Analysis of Mid-Low Speed Maglev Suspension Dynamic Performance in Guideway Step Disturbance

2017 ◽  
Author(s):  
Siyang Zhou ◽  
Jie Li
Keyword(s):  
Dynamic Performance ◽  
Low Speed ◽  
Step Disturbance

A Novel Fuzzy Adaptive Speed Estimator for Space Vector Modulated DTFC of AC Drives

2011 ◽  
Vol 403-408 ◽  
pp. 4850-4858
Author(s):  
Jagadish H. Pujar ◽  
S. F. Kodad
Keyword(s):  
Fuzzy Control ◽  
Adaptive Systems ◽  
Dynamic Performance ◽  
Research Work ◽  
Speed Control ◽  
Adaptation Mechanism ◽  
Low Speed ◽  
Ac Drives ◽  
Control Scheme ◽  
Speed Estimator

In this paper a novel sensorless speed control scheme of Induction Motor (IM) by means of Direct Torque Fuzzy Control (DTFC), PI-type fuzzy speed regulator and fuzzy based Model Reference Adaptive Systems (MRAS) speed estimator strategies has been proposed, which seems to be a boom in sensorless speed control schemes of AC drives. Normally, the conventional sensorless speed control performance of IM drive deteriorates at low speed. Hence the attention has been focused to improve the performance of the IM drive at low speed range as well, by implementing fuzzy control strategies. So, this research work describes a novel adaptive fuzzy based speed estimation mechanism which replaces the conventional PI controller used in MRAS adaptation mechanism. The proposed scheme is validated through extensive numerical simulations on MATLAB. The simulated results signify that the proposed control scheme provides satisfactory high dynamic performance and robustness during low speed operations of IM drive compare to conventional sensorless speed estimator of DTFC scheme.

scholarly journals Stator Flux Observer for Induction Motor Based on Tracking Differentiator

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Dafang Wang ◽  
Zhenfei Hu ◽  
Cheng Zhu ◽  
Chuanwei Zhou ◽  
Yajing Xie
Keyword(s):  
Dynamic Error ◽  
Dynamic Performance ◽  
Direct Torque Control ◽  
Torque Control ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Speed ◽  
Tracking Differentiator ◽  
Low Pass ◽  
Stator Flux

Voltage model is commonly used in direct torque control (DTC) for flux observing of asynchronous motor. In order to improve low-speed and dynamic performance of the voltage model, a modified low-pass filter (LPF) algorithm is proposed. Firstly, the tracking differentiator is brought in to modulate the measured stator current, which suppresses the measurement noise, and then amplitude and phase compensation is made towards the stator electromotive force (EMF), after which the stator flux is obtained through a low-pass filter. This method can eliminate the dynamic error of flux filtered by LPF and improve low-speed performance. Experimental results demonstrate effectiveness and improved dynamic performance of such method.

scholarly journals Experimental investigation on vibration characteristics of the medium–low-speed maglev vehicle–turnout coupled system

2021 ◽  
Author(s):  
Miao Li ◽  
Dinggang Gao ◽  
Tie Li ◽  
Shihui Luo ◽  
Weihua Ma ◽  
...  
Keyword(s):  
Dynamic Performance ◽  
Field Tests ◽  
Coupled System ◽  
Vibration Characteristics ◽  
Operating Conditions ◽  
Transport Systems ◽  
Ride Quality ◽  
Optimized Design ◽  
Line System ◽  
Low Speed

AbstractThe steel turnout is one of the key components in the medium–low-speed maglev line system. However, the vehicle under active control is prone to vehicle–turnout coupled vibration, and thus, it is necessary to identify the vibration characteristics of this coupled system through field tests. To this end, dynamic performance tests were conducted on a vehicle–turnout coupled system in a medium–low-speed maglev test line. Firstly, the dynamic response data of the coupled system under various operating conditions were obtained. Then, the natural vibration characteristics of the turnout were analysed using the free attenuation method and the finite element method, indicating a good agreement between the simulation results and the measured results; the acceleration response characteristics of the coupled system were analysed in detail, and the ride quality of the vehicle was assessed by Sperling index. Finally, the frequency distribution characteristics of the coupled system were discussed. All these test results could provide references for model validation and optimized design of medium–low-speed maglev transport systems.

Direct Torque Control of the Genetic Neural Network under the Low-Speed

2012 ◽  
Vol 466-467 ◽  
pp. 694-697
Author(s):  
Lian Zhang ◽  
Wei Lai ◽  
Jie Li
Keyword(s):  
Neural Network ◽  
Structure Learning ◽  
Dynamic Performance ◽  
Asynchronous Motor ◽  
Direct Torque Control ◽  
Optimal Solution ◽  
Torque Control ◽  
Bp Network ◽  
Low Speed ◽  
Genetic Neural Network

For the direct torque control of asynchronous motor rapid response and speed ripple, this article proposes the genetic neural network algorithm based on the model of stator flux, to achieve the selecting of switch state under the low-speed. Using the global optimization and search method of genetic algorithm obtains global optimal solution, while the connection weights and network structure learning improve the training effectiveness of neural network, so that the BP network has better adaptive characteristic. The effectiveness of the design is verified by the simulation, and it shows that the speed control system has good dynamic performance and steady state performance under the low-speed.

