starting torque
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2021 ◽  
Author(s):  
Robert Adams ◽  
Jinjiang Xiao ◽  
Michael Cross ◽  
Max Deffenbaugh

Abstract Switched reluctance motors may be advantageous when used as the primary motor for an electric submersible pump system. They are less susceptible to jamming failures due to their high starting torque and ability to reverse direction. Driving these motors requires well-timed pulse waveforms and precise control of the motor based on its rotational position. It is demonstrated that the pulses required to drive switched reluctance motors can still be applied over along cable lengths. Additionally, the current at the surface can be used to monitor and control the operation of the motor downhole, even with long cable lengths separating the surface power source and downhole motor.


Author(s):  
Qiang Wang ◽  
Jigang Chen ◽  
Haili Zhou ◽  
Xuan Lyu ◽  
Zhanqi Hu

The starting torque of self-lubricating spherical plain bearings (SSPBs) is a key parameter for evaluating the performance of bearings. Therefore, the starting torque of SSPBs should be controlled to within an allowable range. In this paper, the starting torque generation mechanism is analyzed, and the critical load for the separation of the liner from the outer spherical surface of the inner ring is determined. A mathematical model of the starting torque is established; the experimental and theoretical results of the starting torque are compared and analyzed, and then the accuracy of the mathematical model is evaluated by the deterministic coefficient R2. The research reveals that a critical load exists for the starting torque. Below the critical load, the starting torque is dependent on the outer spherical radius of the inner ring, bearing wrap angle, and liner parameters such as the compressive elastic modulus, friction coefficient, and precompression of the liner; however, the starting torque is independent of the radial load. Above the critical load, the starting torque is also dependent on the radial load. The research results provide a theoretical basis for the design and application of bearings.


Author(s):  
А.Б. Каракаев ◽  
А.В. Костенко

Статья посвящена разработке методики проектирования однофазного асинхронного электродвигателя без внешних фазосдвигающих устройств для систем судовой автоматики. Отмечается, что существующие на сегодняшний день известные методики расчёта микромашин не учитывает потерь в стали, что приводит к значительным погрешностям при расчёте двигателя. Авторами предлагается применять разработанную уточненную методику расчёта двигателя для дальнейшего его проектирования. Отмечается, что из выявленных в работе зависимостей важнейшей является зависимость пускового момента от электрического угла между осями обмоток 1 и 44 - α. Где выбор не оптимального электрического угла - крайне негативно сказывается на величине пускового момента однофазной микромашины. Для пояснения особенностей определения активной части двигателя авторами строится график зависимости наружной поверхности и потерь от полезной мощности. Также, в статье авторы приводят номограммы, позволяющие принимать проектировочные решения не только на основания расчёта, но и графоаналитическим методом. Результатом работы является получение новой методики расчёта и проектирования однофазной микромашины для систем судовой автоматики, используя для расчёт математическую модель, полученную с помощью методов планирования эксперимента. The article is devoted to the development of a design technique for a single-phase asynchronous electric motor without external phase-shifting devices for ship automation systems. It is noted that the currently known methods for calculating micromachines do not take into account losses in steel, which leads to significant errors in calculating the engine. The authors propose to apply the developed refined methodology for calculating the engine for its further design. It is noted that of the dependences identified in the work, the most important is the dependence of the starting torque on the electric angle between the axes of the windings 1 and 44 - α. Where the choice of a non-optimal electrical angle has an extremely negative effect on the magnitude of the starting torque of a single-phase micromachine. To clarify the features of determining the active part of the engine, the authors build a graph of the dependence of the outer surface and losses on the net power. Also, in the article, the authors provide nomograms that allow making design decisions not only on the basis of calculation, but also by the graphical analytical method. The result of the work is to obtain a new methodology for calculating and designing a single-phase micromachine for ship automation systems, using for the calculation a mathematical model obtained using experimental planning methods.


2021 ◽  
Vol 942 (1) ◽  
pp. 012003
Author(s):  
V V Dmitrieva ◽  
P E Sizin ◽  
A A Sobyanin

Abstract The purpose of the work is to justify the need for a smooth start of the conveyor belt. Based on the technological features of the transportation process, the direct start of the conveyor with a loaded undercarriage entails an increase in inertial forces, overload of the traction chains and the drive. Due to the increased starting torque, there is a danger of slipping, the occurrence of an oscillatory transient of the escaping branch of the tape, slipping between the tape and the drive drum. This leads to significant wear of the tape and breakdowns of other equipment, which requires high repair costs. With a smooth start of the conveyor, the acceleration lasts longer, but the movement of the concentrated masses of the belt is more consistent, less oscillatory, which indicates less dynamic forces in the belt. Also, with a smooth start, energy losses in the engine and its heating are reduced. The main results of the work - the transients in the currents of the stator and rotor, in the speed of rotation of the motor and in the speed of movement of the conveyor belt were obtained. The developed model allows us to investigate the dynamic operating modes of the engine and the mechanical part of the conveyor, to analyze the forces arising in the belt during direct and smooth start of the conveyor, to evaluate the slip of the belt and the magnitude of the traction factor. Conclusions - the results of this work should be the basis for controlling the tension in the belt and maintaining the traction factor of the conveyor belt in the start-brake operating modes. In addition, the results obtained can be used in the development of a belt speed control system depending on the amount of random freight traffic entering the conveyor.


