20 research outputs found
Asymmetry of acetylcholinesterase and acetylcholine receptor in intact secretory vesicles from adrenal medulla
No full textSpeed Sensorless Control for a Six-Phase Induction Machine Based on a Sliding Mode Observer
No full textThis paper presents the application of a sliding mode observer for speed sensorless control of a six-phase induction machine. The use of nonlinear sliding mode techniques yields acceptable performance for both low- and high-speed motor operations over a wide speed range. The effectiveness and accuracy of the developed sensorless scheme are verified by experimental results, which demonstrate the system’s performance under various operating conditions. These results demonstrate the advantages of the proposal as a valid alternative to the conventional method, which uses a mechanical speed sensor for multiphase machines. Additionally, the sensorless approach can also serve as a redundant backup in the event of mechanical sensor failure, thereby increasing the reliability of the overall drive system
Comparison of the Effects on Stator Currents Between Continuous Model and Discrete Model of the Three-phase Induction Motor in the Presence of Electrical Parameter Variations
No full textAlgorithm for Implementation of Optimal Vector Combinations in Model Predictive Current Control of Six-Phase Induction Machines
No full textThe development of new control techniques for multiphase induction machines (IMs) has become a point of great interest to exploit the advantages of these machines compared to three-phase topology, for example, the reduced phase currents and lower harmonic contents. One of the most analyzed techniques is the model-based predictive current control (MPC) with a finite control set. This technique presents high x–y currents because of the application of one switching state throughout the whole sampling period. Nevertheless, it is one of the most used due to its excellent dynamic response. To overcome the aforementioned drawbacks, new techniques called virtual vectors have been developed, but although there are several articles with experimental results, the algorithm for implementing the technique has not been appropriately described. This document provides a clear and detailed explanation for algorithm implementation of virtual vectors through two proposed variants VV4 and VV11, in a six-phase machine drive. The first entails lower computational cost and the second lower loss in the x–y plane. According to performance indicators such as the total harmonic distortion and the mean square error for both case studies, experimental tests were evaluated to determine the implementation’s behaviour
Winding Design and Efficiency Analysis of a Nine-Phase Induction Machine from a Three-Phase Induction Machine
No full textMultiphase machines are a hot research topic in control theory and industrial applications such as electric cars. However, the availability to buy them in the market is limited or null. For this reason, it is common to rewind it from a three-phase commercial machine. In this context, the aim of this paper is two-fold. First, to introduce a straightforward procedure to rewind a nine-phase induction machine from a three-phase one. For that purpose, a study of the three-phase induction motor was performed, which included selecting a new winding design, calculating stator coils, and simulating tests with ANSYS Maxwell software to validate the design. Secondly, a performance analysis comparing the power losses through experimental tests performed to obtain the electrical parameters of both nine-phase and three-phase topologies is presented
Stakeholder perspectives on the development of a virtual clinic for diabetes care : qualitative study
No full textBackground: The development of the Internet has created new opportunities for health care provision, including its use as a
tool to aid the self-management of chronic conditions. We studied stakeholder reactions to an Internet-based “virtual clinic,”
which would allow people with diabetes to communicate with their health care providers, find information about their condition,
and share information and support with other users.
Objective: The aim of the study was to present the results of a detailed consultation with a variety of stakeholder groups in
order to identify what they regard as the desirable, important, and feasible characteristics of an Internet-based intervention to aid
diabetes self-management.
Methods: Three focus groups were conducted with 12 people with type 1 diabetes who used insulin pumps. Participants were
recruited through a local diabetes clinic. One-on-one interviews were conducted with 5 health care professionals from the same
clinic (2 doctors, 2 nurses, 1 dietitian) and with 1 representative of an insulin pump company. We gathered patient consensus via
email on the important and useful features of Internet-based systems used for other chronic conditions (asthma, epilepsy, myalgic
encephalopathy, mental health problems). A workshop to gather expert consensus on the use of information technology to improve
the care of young people with diabetes was organized.
Results: Stakeholder groups identified the following important characteristics of an Internet-based virtual clinic: being grounded
on personal needs rather than only providing general information; having the facility to communicate with, and learn from, peers;
providing information on the latest developments and news in diabetes; being quick and easy to use. This paper discusses these
characteristics in light of a review of the relevant literature. The development of a virtual clinic for diabetes that embodies these
principles, and that is based on self-efficacy theory, is described.
