based on the level of losses. Regardless of the benefits of ecological nature imposed by recent regulations, the use of the new generations of high efficiency induction engines is attractive from an economic standpoint. The lower power consumption engines and its increasing life span can allow quickly recovering the additional cost of new units and achieving further gains. In this paper the current regulations in different countries of the world are reviewed. According to the energy cost in Argentina, a computation of the times of economic payback is also presented.

Energy conservation using high-efficiency electric motors

Energy conservation using high-efficiency electric motors

ChemInform Abstract: Rare-Earth Permanent Magnets. New Magnet Materials and Applications

The introduction of rare-earth permanent magnets based on samarium-cobalt in about 1970, and neodymium-iron-boron magnets in the mid-nineteen eighties, has ushered in a new era in hard magnetic materials. This has resulted in a dramatic improvement in permanent magnet performance, with neodymium-iron-boron (Nd2Fe14B) magnets having a magnetic energy product up to an order of magnitude greater than those of Alnico and ferrite magnets, with high remanence and coercive force. The search for new permanent magnet materials has led to further interest in rare-earth-iron intermetallic compounds modified by the introduction of interstitial atoms such as nitrogen or carbon. We discuss `What makes a good permanent magnet’, in the context of the crystal structure and the magnetic properties of rare-earth-iron intermetallic alloys that are candidates for new permanent magnet materials. The methods for producing these new candidate magnet materials, including arcmelting under an atmosphere of argon, high-energy ball-milling (HEBM), mechanical alloying, melt-spinning and HDDR (hydrogenation, disproportionation, desorption, recombination) are reviewed. Examples of high efficiency electric motors, which use rare-earth permanent magnets, developed by the School of Electrical Engineering, University of Technology, Sydney, and the CSIRO Division of Telecommunications and Industrial Physics are given.