Author(s):  
Deekshitha S Nayak ◽  
R. Shivarudraswamy

AbstractThe typical mixer grinders are universal motor, which operates on alternating current supply because of the higher starting torque characteristics and easy speed control. The absence of brushes in the Brushless DC (BLDC) motor and noise reduction improves its life and makes it perfectly suited for mixer grinder. The mathematical modelling and experimental demonstration of a conventional universal motor and proposed simulated model of BLDC motor was analysed using the MATLAB/Simulink. The loss and efficiency analysis of the permanent magnet BLDC and universal motor in the application of a mixer grinder are presented in this paper.


2021 ◽  
Vol 13 (16) ◽  
pp. 9151
Author(s):  
Mintra Trongtorkarn ◽  
Thanansak Theppaya ◽  
Kuaanan Techato ◽  
Montri Luengchavanon ◽  
Chainuson Kasagepongsarn

The application of wind turbine technology in low wind speed regions such as Southeast Asia has recently attracted increased attention. Wind turbines are designed as special structures with low starting torque, and many starting torque minimization processes exist for permanent magnet synchronous generators (PMSGs). Plurality is applied to decrease the starting torque in radial flux permanent magnet disk generators. The most popular starting torque minimization method uses a magnet skew technique. When used at 20°, this technique reduced starting torque by 4.72% (on load) under 500 rpm at 50 Hz for 120 min. By contrast, a PMSG with magnet skew conditions set at under 2° reduced electrical power by 3.86%. For high-speed PMSGs, magnet skew techniques affect the generation of heat in the coils (stator), with heat decrease at the middle of the coil, on its surface and between the coils at 2.90%, 3.10% and 2.40%, respectively. PMSGs were installed in vertical axis wind turbines (VAWTs), and heat generation in relation to wind speed and electrical power was assessed. Magnet skew techniques can be used in PMSGs to reduce staring torque, while skew techniques also reduce electrical power and heat generated at the stator.


MIND Journal ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 73-88
Author(s):  
SENI NURJANAH ◽  
NASRUN HARIYANTO ◽  
SABAT ANWARI

AbstrakMesin CNC digunakan untuk membuat kerangka pesawat terbang, motor induksi sebagai tenaga penggerak diatur kecepatan putarnya untuk menghasilkan torka sesuai kebutuhan dikendalikan oleh VSD. Pengendalian VSD pada mesin CNC menggunakan software PSIM untuk mengetahui karakteristik mesin CNC dengan tegangan dan frekuensi yang divariasikan agar menghasilkan torka konstan. Analisis karakteristik motor induksi digunakan rangkaian pengganti dan perhitungan matematis. Untuk mengetahui rentan kerja mesin CNC maka arus starting 61,83Ampere; torka starting 23,28N.m; torka maksismum 14,1N.m; putaran sinkron 1500rpm. Pengolahan data dilakukan secara matematis, pada pengukuran mendapatkan torka 35N.m sedangkan simulasi beban 30% menghasilkan torka 4.2N.m; beban 60% menghasilkan torka 8.3N.m; beban 90% menghasilkan torka 12.5N.m. Dapat disimpulkan kendali V/f menghasilkan torka konstan sepanjang pengaturan kecepatan putar. Kata kunci: PSIM, Variable Speed Drive, Torka Motor Induksi, Mesin CNCAbstractCNC machines are used to make aircraft frames, the induction motor as the driving force is set to rotate its speed to produce torque as needed, controlled by a variable speed drive. VSD control on CNC machines uses PSIM software to determine the characteristics of CNC machines with varied voltages and frequencies to produce constant torque. Analysis of the characteristics of the induction motor used a replacement circuit and mathematical calculations to determine the working range of the CNC machine. Then the starting current is 61.83Amperes; starting torque 23.28N.m; maximum torque 14.1N.m; synchronous speed 1500rpm. Data processing is done mathematically, the measurement gets 35N.m of torque while the 30% load simulation produces 4.2N.m of torque; 60% load produces 8.3N.m torque; 90% load produces 12.5N.m of torque. It can be concluded that the V/f control produces constant torque throughout the rotational speed setting.Keywords: PSIM, Variable Speed Drive, Induction Motor Torque, CNC Machine


