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Modeling and Simulation of the SRM Drive System
Published in R. Krishnan, Switched Reluctance Motor Drives, 2017
The third factor merits further attention here. Torque ripple reduction is absolutely necessary in SRM drives if they are to find applications in high-performance environments. The reduction is achieved in many ways but most of them are based on the premise that the sum of the air gap torques produced by the outgoing phase and the incoming phase has to be equal to the overall torque command. Therefore, the individual phase torque commands for the outgoing and incoming phases have to be identified for each operating point that is a function of the rotor position. In this method, the slope of the outgoing current is controlled and the radial force can be controlled to mitigate the acoustic noise. A number of advantages can accrue with this torque command modification in the torque controller. Hereafter, the output of the torque controller will be labeled as a modified torque command. The modeling of this block is then based on the three factors discussed. The first two factors are easy to incorporate: the first factor as a torque limiter with time constraints, and the second factor in the load torque as a function of rotor position and/or speed. The third factor uses one of the algorithms discussed in Chapter 5 to mitigate the ripple torque. The latter is usually a function of rotor position and sometimes also magnitude of current.
Mechatronic and Electromechanical Systems
Published in Sergey Edward Lyshevski, Mechatronics and Control of Electromechanical Systems, 2017
An electromechanical system is shown in Figure 1.5a. A pointing system kinematics, geared motor (coupled within the kinematics using the torque limiter), PWM amplifier, ICs, and DSP are shown. Using the reference r and the measured angular displacement θ, the DSP develops the PWM signals to drive high-frequency MOSFETs. The number of the PWM outputs depends on the converter topology. A three-phase permanent-magnet synchronous motor is used. Six PWM outputs drive six transistors to vary the phase voltages uas, ubs, and ucs. The magnitude of the output voltage of the PWM amplifier is controlled by changing the transistors duty cycle. The Hall-effect sensors measure the rotor angular displacement θr to generate the balanced phase voltages uas, ubs, and ucs. A fully integrated electromechanical system hardware includes actuator–mechanism coupling with a torque limiter, sensors, microelectronics, and power electronics. The operating principles and basic foundations of conventional, mini and microscale electromechanical motion devices are based on classical electromagnetics and mechanics, as depicted in Figure 1.5b.
Dependability analysis of a product line using its model
Published in Stein Haugen, Anne Barros, Coen van Gulijk, Trond Kongsvik, Jan Erik Vinnem, Safety and Reliability – Safe Societies in a Changing World, 2018
B. Chieb, V. Idasiak, F. Kratz
For example, if we analyze, the “Require” relation who is used to manage the variation of the optional elements ‘safety automaton’ and ‘sensor bis’. The impacted FMECA lines have several types (T6, T7, and T8). These elements must be optional in order to apply this relationship. The alternative choice between two elements is presented in the pre-FMECA of our case study by the relation “XOR”. For example, the presence of the element ‘elastic coupling 1’ excludes the presence of the element ‘torque limiter’ and vice versa. Indeed, the analysis is done in the case of a product configuration on a single element among the set of alternative elements. The alternative relationship is applied to optional elements.
Dynamic characteristics and friction torque design method for bogies with friction coupling independently rotating wheelsets
Published in Vehicle System Dynamics, 2022
Yuanjin Ji, Youpei Huang, Han Leng, Lihui Ren, Jinsong Zhou, Dao Gong
Currently, a new type of coupled wheelset structure with independently rotating wheelsets is available, that is, the left and right wheels are coupled through a dry friction pair. friction coupling independently rotating wheelsets have a simple structure, low cost, and easy implementation and application. Bracciali et al. proposed the concept of partially independent wheelsets (partially independently rotating wheelsets) (Fig. 1a), comparatively analysed the dynamic performance of partially independent wheelsets and the rigid wheelset, and focused on the effect of a torque limiter on rolling contact fatigue (RCF). They indicated that setting an appropriate torque limiter could effectively decrease the rail RCF damage and the formation of rail corrugation on small-radius curves [12,13]. Shi et al. proposed a new type of lateral coupling structure for independent rotating wheels (IRW) (Fig. 1b), which used the friction pair instead of the gear pair to synchronise the rotation speed of the left and right wheels, so as to obtain the longitudinal creep rate [14]. Leng Han et al. established the mechanical model of the transverse friction coupling independently rotating wheelsets (TFCW) based on the structure of the friction limited-slip differential (Fig. 1c), studied the curve performance and critical speed of the friction coupling independently rotating wheelsets, and analysed the effect of friction torque on dynamic performance [15].
Influence of gap distance between bone and plate on structural stiffness and parallel interfragmental movement in far-cortical locking technique - a biomechanical study
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Yong-Jian Feng, Kang-Ping Lin, Cheng-Lung Tsai, Hung-Wen Wei
The DDTL (A Plus Biotechnology Co., Ltd., Taiwan) screws and 12-holes locking plate (ABS Locking Plate, A Plus Biotechnology Co., Ltd., Taiwan) were utilized for mechanical validation. The locking plate is 19 mm in width, 212 mm in length, and 7 mm in thickness. All implants were made of titanium alloy (Ti-6Al-4V). Three specimens were prepared for in vitro mechanical tests using composite sawbones (Bottlang et al. 2009; 2010; Claes 2011; Doornink et al. 2011; Döbele et al. 2014). The cylinder bone surrogates with a diameter of 30 mm and a wall thickness of 7 mm (Sawbones #3403; Pacific Research Laboratories, Vashon, Washington) were cut into 110 mm in length, and then plates were fixed with three DDTL screws in both proximal and distal bone surrogates and with a 10-mm osteotomy gap to simulate a comminuted fracture pattern (Bottlang et al. 2009). Plates were fixed at 2mm elevated from the bone surface (Figure 4). The screw length was 42mm. Each screw was tightened to 4 Nm using torque limiter.
Developed an Improved Fractional Ordered Darwinian Particle Swarm Optimization Using Fuzzy Logic Controller to Improve the Performance Measures on E-Vehicle
Published in Electric Power Components and Systems, 2023
I. Andrews Juben Ratchanyaraj, R. Samson Ravindran
The inverter is based on IGBTs, the controller of the torque, and the controller of speed comprises motion with direct torque control. Applying the standard speed leads to the rotor speed, an error signal may be generated. To maintain torque under control, a torque limiter is employed. Calculating torque inaccuracy can be accomplished by relating the limited torque reference (Tref) with the torque in actual units measured by the machine, as illustrated in Table 1. Based on the predicted rotor speed flux as well as stator flux, a motor’s reference speed is calculated. Flux and torque errors determine the switching vectors for the VSI. Accordingly, the energies of the rotor and the stator determine how much torque there is: