scholarly journals LINE-START SYNCHRONOUS MOTOR A VIABLE ALTERNATIVE TO ASYNCHRONOUS MOTOR

2020 ◽  
Vol 19 (1) ◽  
pp. 039
Author(s):  
Vasilija Šarac

Advancements in power electronics that contributed to the easier starting of synchronous permanent magnet motors have increased the significance of this type of motors, widely known as not–self-starting motors. However, power electronics, which is necessary, for the starting of the synchronous motor contributed also to the complexity of this type of motor drives as well as to increased operational and maintenance cost. The line-start synchronous motors have gained the popularity during recent years as a viable alternative to asynchronous motors due to an easy line starting similar to the asynchronous motors and good operational parameters such as high efficiency and power factor. The paper presents the design of a line-start synchronous motor, derived from an asynchronous motor, by redesigning the rotor with flux barriers and permanent magnets. The computer models for calculating parameters and operating characteristics of both motors were modeled and the accuracy of the obtained results was verified by comparison with experimental data. Motor transient characteristics of speed, current and torque for the line starting of the both motors, when they were fed with the voltage from the network, were determined as well. The obtained transient characteristics of both motors were compared and adequate conclusions regarding line starting of both motors were derived. The newly derived synchronous motor for line starting has good operational characteristics such as increased efficiency, power factor and starting torque compared with the respected parameters of the asynchronous motor, good transient and steady-state operating characteristics and good dynamic response at sudden load change.

2021 ◽  
Vol 69 (1) ◽  
pp. 11-18
Author(s):  
Vasilija SARAC

Energy efficient motors are the key components of each industrial process. In the energy demanding society, requiring the energy efficient consumers, the line-start synchronous motor has gained more and more popularity due to the high efficiency and power factor combined with good operational characteristics. The disadvantages of the synchronous motors such as inability of starting without the inverter has been largely overcame with this type of the motor. However, the proper design of line-start motor regarding permanent magnets and the squirrel cage winding is crucial for motor starting and synchronization capability. In this paper, the line-start synchronous motor is derived from the asynchronous motor by redesigning the rotor. The obtained performance characteristics of the synchronous motor is compared with the data of the asynchronous motor (the analytical, measurements and from the motor producer) and they show reasonable agreement. The derived model of the synchronous motor is numerically modelled for obtaining the magnetic flux density distribution in the motor cross-section. The analysis and comparison is completed by obtaining the transient characteristics of both types of the motors. The designed synchronous motor has proven to have good starting and synchronization capabilities combined with the high efficiency. The dynamic response at sudden load changes is within expected limits.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 318
Author(s):  
Chunyan Li ◽  
Fei Guo ◽  
Baoquan Kou ◽  
Tao Meng

A permanent magnet synchronous motor (PMSM) based on the principle of variable exciting magnetic reluctance (VMRPMSM) is presented. The motor is equipped with symmetrical non-magnetic conductors on both sides of the tangential magnetized permanent magnets (PMs). By placing the non-magnetic conductor (NMC), the magnetic reluctance in the exciting circuit is adjusted, and the flux weakening (FW) of the motor is realized. Hence, the NMC is studied comprehensively. On the basis of introducing the motor structure, the FW principle of this PMSM is described. The shape of the NMC is determined by analyzing and calculating the electromagnetic force (EF) acting on the PMs. We calculate the magnetic reluctance of the NMC and research on the effects of the NMC on electromagnetic force, d-axis and q-axis inductance and FW performance. The critical speeds from the test of the no-load back electromotive force (EMF) verify the correctness of the NMC design. The analysis is corresponding to the test result which lays the foundation of design for this kind of new PMSM.


2009 ◽  
Vol 10 (6) ◽  
pp. 455-476 ◽  
Author(s):  
Souhil Seghir-Oualil ◽  
Souad Harmand ◽  
Daniel Laloy ◽  
Olivier Phillipart

Author(s):  
S.Yu. Trudnev ◽  

The most widely used single-phase asynchronous motors are described and also substitution and vector dia-grams are reviewed. Theoretical and mathematical descriptions of processes of controlling and enabling asynchronous modes of operation were provided, on the basis of which computer models of a single-phase asynchronous motor in static and dynamic modes was created in the Matlab program. Experiments were per-formed on the real and virtual models, and the data obtained were processed and compared to confirm the adequacy of the developed virtual model.


2019 ◽  
Vol 104 ◽  
pp. 01006
Author(s):  
Maxim Filimonov ◽  
Nicolay Karnaukhov ◽  
Eugeny Lukyanov ◽  
Dmitry Smyatsky ◽  
Roman Mironenko

this article the energy efficient frequency way of starting of production mechanisms electrical drive with low power asynchronous motors (from 90 Wt to 5 kWt) is proposed. To provide this With the goal of electrical losses decreasing during asynchronous motor starting the Pontryagin Maximum Principle have been applied by the authors when analysing of two-mass model of production mechanism frequency controlled electrical drive. In result of calculations for frequency controlled electrical drive of production mechanism with 90 Wt power asynchronous motor of the model 4AA50A2 Dependencies of amplitude and frequency of supply voltage by the time are obtained. These dependencies confirm possibility of decreasing the electrical power losses with different values of motor shaft load torques. In compare with the other ways of asynchronous motor starting (for example U/f=const) they allow to decrease the electrical losses more then two times in nominal mode.


2019 ◽  
Vol 14 (2) ◽  
pp. 77-82
Author(s):  
Рустам Аипов ◽  
Rustam Aipov ◽  
Рустам Галиуллин ◽  
Rustam Galiullin ◽  
Раушан Нугуманов ◽  
...  

In modern flour production, the preservation of all vitamins and minerals in it is relevant. Minerals and vitamins are stored in flour, ground from whole grains. In the stone mills, the grain is subjected to repeated exposure to the working surfaces of the millstones, as a result of which the flour contains a large percentage of the most important components of the grain. The stone mill’s drive should provide a low rotational speed of the mills (peripheral speed up to 10 m/sec.) and the possibility of smooth control of its speed and torque without reducing the performance of the mill. From this point of view, it is promising to use in the mill’s drive, instead of asynchronous motors, rotation with additional devices (gearboxes, belt drives, V-belt drives, etc.) of flat asynchronous electric drives. The article suggests possible variants of technical solutions for stone mills with flat electric drives. It was concluded that the use of a flat asynchronous motor in the mill’s drive allows not only smoothly adjusting the frequency and torque of the millstones, but also because of the presence of edge effects, to prevent flour sticking in the millstone working zone. Compiled with the possibility of solving by analytical methods a mathematical model of mill’s drive, based on a flat electric drives, taking into account the longitudinal edge effect, the strength of viscous (internal) and dry (external) friction. The mechanical characteristics of the drive were found when moving the flat electric drives inductors and the dependencies of the change in the mill productivity on the millstone rotation frequency when grinding various grains, changing the fill factor of the grinding zone and the gap between the millstones were obtained.


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