2021 ◽  
pp. 1-23
Author(s):  
K.A.R. Ismail ◽  
Thiago Canale ◽  
Fatima M. Lino

Abstract Small wind turbines usually suffer from poor efficincy, low power and lack of public incentives. This study is focused on investigating the effects of the geometry of the airfoil sections and blades on the starting torque and minimum wind speed for energy generation. The Blade Element Momentum Theory is used to develop a numerical code where the airfoil S832 is used as a reference for comparison and validation. The investigated parameters include three airfoil sections Joukowski J9.513, Gottingen GO447, and S832, linear and elliptic chord distributions, linear twist angle distribution and multiple airfoil sections along the blade. The results show that large local solidity ratio at the intermediate region of elliptic chord distribution produces significant reduction in the local generated torque of about 5-21% and that the linear chord distribution along the blade length increases the torque by about 27-77% and thus permits lower starting wind speeds. For rotors with high solidity ratio as in the case of elliptic chord distribution, the distribution of twist angle for constant angle of attack reduces the generated torque by about 13-19%. The J9.513 airfoil based rotor shows 20-35% more start torque than the S832 and GO447 airfoils based rotors. The linear chord distribution is shows better results for all the three airfoils based rotors. The linear twist angle distribution increases significantly the start torque of the rotors with the proposed airfoils sections. The three airfoils S832, GO447 and J9.513with linear twist angle distribution are viable options for small wind turbines. The J9.513 with linear chord and linear twist angle distribution shows the lowest wind speed for electricity generation. The use of multiple airfoils on the blade length shows marginal improvement of the starting torque.


Author(s):  
Keshav Alias Deepesh Ramesh Shetkar ◽  
Tejas Sadanand Pethker ◽  
Saurabh Shrikant Savant ◽  
Nilabh Rajendraprasad Vishwakarma

The concept of Automatic Manual Transmission (AMT) is picking up speed in India after the launch of the Maruti Suzuki Celerio. But very few of the two-wheeler manufacturers in the world have tried to implement the AMT concept in a motorcycle. There are gearless motorcycles available which use a Continuously Variable Transmission (CVT) and a Centrifugal clutch, but this setup is very inefficient compared to a positive gear drivetrain. Thus these gearless motorcycles get low mileage and are also more expensive to manufacture. Geared motorcycles, on the other hand, have better starting torque, greater mileage and a higher span of gear ratios. They are also cheaper, but the average buyer is discouraged by the complexity of the operation. Even those familiar with riding a motorcycle do not shift optimally to obtain the best mileage/performance. The aim of this paper is to present an innovative AMT system developed and implemented on a manual geared motorcycle having a sequential constant-mesh gearbox with a multi-plate clutch. This was carried out by interfacing the manual gear shifting motorcycle with a microcontroller and using an electronic actuation mechanism to make it an automatic gear shifting motorcycle. The significant steps of this project would involve the sensor readouts of the parameters necessary, the actuation of the controls and, most importantly, the algorithm for the optimal shift points for a given motorcycle. These would be obtained experimentally and using the manufacturer data, if available. This AMT setup has been successfully developed and implemented. This setup can then be applied to any geared motorcycle with minimal structural changes without any modification to its existing gearbox. This converts the manual geared motorcycle into the automatic gear shifting motorcycle having better fuel economy and lower maintenance costs as compared to the conventional CVT motorcycles.


2021 ◽  
Vol 18 (1) ◽  
pp. 70-75
Author(s):  
E.C. Abunike ◽  
G.D. Umoh ◽  
I.E. Nkan ◽  
O.I. Okoro

The switched reluctance motor (SRM) is among the special purpose electric machine family. It is simple in construction and avoids use of magnet so it is cheap to manufacture. The magnetic characteristics and simulation of three phase 12/8 switched reluctance motor (SRM) for enhanced starting torque is presented. The motor was analyzed using finite element technique (FET) and it was improved by focusing on the impact of important geometrical parameters on torque and efficiency. From the simulated results, the motor attained maximum efficiency of 91.7% at a speed of 1648.6 rpm and recorded a maximum torque of 321.1 Nm at a speed of 34.4 rpm. The magnetic flux lines and densities were also recorded. The maximum and minimum magnetic flux lines of the motor as observed were 1.2x10-3 Wb/m and -8.5x10-4 Wb/m respectively while the respective values of the maximum and minimum magnetic flux density of the motor were 3.8x10-1 T and 2.11x10-9 T. The results show that most of the field energy is confined within the motor and also concentrated in the air gap region of the motor. Dynamic analysis of the motor was performed for 0.02 s at a damping coefficient of 0.71 μNms/rad. The results showed that the motor has lower torque ripple. The preference to use this type of motor where high speed operation and better starting torque are needed has been highlighted in this study. Keywords:  Switched reluctance motor, static characteristics, transient analysis, torque, magnetic flux


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