scholarly journals Radial force cancellation of bearingless brushless direct current motor using integrated winding configuration

Author(s):  
Ali A. Yousif ◽  
Ahmed M. Mohammed ◽  
Mohammed Moanes E. Ali

A bearingless brushless direct current (BLDC) motor incorporates the function of magnetic bearings into a BLDC motor, making it a new type of high-performance motor. In this paper, the main motor windings are used to generate the radial force cancellation by injecting the required dc current, “integrated winding configuration”. The bearingless BLDC motor, direct current (DC) cancellation system model is established with the aid of (ANSYS/MAXWELL) software. The simulation results confirm that the rotor radial force is approximately zero and results from a balanced distribution of the magnetic flux density. The proposed DC excitation system is suitable to realize the rotor radial force cancellation in the bearingless BLDC motor. The simulation results of the proposed configuration show the approach of integrating winding configuration at different active pole positions to find the more efficient suspension performance and reduce the suspensions system current.

2011 ◽  
Vol 366 ◽  
pp. 444-446
Author(s):  
Peng Zhang ◽  
Bao Wei Song ◽  
Xiao Xu Du

Autonomous underwater lurk vehicle is a new type of autonomous underwater vehicle, and the advantages of autonomous underwater lurk vehicle are intelligent, long-term working, covert, high-performance and recyclables, etc. It leads great contribution to the civilian and military application. In this paper, the frames were built first. Then, based on rigid body momentum and moment of momentum theorem, the dynamics equation of autonomous underwater lurk vehicle was built. At last, the landing motion of the autonomous underwater lurk vehicle was simulated. The simulation results show preliminarily that the autonomous underwater lurk vehicle can steady complete the required landing motion.


Author(s):  
Farina Sulaiman ◽  
R.N. Firdaus ◽  
M. S. Ahmad ◽  
A. Jidin ◽  
T. Sutikno

This paper discusses about winding arrangement of fractional slot of a new type hollow rotor Brushless Direct Current (BLDC) motor. Hollow rotor has higher performance compared to other BLDC motor because it minimizes the unused flux below permanent magnet and maximize torque produce by the motor. It’s also known that 8 pole motor is favorite used in industrial because it has an optimum space of permanent magnet for a smaller motor size. The number of pole will affect the maximum speed of the rotor. Thus, the objective of this research is to investigate the best winding arrangement for 8 pole of hollow rotor that could produce the highest electromagnetic performance. At starts, four combinations of slot number and coil sizes had been selected. Structural comparison in term of coil vector and winding arrangement is studied. Finite Element Method (FEM) had been used to simulate the parameters such as backemf and torque waveforms. It was convinced that 9 slot 8 pole with 0.6 size of coil produces the best performance. The confirmed model had been fabricated and measured. Both results from FEM and measurement are compared in term of backemf and torque where percentage differences are 7.4 % and 8 %, respectively. As conclusion, this research shows the fundamental of winding arrangement of fractional slot of motor especially 8 pole motor.


2020 ◽  
Vol 38 (8A) ◽  
pp. 1187-1199
Author(s):  
Qaed M. Ali ◽  
Mohammed M. Ezzalden

BLDC motors are characterized by electronic commutation, which is performed by using an electric three-phase inverter. The direct control system of the BLDC motor consists of double loops; including the inner-loop for current regulating and outer-loop for speed control. The operation of the current controller requires feedback of motor currents; the conventional current controller uses two current sensors on the ac side of the inverter to measure the currents of two phases, while the third current would be accordingly calculated. These two sensors should have the same characteristics, to achieve balanced current measurements. It should be noted that the sensitivity of these sensors changes with time. In the case of one sensor fails, both of them must be replaced. To overcome this problem, it is preferable to use one sensor instead of two. The proposed control system is based on a deadbeat predictive controller, which is used to regulate the DC current of the BLDC motor. Such a controller can be considered as digital controller mode, which has fast response, high precision and can be easily implemented with microprocessor. The proposed control system has been simulated using Matlab software, and the system is tested at a different operating condition such as low speed and high speed.


2021 ◽  
Vol 2 (1) ◽  
pp. 46-62
Author(s):  
Santiago Iglesias-Baniela ◽  
Juan Vinagre-Ríos ◽  
José M. Pérez-Canosa

It is a well-known fact that the 1989 Exxon Valdez disaster caused the escort towing of laden tankers in many coastal areas of the world to become compulsory. In order to implement a new type of escort towing, specially designed to be employed in very adverse weather conditions, considerable changes in the hull form of escort tugs had to be made to improve their stability and performance. Since traditional winch and ropes technologies were only effective in calm waters, tugs had to be fitted with new devices. These improvements allowed the remodeled tugs to counterbalance the strong forces generated by the maneuvers in open waters. The aim of this paper is to perform a comprehensive literature review of the new high-performance automatic dynamic winches. Furthermore, a thorough analysis of the best available technologies regarding towline, essential to properly exploit the new winches, will be carried out. Through this review, the way in which the escort towing industry has faced this technological challenge is shown.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2715
Author(s):  
Ruth Yadira Vidana Morales ◽  
Susana Ortega Cisneros ◽  
Jose Rodrigo Camacho Perez ◽  
Federico Sandoval Ibarra ◽  
Ricardo Casas Carrillo

