High-efficiency Motors Research Articles

Test Results of an SRM Made From a Layered Block of Heat-Treated Amorphous Alloys

In order to produce high-efficiency motors at relatively low production costs, a layered block is made from amorphous iron sheets. From the block, stator and rotor cores of a test switched reluctance motor (SRM) are fabricated. The experimental results of the test machine are compared to another test machine made from low iron loss silicon steel type 35A300 in JIS standard. This silicon steel is equivalent to M-22, 300, and V300-35A in ANSI, BS601, and DIN46400, respectively. The validity of the test results is compared and verified through use of an analytical simulation software package. Approximately 6% improvement in efficiency is observed for the prototype SRM with the layered amorphous core material. The SRM test motor has an efficiency of 95.1% at a speed of 8500 r/min with an output of 2.4 kW.

ENERGY-SAVING HYBRID HYDRAULIC SYSTEM COMPRISING HIGHLY EFFICIENT IPM MOTOR AND INVERTER, FOR INJECTION MOLDING AND MANUFACTURING MACHINE

We have developed a novel energy-saving hydraulic pump system Super Unit that comprises a high-efficiency motor, low-inertia pump and an inverter controller (We call this type of system ‘hybrid’). Compared with conventional hydraulic pumps each driven by a constant speed induction motor, our novel hydraulic pump system driven by a high-efficiency variable-speed IPMSM (Interior Permanent Magnet Synchronous Motor) features energy-saving of 40% or more when used for an injection molding machine which is a typical application of this new pump system.By means of a pressure feedback control function and run speed control software on the controller, the pressure and fl ow rate of the hydraulic fluid are accurately controlled according to a command from the controller of the molding machine. This control software allows a high-torque high-precision motor to drive a low-inertia pump: as a result, high-speed high-response control of hydraulic actuators is realized, thereby the quality of molding products obtainable from injection machines controlled by our system is higher compared with quality resulting from conventional systems. A series of our variable-speed pump system products adopting hybrid hydraulic pressure technology are available for NC lathes, machining centers and other industrial machines such as a press machine.

Electricity consumption and associated GHG emissions of the Jordanian industrial sector: Empirical analysis and future projection

In this paper, an empirical model is developed for electricity consumption of the Jordanian industrial sector based on multivariate linear regression to identify the main drivers behind electricity consumption. In addition, projection of electricity consumption for the industrial sector based on time series forecasting is presented. It was found that industrial production outputs and capacity utilization are the two most important variables that affect demand on electrical power and the multivariate linear regression model can be used adequately to simulate industrial electricity consumption with very high coefficient of determination. To illustrate the importance of integrating energy efficiency within national energy plans, the impact of implementing high-efficiency motors was investigated and found to be significant. Without such basic energy conservation and management programs, electricity consumption and associated GHG emissions for the industrial sector are predicted to rise by 63% in the year 2019. However, if these measures are implemented on a gradual basis, over the same period, electricity consumption and GHG emissions are forecasted to ascend at a lower rate with low/no cost actions.

자본회수계수를 고려한 고효율 생산설비의 경제성분석

제조업에서 생산설비에 사용되는 중요한 에너지원 중 하나는 전력에너지이며, 에너지 다소비 업종의 생산설비 즉, 플랜트에서는 사용하는 에너지의 절감과 효율 운전은 매우 중요한 관심사항이다. 본 논문에서는 생산 플랜트의 한 공정에서 가장 빈번히 사용되는 유도전동기를 모델로 하여 실제 진단, 계측을 통하여 측정값을 얻고, 기존의 운전 중인 설비들을 고효율 기기로 교체하였을 경우의 경제성을 분석하였다. 이를 위해서 현재 운전 중인 설비와 고효율설비로 교체하였을 경우에 대하여 각각 설비들의 연간 운전비용과 자본회수계수에 의한 연간 투자비용을 계산하였고, 이를 합산한 연간 총 운용비용을 비교하여 고효율설비의 경제적 타당성을 입증하였다.

Two-Phase SRM With Flux-Reversal-Free Stator: Concept, Analysis, Design, and Experimental Verification

The demand for high-efficiency electric motor drives at low cost is increasing, particularly, in high-volume applications, such as household appliances. Single- and two-phase machines are viable under such constraints. Between them, two-phase switched reluctance motor drives are preferred from the viewpoint of performance. This paper presents a novel two-phase switched reluctance machine (TPSRM) that is conceived for high-efficiency operation and full-load starting performance for any initial rotor position. The principle of operation of the proposed TPSRM and its unique features such as the flux-reversal-free stator for reducing core losses, the utilization of only two thirds of the stator core for each phase operation, and the resulting low noise are presented. The machine is analyzed with the 2-D finite-element analysis method. Self-starting in the proposed machine is developed with rotor pole shaping, and a unique technique to provide the desired torque characteristics is described. The effect of varying pole arcs, the number of turns per pole, asymmetric pole placement, and rotor pole shaping on torque and phase inductance is evaluated to find the best machine dimensions for a required performance as well as to understand qualitatively the influence of each variable on the machine performance. Experimental results from a 2.2-hp laboratory prototype correlate the performance predictions and validate the claims for this novel TPSRM.

