scholarly journals Vector Control and Modeling of Modular Multilevel High Voltage Converter for Rail Vehicle Traction

2022 ◽  
Vol 16 ◽  
pp. 517-524
Author(s):  
Yu Zheng ◽  
Changxiu Yang ◽  
Tiefeng Peng ◽  
Liujian Zhang
Keyword(s):  
Vector Control ◽  
High Voltage ◽  
Frequency Conversion ◽  
High Reliability ◽  
Open Loop ◽  
Economic Life ◽  
Traction Motor ◽  
Loop Control ◽  
Rail Vehicle ◽  
Multi Level

Rail transit plays an important role in the social and economic life of China and even all countries in the world, especially some populous countries or regions. The traction drive system of rail vehicle provides three-phase AC with adjustable voltage and frequency for the traction motor, controls the speed and torque of the traction motor, and then controls the operation of the vehicle. The modular multilevel converter has the advantages of low harmonic, good power quality of output waveform, high reliability, no input filtering and power compensation, and is suitable in the field of frequency conversion. In this work, the open-loop scalar control and vector closed-loop control of modular multi-level high-voltage inverter were adopted. It was found that driven by modular multi-level variable frequency vector control system, asynchronous motor not only has less harmonic content of voltage and current waveform, but also its speed regulation characteristics have been improved.

Modeling and Simulating of Frequency Conversion Soft Start System Based on SPWM

2014 ◽  
Vol 1049-1050 ◽  
pp. 1102-1106
Author(s):  
Yu Qian Song ◽  
Shou Dong Shi
Keyword(s):  
Frequency Conversion ◽  
Voltage Drop ◽  
Asynchronous Motor ◽  
Sine Wave ◽  
Open Loop ◽  
Loop Control ◽  
Grid Voltage ◽  
Starting Current ◽  
Soft Start ◽  
The Impact

Since over large starting current makes an instant giant grid voltage drop and contacting with current spark can damage the starting device when three phase asynchronous motor is directly started, in order to reduce the impact on the grid and the motor caused by the over large starting current, the present disclosure provides a frequency conversion soft start system based on SPWN. Control system generates IGBT controlled by SPWM pulse control using the regular sampling II method, thus achieving an AC infinitely approaching to a sine wave to open-loop control the motor and implement soft start. The method of frequency conversion soft start based on SPWM may implement a smooth start of the motor with lesser starting current and larger starting torque, thereby largely reducing the impact on the grid voltage and the motor. The experimental results showed that the method of frequency conversion soft start based on SPWM effectively reduces the starting current and implements the motor’s smooth start.

scholarly journals A Novel Vector Control of Five-phase PMSM Based on Harmonic Current Closed Loop

2018 ◽  
Vol 232 ◽  
pp. 04015
Author(s):  
Fei Yu ◽  
Yongchao Zhou
Keyword(s):  
Vector Control ◽  
High Performance ◽  
Closed Loop ◽  
Control Method ◽  
High Reliability ◽  
Permanent Magnet Synchronous Motor ◽  
Coordinate Frame ◽  
Harmonic Current ◽  
Loop Control ◽  
Multi Phase

Multi-phase electric machines such as five-phase permanent magnet synchronous motor (PMSM) play an important role in the ships electrical propulsion because of the advantages of high performance and high reliability. The decoupled mathematic models of five-phase PMSM in dq coordinate frame are established, and the reason caused to high stator harmonic current in the multi-phase motor is analyzed based on the mathematic models. To suppress the harmonic current, a novel vector control (VC) method based on SVPWM and harmonic current closed loop control is proposed. Based on the proposed algorithm, a five-phase PMSM vector control system is established with MATLAB, the performance is simulated and analyzed. The results show that, the stator harmonic current is much little than that of the traditional control method.

scholarly journals New Sensorless Speed Control of a Hybrid Stepper Motor Based on Fuzzy Sliding Mode Observer

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4939
Author(s):  
Chunlei Wang ◽  
Dongxing Cao
Keyword(s):  
Fuzzy Logic Controller ◽  
Sliding Mode ◽  
High Reliability ◽  
Low Cost ◽  
Speed Control ◽  
Torque Ripple ◽  
Open Loop ◽  
Sliding Mode Observer ◽  
Loop Control ◽  
Fuzzy Sliding Mode

Stepper motors are widely used in industrial and consumer applications due to low-cost, high reliability, and open-loop control capability. Though open-loop features a simple structure, it bears low step resolution, high torque ripple, and low energy efficiency. To improve the performance without increasing hardware cost, a fuzzy sliding mode observer (SMO)-based new sensorless speed control structure is proposed. Unlike the conventional sensorless speed control, it does not use Park and inverse Park transformations to transform currents between a-b and d-q coordinates. Instead, it uses a new current transformation method to generate reference currents of stator windings, which not only reduces the calculation burden of the controller, but also improves the stability of the system. To reduce the chattering, a fuzzy logic controller (FLC) embedded into the SMO is designed to adjust the observer gain adaptively, without using the conventional method that replaces the discontinuous sign function with the continuous, such as sigmoid or saturation function. The effectiveness of the proposed controller is verified using MATLAB/Simulink simulation (R2018b, MathWorks, Natick, MA, USA) and experiment by assessing the speed and position tracking abilities.