This work illustrates the analysis of Film Bulk Acoustic Resonators (FBAR) using 3D Finite Element (FEM) simulations with the software OnScale in order to predict and improve resonator performance and quality before manufacturing. This kind of analysis minimizes manufacturing cycles by reducing design time with 3D simulations running on High-Performance Computing (HPC) cloud services. It also enables the identification of manufacturing effects on device performance. The simulation results are compared and validated with a manufactured FBAR device, previously reported, to further highlight the usefulness and advantages of the 3D simulations-based design process. In the 3D simulation results, some analysis challenges, like boundary condition definitions, mesh tuning, loss source tracing, and device quality estimations, were studied. Hence, it is possible to highlight that modern FEM solvers, like OnScale enable unprecedented FBAR analysis and design optimization.


Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 288
Author(s):  
Adam Wolniakowski ◽  
Charalampos Valsamos ◽  
Kanstantsin Miatliuk ◽  
Vassilis Moulianitis ◽  
Nikos Aspragathos

The determination of the optimal position of a robotic task within a manipulator’s workspace is crucial for the manipulator to achieve high performance regarding selected aspects of its operation. In this paper, a method for determining the optimal task placement for a serial manipulator is presented, so that the required joint torques are minimized. The task considered comprises the exercise of a given force in a given direction along a 3D path followed by the end effector. Given that many such tasks are usually conducted by human workers and as such the utilized trajectories are quite complex to model, a Human Robot Interaction (HRI) approach was chosen to define the task, where the robot is taught the task trajectory by a human operator. Furthermore, the presented method considers the singular free paths of the manipulator’s end-effector motion in the configuration space. Simulation results are utilized to set up a physical execution of the task in the optimal derived position within a UR-3 manipulator’s workspace. For reference the task is also placed at an arbitrary “bad” location in order to validate the simulation results. Experimental results verify that the positioning of the task at the optimal location derived by the presented method allows for the task execution with minimum joint torques as opposed to the arbitrary position.


2012 ◽  
Vol 542-543 ◽  
pp. 769-774
Author(s):  
Qun Ling Yu ◽  
Na Bai ◽  
Yan Zhou ◽  
Rui Xing Li ◽  
Jun Ning Chen ◽  
...  

A new technique for reducing the offset of latch-type sense amplifier has been proposed and effect of enable signal voltage upon latch-type sense amplifier offset in SRAM has been investigated in this paper. Circuit simulation results on both StrongARM and Double-tail topologies show that the standard deviation of offset can be reduced by 31.23% (StrongARM SA) and 25.2% (Double-tail SA) , respectively, when the voltage of enable signal reaches 0.6V in TSMC 65nm CMOS technology. For a column of bit-cell (1024 bit-cell), the total speed is improved by 14.98% (StrongARAM SA) and 22.26% (Double-tail SA) at the optimal operation point separately, and the total energy dissipation is reduced by 30.45% and 29.47% with this scheme.


Author(s):  
Ceng He ◽  
Yuqi Wang ◽  
Jing Song ◽  
Shanshan Li ◽  
Fusheng Yang ◽  
...  

Abstract Metal hydride is an influential and promising material for hydrogen utilization. Researchers have carried out a large number of studies on hydrogen storage apparatus, and developed a few new devices for its promotion. Unfortunately, for most metal hydride reactors, the hydrogenation and dehydrogenation are two independent processes owing to the different required conditions, which could cause many inconveniences and safety problems to the H2 absorption & desorption cycle with high frequency and intensity. Hence we proposed a new type of autoswitch H2 absorption & desorption device based on the structure improvement, which consists of rotation disc, fixed disc and the reactor. The numerical simulation for H2 absorption/desorption using LaNi5 was accomplished, and the optimizations on both structure and operation conditions were achieved within a certain period of cycle time. Simulation results show when the single cycle time is set to 1600 s, the absorption temperature has to be lower than 45 °C (3 MPa) and pressure higher than 1.28 MPa (20 °C), and the desorption temperature should be higher than 41 °C (0.1 MPa) and pressure lower than 0.48 MPa (80 °C) under the same cycle time. Meanwhile, the effects of reaction finish time, operating temperature and H2 pressure during absorption/desorption process was investigated and simulation data were also fitted to develop the structural optimization. Under the hydrogenation/dehydrogenation conditions of 3 MPa (20 °C)/0.1 MPa (80 °C), the simulation results indicate the optimal initial reacted fraction and total cycle time are 0.07 and 1287 s, respectively. Moreover, both structures of autoswitch device with 4 and 6 openings have been optimized to satisfy the requirement of each stage. The autoswitch H2 absorption & desorption device can realize the automatic switch between hydrogenation and dehydrogenation orderly and controllably, which would provide convenience for the occasions with this demand and show its remarkable value during popularization and application.


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