Design of High-Power Density and Relatively High-Efficiency Flux-Switching Motor

A new class of electronically commutated brushless motor, namely, the flux-switching (FS) motor is gradually emerging in power tools and household appliances. This motor offers advantages of both high-power density and relatively high efficiency. There are a number of papers introducing this new class of motor. However, almost all of these papers focused on the analysis, and not the design, of the FS motor. Thus, this paper presents the design and analysis of the FS motor. Design equations are analytically derived for initial calculations of the main dimensions, number of turns, and inductances of the FS motor. Furthermore, a comprehensive time-stepping finite element (TSFE)-behavioral model is developed and utilized for detailed analysis and design refinements of a prototype 8/4-pole FS motor. Finally, test results of the prototype motor are provided to verify the design equations and efficacy of the design methodology.

Design Criteria for High-Efficiency SPM Synchronous Motors

This paper deals with the design criteria for a high-efficiency permanent magnet synchronous motor. The goal is not pursued by a trivial reduction of the electric and magnetic loadings (which decrease motor losses) but optimizing a set of motor design variables, without increasing the overall dimensions, which are typically imposed as design constraints. The effect of the number of slots and of the inner-to-outer diameter ratio on motor losses is investigated. The possibility of designing a stator with a tooth length lower than the total core length, using soft magnetic composites, is studied. Finally, a criterion is proposed to evaluate the convenience of using a nonoverlapping winding. An analytical approach is adopted so as to allows the obtained results to be useful for a wide variety of permanent magnet machines.

Recent Advances of Reluctance Torque Assisted Motors

The history of motor technology began with the discovery of electromagnetic induction by Faraday. Various kinds of motors were developed by the recent progress of the fundamental technology (magnetic structure, magnetic material, drive circuit, control method). Especially, motors using the reluctance torque have many advantages and some of them are used as high efficient motors. This paper overviews recent advances of reluctance torque assisted motors such as Switched Reluctance Motor (SRM), Synchronous Reluctance Motor (SynRM) and Interior Permanent Magnet Synchronous Motor (IPMSM).

Reducing Iron Loss by Decreasing Stress in Stator Core of Permanent Magnet Synchronous Motor

It is necessary to develop high efficiency motor, however, it comes a limit to increase efficiency because many motors already have very high efficiency. It is reported that iron loss of motor increase by shrink fit. Therefore, new motor shape is developed from a viewpoint of decreasing stator core stress caused by shrink fit. The relationship with iron loss and stator core stress is examined by the analysis, and the effect of new stator core is verified.

Exergy analysis of a MSF distillation plant

In this paper, a large MSF distillation plant in the gulf area is analyzed thermodynamically using actual plant operation data. Exergy flow rates are evaluated throughout the plant, and the exergy flow diagram is prepared. The rates of exergy destruction and their percentages are indicated on the diagram so that the locations of highest exergy destruction can easily be identified. The highest exergy destruction (77.7%) occurs within the MSF unit, as expected, and this can be reduced by increasing the number of flashing stages. The exergy destruction in the pumps and motors account for 5.3% of the total, and this also can be reduced by using high efficiency motors and pumps. The plant is determined to have a second law efficiency of just 4.2%, which is very low. This indicates that there are major opportunities in the plant to reduce exergy destruction and, thus, the amount of electric and thermal energy supplied, making the operation of the plant more cost effective.

Fixed Velocity Characteristics for an Electrical Vehicle with the New High-Efficiency Motor

Since d-c compound motor have wide industrial applications, theoretical and experimental research in such systems are assumed to be special importance. In previous work, we studied a new d-c compound motor which is suitable for the electronic vehicle and bicycle. This paper provides the fixed velocity characteristics for an electrical vehicle with the new high-efficiency motor. Experimental results show that the electric vehicle with new compund motor is more effective than the conventional one.

Exergy analysis of a combined RO, NF, andEDR desalination plant

A brackish water desalination plant in California that incorporates RO, NF, and EDR units was analyzedthermodynamically using actual plant operation data. Exergy flow rates were evaluated throughout the plant, and the exergy flow diagrams were prepared. The rates of exergy destruction and their percentage are indicated on the diagram so that the locations of highest exergy destruction can easily be identified. The analysis shows that most exergy destruction occurs in the pump/motor and the separation units. The fraction of exergy destruction in the pump/motor units is 39.7% for the RO unit, 23.6% for the NF unit, and 54.1 % for the EDR unit. Therefore, using high-efficiency pumps and motors equipped with VFD drives can reduce the cost of desalination significantly. The plant was determined to have a Second Law efficiency of 8.0% for the RO unit, 9.7% for the NF unit, and 6.3% for the EDR unit, which are very low. This indicates that there are major opportunities in the plant to improve thermodynamic: performance by reducing exergy destruction and thus the amount of electrical energy supplied, making the operation of the plant more cost effective.

Mechanism for the appearance of a high-efficiency Brownian motor with fluctuating potential

A version of a Brownian motor (system generating a unidirectional motion of a Brownian particle in an asymmetric fluctuating potential) is considered for the case where the potential consists of an asymmetric periodic component undergoing random shifts by a half-period L with a certain frequency and the potential of an external force F. The high efficiency of such a motor (ratio of the useful work against the load force F to the energy imparted to the particle due to the potential shifts) is due to a high and narrow barrier, as well as to a smooth arbitrarily shaped potential relief repeated with an energy shift on both half-periods L. Simple analytic expressions are obtained for the flux and efficiency as functions of the load force over a wide frequency range.

Optimizing operational efficiency in submersible pumps

In this article, Rob Montenegro, president of Pumpex Inc in the USA, and Nils Hökby, R&D director of Pumpex in Sweden, describe how their company, a specialist manufacturer of submersible pumps, has reduced pump maintenance costs and improved the effectiveness of its pumps by successfully combining high-efficiency hydraulic ends and motors with highly engineered user-friendly features.

分割コアモータにおける電磁鋼板選定の一考察

The segment stator core, high density winding coil, high-energy-product permanent magnet are indispensable technologies in the development of a compact and also high efficient motors. The conventional design method for the segment stator core mostly depended on experienced knowledge of selecting a suitable electromagnetic material, far from optimized design. Therefore, we have developed a novel design method in the selection of a suitable electromagnetic material based on the correlation evaluation between the material characteristics and motor performance. It enables the selection of suitable electromagnetic material that will meet the motor specification.

Study on a New Combination Method and High Efficiency Outer Rotor Type Permanent Magnet Motors

The segment stator core, high space factor coil, and high efficiency magnet are indispensable technologies in the development of compact and a high efficiency motors. But adoption of the segment stator core and high space factor coil has not progressed in the field of outer rotor type motors, for the reason that the inner components cannot be laser welded together. Therefore, we have examined a segment stator core combination technology for the purposes of getting a large increase in efficiency and realizing miniaturization. We have also developed a characteristic estimation method which provides the most suitable performance for segment stator core motors.

Performance Evaluation of the New High-Efficiency Motor for an Electrical Bicycle

Over the past years, a great deal of studies have been devoted to electrical bicycle, electrical vehicle, and so on. In previous work, we studied a new d-c compound motor which is suitable for the electronic bicycle on the level ground. In contrast to this, this paper considers the performance evaluation of the new high-efficiency motor for an electrical bicycle in detail. We try to show the experimental results of several driving condition. This directly leads us to the conclusion that a new d-c compound motor is higher efficiency than conventional one.

Piping potential

We are inclined to think of the pump and what it will do. But whatever the pump does, it is controlled and restrained by its pipework. Power is put into the system by the pump and that power is dissipated. The pump is a driving force; the pipework is a restraining force. As Trevor Benjamin explains, well-designed and correctly sized piping can contribute more to energy savings than fitting high efficiency motors or high efficiency pumps.

Analysis of magnetization of magnet in the rotor of line start permanent magnet motor

Line start permanent magnet motor (LSPM) is an effective model of a high-efficiency motor at a constant velocity. Post-assembly magnetization is necessary to reduce manufacture costs. The purpose of this paper is to design the magnetizing fixture and analyze the magnetization characteristics. First, the magnetizing fixture reducing the eddy current is designed. Second, the magnetization of NdFeB magnetized by the designed fixture is analyzed. The time-stepping finite-element method combined with the Preisach model is used to analyze the magnetizing magnetic field intensity and to calculate the magnetization vector. With the magnetization vector, the surface flux density and back-electromagnetic force of the LSPM are calculated and compared with experiment results, which, in turn, agree well with the analysis results.

The Biological Age of Prepubescent and Pubescent Children with Low and High Motor Efficiency

The aim of the study was to analyze the relations between some criteria of the biological age (growth age, biological proportional age) and motor efficiency in school-aged boys and girls (8-9 and 12-13 years old) with considerably above-average and considerably below-average total score of the test battery UNIFITTEST (6-60). The growth age results of 8 chosen groups (17-25 individuals in one group) showed that classifying the selected individuals into the normative height bands was in no relation to their age, sex or level of motor efficiency. As for the height-weight proportionality, the older the individuals were, the more of them belonged to the bands with relatively bigger weight. Analyzing the results of the biological proportional age, we did not find any significant differences between the groups of identical sex, age and different motor efficiency. Boys and girls with either low or high motor efficiency were mostly biologically average and biologically accelerated in the growth and development.