scholarly journals A method of thrust ripple suppression for long stator linear synchronous motor

2018 ◽  
Vol 4 (2) ◽  
pp. 30-44
Author(s):  
Siyuan Mu ◽  
Jinsong Kang ◽  
Shuo Wang ◽  
Yusong Liu ◽  
Cuiwei He
Keyword(s):  
High Speed ◽  
Reference Frames ◽  
High Efficiency ◽  
Synchronous Motor ◽  
Low Noise ◽  
Good Prospect ◽  
Maglev Train ◽  
Harmonic Current ◽  
Current Harmonics ◽  
Linear Synchronous Motor

With the advantages of high speed, low noise and high efficiency, the electromagnetic suspension (EMS) type maglev train has a good prospect in railway transportation. It is based on the long stator linear synchronous motor (LSLSM). However, due to cogging effect, end effect and the harmonics in the stator current and flux density distribution around the air-gap, the thrust generated by the LSLSM fluctuates. The thrust ripple brings noise, drop of control accuracy, even causes the resonance of train. In this paper, the thrust ripple produced by the cogging effect and flux linkage harmonics is analyzed. Then a method of harmonic current injection is proposed to compensate cogging force and reduce the thrust ripple, without influence the decoupling control of traction and suspension system. The injected current harmonics are controlled under multiple rotating reference frames independently. Finally, based on voltage equations of harmonics, the decoupled harmonic current controllers with harmonic voltage feedforward are designed, which improve the performance of current harmonics response and thrust ripple suppression. Simulation results on Simulink verify the effectiveness of proposed thrust ripple suppression method for LSLSM.

A Study on the Structure of Linear Synchronous Motor for 600km/h Very High Speed Train

2013 ◽  
Vol 416-417 ◽  
pp. 317-321 ◽  
Author(s):  
Chan Bae Park ◽  
Byung Song Lee ◽  
Jae Hee Kim ◽  
Jun Ho Lee ◽  
Hyung Woo Lee
Keyword(s):  
High Speed ◽  
Type System ◽  
Synchronous Motor ◽  
Propulsion System ◽  
Contact Method ◽  
High Speed Train ◽  
Maglev Train ◽  
Railway Systems ◽  
Linear Synchronous Motor ◽  
Very High

Recently, an interest in a hybrid system combining only the merits of the conventional wheel-rail system and Maglev propulsion system is growing as an alternative to high-speed maglev train. This hybrid-type system is based on wheel-rail method, but it enables to overcome the speed limitation by adhesion because it is operated by a non-contact method using a linear motor as a propulsion system and reduce the overall construction costs by its compatibility with the conventional railway systems. Therefore, a comparative analysis on electromagnetic characteristics according to the structural combinations on the stator-mover of Linear Synchronous Motor (LSM) for Very High Speed Train (VHST) maintaining the conventional wheel-rail method is conducted, and the structure of coreless superconducting LSM suitable for 600 km/h VHST is finally proposed in this paper.

scholarly journals A special excitation system for analysis of coupling characteristics of thrust and levitation force of maglev train

2018 ◽  
Vol 4 (2) ◽  
pp. 45-51
Author(s):  
Jian Rao ◽  
Ke Wang ◽  
Boyu Wang ◽  
Qiongxuan Ge ◽  
Liming Shi ◽  
...  
Keyword(s):  
High Speed ◽  
Levitation Force ◽  
Synchronous Motor ◽  
Air Gap ◽  
Field Variation ◽  
Maglev Train ◽  
Excitation System ◽  
Linear Synchronous Motor ◽  
Levitation System ◽  
Coupling Characteristics

Background: In the maglev train propelled by long stator linear synchronous motor (LSLSM), the thrust characteristics are one of important points to evaluate the performance of the system. However, coupling effect exists between the propulsion and levitation system. Therefore, the interference from the levitation system must be considered when the propulsion system is designed. Aim: The article focus on the analysis of coupling characteristics of thrust and levitation force of maglev train, and a special excitation system is designed for the study. Methods: In order to study the thrust performance under the fluctuating air gap field under laboratory conditions, a rotating synchronous motor has been designed to imitate the long stator linear synchronous motor applied in high speed maglev train. And a special excitation system is designed for the rotating synchronous motor, which can simulate the fluctuation of the exciting current during the actual operation of maglev train. The air gap of the rotating synchronous motor is kept as constant, and the fluctuating excitation current is added to the excitation winding of the rotating synchronous motor, thus the simulation of air gap magnetic field variation is achieved. Results: The special excitation system of the experimental motor is introduced in detail. Conclusion: The relationship between thrust and levitation force of long stator linear synchronous motor (LSLSM) in maglev train is strong coupling, non-linear, and dynamic. Complete decoupling of thrust and levitation force is not easy to be achieved. The experimental platform has been built to study the coupling characteristics of thrust and levitation force of maglev train.

On Study of High Speed Permanent Magnet Synchronous Motor without Iron Core

2013 ◽  
Vol 706-708 ◽  
pp. 882-887
Author(s):  
Ji Zhu Liu ◽  
Yang Jun Wang ◽  
Tao Chen ◽  
Ming Qiang Pan ◽  
Li Guo Chen ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
High Efficiency ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Iron Core ◽  
Torque Density ◽  
Optimized Model ◽  
Low Efficiency ◽  
Design And Manufacture

Iron loss will be rapidly increased when the permanent magnet iron core synchronous motor runs at a high speed, which makes the motor produce so much heat that causes low efficiency of the motor and even burns out the motor. The iron-core-free permanent magnet synchronous motor remedies this defect and has a high efficiency at high speed. This article makes a comparative analysis on the iron-core-free permanent magnet synchronous motor torque density with different slot engagement classifications. The paper puts forward an optimized model of permanent magnet synchronous motor without the iron core. The technology of the permanent magnet synchronous motor without iron core is studied based on this model which provides a method to design and manufacture the iron-core-free permanent magnet synchronous motor.

A linear synchronous motor for high-speed ground transport

1974 ◽  
Vol 10 (3) ◽  
pp. 435-438 ◽  
Author(s):  
G. Slemon ◽  
R. Turton ◽  
P. Burke
Keyword(s):  
High Speed ◽  
Synchronous Motor ◽  
Linear Synchronous Motor
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