Dynamic Performance Simulation of Hydraulic Transmission for Low Speed Vertical Axis Marine Current Turbine Using MATLAB Simulink

2015 ◽  
Vol 74 (5) ◽  
Author(s):  
Atef S. Souf-Aljen ◽  
Adi Maimun ◽  
Rahim Samad ◽  
Jaswar Jaswar
Keyword(s):  
Fossil Fuels ◽  
Dynamic Performance ◽  
Hydraulic Drive ◽  
Vertical Axis ◽  
Ocean Energy ◽  
Matlab Simulink ◽  
Low Speed ◽  
Drive Trains ◽  
Marine Current ◽  
Reliability And Robustness

For Malaysia, ocean energy can be the best resource of green marine renewable energy. This is for the reason, the generation of the electricity by burning of fossil fuels produces undesired greenhouse gases and moreover the reserves of fossil fuels are being depleted and there is no accurate way to determine how much still remains. Turbines using hydraulic drive are being used for generating electricity by some manufacturers in the wind industry as an alternative to gearbox drive-trains because of reliability issues. Likewise, in the marine renewable sector, hydraulic-drive is an attractive option in terms of improved system efficiency, reliability and robustness. This paper presents a time domain simulation of hydraulic transmissions for Low Speed Vertical Axis Marine Current Turbines (VACT) using MATLAB Simulink software. These turbines are applied to harness marine current energy because of their relative simplicity and represent a promising technology to exploit low speed currents due to their small plants with reduced installation and maintenance costs. 

Mixed thermal elastohydrodynamic lubrication analysis with dynamic performance of aero ball bearing during start-up and shut-down

2020 ◽  
Vol 234 (6) ◽  
pp. 873-886
Author(s):  
Xiujiang Shi ◽  
Jiqiang Wu ◽  
Bin Zhao ◽  
Xuan Ma ◽  
Xiqun Lu
Keyword(s):  
Boundary Lubrication ◽  
Ball Bearing ◽  
Dynamic Performance ◽  
Elastohydrodynamic Lubrication ◽  
Heavy Load ◽  
Low Speed ◽  
Start Up ◽  
Ball Number ◽  
Lubrication Properties ◽  
Load Conditions

In this study, a coupling model is developed to include the aero ball bearing dynamic performance in the mixed thermal elastohydrodynamic lubrication analysis, and the low-speed and heavy-load conditions during start-up and shut-down are involved. Based on the bearing quasi-dynamics, the inside motion state of the main loading surface is obtained, and the mixed thermal elastohydrodynamic lubrication is conducted to get bearing lubrication state and properties. The numerical lubrication model under low-speed and heavy-load conditions is validated against published tested data, which reveal well consistency in central film thickness. The lubrication properties between a single ball and inner race during start-up have been studied, which indicate the lubrication film transforms from boundary lubrication to unsafe mixed thermal elastohydrodynamic lubrication, and then goes into safe lubrication. The lubrication properties of the balls at different azimuths have been investigated during shut-down and compared with those in start-up, which have a similar opposite changing trend, but not a simple invertible process. The time in boundary lubrication region during shut-down is shorter, and the ball number in boundary lubrication region gets less, which means the lubrication properties are relatively better. At last, the parametric study on mixed thermal elastohydrodynamic lubrication properties during shut-down has been carried out. It is found that the small bearing curve coefficient and increasing ball number can reduce the boundary lubrication time and improve the bearing lubrication.

A Direct Torque Control Driven Vessel Actuator Device

2014 ◽  
Vol 651-653 ◽  
pp. 593-597
Author(s):  
Hui Lue Jiang ◽  
Bo Liu ◽  
Chuan Dao Liu
Keyword(s):  
Dynamic Performance ◽  
Complex Structure ◽  
Direct Torque Control ◽  
Torque Ripple ◽  
Torque Control ◽  
Low Speed ◽  
Simulation Results ◽  
Low Efficiency ◽  
The Impact

Actuator is one of the most important auxiliary mechanisms used to control the ship heading. Focused on the existed shortages of conventional hydraulic driven vessel actuator as complex structure, low efficiency and response etc, by the analysis of torque variation to access the impact of direct torque control and design an actuator used direct torque control of which is simple and easy to implement. Simulation results show that this scheme can reduce system without dynamic performance, low-speed operation to expand the scope of the system, reducing the torque ripple, while improving the low-speed torque of the motor.

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