Sensorless Vector Control of Induction Motor Based on Machine Model

2012 ◽  
Vol 572 ◽  
pp. 371-375 ◽  
Author(s):  
Xin Qi ◽  
Chang Song Wang ◽  
Xiang Hua Ma
Keyword(s):  
Vector Control ◽  
Induction Motor ◽  
High Reliability ◽  
Low Cost ◽  
Current Model ◽  
Open Loop ◽  
Machine Model ◽  
Speed Sensor ◽  
Sensorless Vector Control ◽  
Rotor Flux

Spatial orientation and magnitude of the rotor flux is essential for vector control of induction motor. Traditionally, current model serves for rotor flux estimation and rotor must be measured by speed sensor. Due to advantages of low cost and high reliability, control the induction motor without sensor draws great attention of scholars around the world. Closed-loop observers or open-loop estimators are used for such purpose. In this paper a new method of sensorless vector control of induction motor is proposed and simulation is implemented to verify the scheme.

Open-loop control of compensation for optical propagation through a turbulent shear flow

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen
Keyword(s):  
Shear Flow ◽  
Open Loop ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Open Loop Control ◽  
Loop Control ◽  
Optical Propagation

scholarly journals Learning from and Leveraging Multi-Level Changes in Responses to the COVID 19 Pandemic to Facilitate Breast Cancer Prevention Efforts

2021 ◽  
Vol 18 (13) ◽  
pp. 6999
Author(s):  
Deborah J. Bowen ◽  
Kelly E. Rentscher ◽  
Amy Wu ◽  
Gwen Darien ◽  
Helen Ghirmai Haile ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Health Care ◽  
Cancer Prevention ◽  
Care Delivery ◽  
Breast Cancer Prevention ◽  
Health Care Use ◽  
Economic Life ◽  
Future Research ◽  
Multi Level ◽  
And Shifts

The coronavirus pandemic (COVID-19) has had multilevel effects on non-COVID-19 health and health care, including deferral of routine cancer prevention and screening and delays in surgical and other procedures. Health and health care use has also been affected by pandemic-related loss of employer-based health insurance, food and housing disruptions, and heightened stress, sleep disruptions and social isolation. These disruptions are projected to contribute to excess non-COVID-19 deaths over the coming decades. At the same time municipalities, health systems and individuals are making changes in response to the pandemic, including modifications in the environmental to promote health, implementation of telehealth platforms, and shifts towards greater self-care and using remote platforms to maintain social connections. We used a multi-level biopsychosocial model to examine the available literature on the relationship between COVID-19-related changes and breast cancer prevention to identify current gaps in knowledge and identify potential opportunities for future research. We found that COVID-19 has impacted several aspects of social and economic life, through a variety of mechanisms, including unemployment, changes in health care delivery, changes in eating and activity, and changes in mental health. Some of these changes should be reduced, while others should be explored and enhanced.

scholarly journals Sensuator: A Hybrid Sensor–Actuator Approach to Soft Robotic Proprioception Using Recurrent Neural Networks

Actuators ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 30
Author(s):  
Pornthep Preechayasomboon ◽  
Eric Rombokas
Keyword(s):  
Neural Networks ◽  
Recurrent Neural Networks ◽  
Linear Models ◽  
Open Loop ◽  
Proof Of Concept ◽  
State Estimator ◽  
Loop Control ◽  
Practical Applications ◽  
Soft Actuator ◽  
The Cost

Soft robotic actuators are now being used in practical applications; however, they are often limited to open-loop control that relies on the inherent compliance of the actuator. Achieving human-like manipulation and grasping with soft robotic actuators requires at least some form of sensing, which often comes at the cost of complex fabrication and purposefully built sensor structures. In this paper, we utilize the actuating fluid itself as a sensing medium to achieve high-fidelity proprioception in a soft actuator. As our sensors are somewhat unstructured, their readings are difficult to interpret using linear models. We therefore present a proof of concept of a method for deriving the pose of the soft actuator using recurrent neural networks. We present the experimental setup and our learned state estimator to show that our method is viable for achieving proprioception and is also robust to common sensor failures.

Sign in / Sign up

Export Citation Format

Share Document