Conclusions: Involvement of stakeholders is vital early in the development of a complex intervention. Stakeholders have clear
and relevant views on what a virtual clinic system should provide, and these views can be captured and synthesized with relative
ease. This work has led to the design of a system that is able to meet user needs and is currently being evaluated in a pilot study
Speed Control of a Six-Phase IM Fed by a Multi-Modular Matrix Converter Using an Inner PTC With Reduced Computational Burden
No full textA variable-speed predictive torque control (PTC) of a six-phase induction machine (SPIM) fed by a multi-modular matrix converter (M-MMC) is presented in this paper. This new system inherits the advantages of both multiphase machines (i.e., inherent fault-tolerance and better distribution of the power/current per phase compared to three-phase machines) and the M-MMC (i.e., smaller size and weight, and has no bulky storage elements). In addition, with the M-MMC topology, it is possible to use two power generation sources of different characteristics instead of a single three-phase source. This article proposes a method that reduces the number of calculations significantly compared to conventional PTC to overcome this issue. Simulation and experimental results are provided for speed control, module failure performance and tolerance to the variation of the magnetization inductance of the SPIM. An experimental test bench on a customized SiC-Mosfets based M-MMC and a 5.5 kW symmetrical SPIM has been used
Identification of magnetization inductance for six-phase induction machines driven by modulated predictive control in field weakening zone
No full textFinite-control-set model predictive control (FCS-MPC) has achieved superiority in managing
multiphase induction machines due to its quick dynamic response, control flexibility, and overall good
performance. Its advantages, including simplicity, computational efficiency, compensation for system
perturbations, and effective handling of multivariable problems, have made it a competitive alternative in
various industrial applications. Nevertheless, FCS-MPC has some limitations. It is highly dependent on the
accuracy of the predictive model’s parameters. Unfortunately, the estimation of magnetizing inductance, the
most critical factor, especially in the weakening field region, has not been studied yet. Focusing on this
gap, this article proposes a technique to estimate the magnetizing inductance in the field weakening zone
for a six-phase asymmetrical induction machine driven by the FCS-MPC. Experimental tests have verified
the effectiveness of the proposed method, considering stator currents and rotor speed tracking, as well as a
reduction in the (x − y) currents.Xunta de Galicia | Ref. ED431B 2023/12,Agencia Estatal de Investigación | Ref. PID2022-136908OB-I0
Identification of magnetization inductance for six-phase induction machines driven by modulated predictive control in field weakening zone
No full textCorresponding author: Magno Ayala ([email protected])Society Section: IEEE Power & Energy Society SectionFinite-control-set model predictive control (FCS-MPC) has achieved superiority in managing multiphase induction machines due to its quick dynamic response, control flexibility, and overall good performance. Its advantages, including simplicity, computational efficiency, compensation for system perturbations, and effective handling of multivariable problems, have made it a competitive alternative in various industrial applications. Nevertheless, FCS-MPC has some limitations. It is highly dependent on the accuracy of the predictive model’s parameters. Unfortunately, the estimation of magnetizing inductance, the most critical factor, especially in the weakening field region, has not been studied yet. Focusing on this gap, this article proposes a technique to estimate the magnetizing inductance in the field weakening zone for a six-phase asymmetrical induction machine driven by the FCS-MPC. Experimental tests have verified the effectiveness of the proposed method, considering stator currents and rotor speed tracking, as well as a reduction in the ( x−y ) currents.Consejo Nacional de Ciencia y TecnologíaPrograma Paraguayo para el Desarrollo de la Ciencia y Tecnología. Proyectos de investigación y desarroll
Speed control of a six-phase IM fed by a multi-modular matrix converter using an inner PTC with reduced computational burden
No full textCorresponding author: Edgar Maqueda, ([email protected])A variable-speed predictive torque control (PTC) of a six-phase induction machine (SPIM) fed by a multi-modular matrix converter (M-MMC) is presented in this paper. This new system inherits the advantages of both multiphase machines (i.e., inherent fault-tolerance and better distribution of the power/current per phase compared to three-phase machines) and the M-MMC (i.e., smaller size and weight, and has no bulky storage elements). In addition, with the M-MMC topology, it is possible to use two power generation sources of different characteristics instead of a single three-phase source. This article proposes a method that reduces the number of calculations significantly compared to conventional PTC to overcome this issue. Simulation and experimental results are provided for speed control, module failure performance and tolerance to the variation of the magnetization inductance of the SPIM. An experimental test bench on a customized SiC-Mosfets based M-MMC and a 5.5 kW symmetrical SPIM has been used.Consejo Nacional de Ciencia y TecnologíaPrograma Paraguayo para el Desarrollo de la Ciencia y Tecnología. Incentivos para la formación de investigadores en postgrados nacionale
