scholarly journals Wind Micro-Turbine Networks for Urban Areas: Optimal Design and Power Scalability of Permanent Magnet Generators

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2759 ◽  
Author(s):  
Marco Palmieri ◽  
Salvatore Bozzella ◽  
Giuseppe Cascella ◽  
Marco Bronzini ◽  
Marco Torresi ◽  
...  

This work is focused on the design optimization of electrical machines that are used in small-scale direct-drive aerogenerators. A ducted wind turbine, equipped with a diffuser, is considered due to its enhanced power capability with respect to bare turbines. An annular type Permanent Magnet brushless generator is integrated in the turbine structure: the stator coils are placed in the internal part of the diffuser, whereas the permanent magnets are on an external ring connected to the turbine blade tips. Moreover, as regards the stator windings, the Printed Circuit Board (PCB) technology is investigated in order to exploit its advantages with respect to conventional wire coils, such as the increased current density capacity, the reduction of costs, and the enhanced precision and repeatability of the PCBs. An original design procedure is presented together with some scalability rules. An automated tool has been developed in order to aid the electrical machine designer in the first design stages: the tool performs multi-objective optimizations (using the Matlab Genetic Algorithm Toolbox), coupled to fast Finite Element analysis (through the open-source software FEMM) for the evaluation of the electromagnetic torque and field distribution. The proposed procedure is applied to the design of an annular PM generator directly coupled to a small-scale turbine for an urban application.

Author(s):  
J.F. Pan ◽  
Norbert Cheung

PurposeThe paper aims to discuss a new direction of design outline of four‐axis machine with multi‐dimensional motors. It proposes an integrated, direct‐drive machine based on switched reluctance (SR) principles. This includes how the machine is constructed and the structure of each axis of motion. The simulation and control results are also provided for performance prediction. The study aims to provide a solution and find applications for high‐performance, low‐cost manufacturing facilities.Design/methodology/approachThe study is based on simulation and experimental results for performance prediction of the multi‐dimensional motors. With the approach of grounded theory on SR machines, design and construction of each axis of motion is verified with finite element analysis. Then, corresponding control strategy is provided for the control of each axis of motion. Some corresponding experimental results are carried out to verify motor performance.FindingsThe paper provides a general design procedure for direct‐drive, integrated, multi‐dimensional SR motors. It suggests a mechanically robust, low‐cost and simple machine structure for potential applications of industrial multi‐axis machines.Research limitations/implicationsConsidering the performance from the prototype, it is expected to find applications in low‐level force and torque output such as automated small‐scale printed circuit board drillings.Practical implicationsOwing to the limitations of the present study, the machine needs further control tests for robust or adaptive applications. Therefore, researchers are encouraged to implement further advanced control strategies on the machine.Originality/valueThe authors attempt to provide a comprehensive solution of multi‐axis machine design based on direct‐drive, low‐cost multi‐dimensional SR motors.


Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2224 ◽  
Author(s):  
Pierpaolo Dini ◽  
Sergio Saponara

This work addresses the problem of mitigating the effects of the cogging torque in permanent magnet synchronous motors, particularly brushless motors, which is a main issue in precision electric drive applications. In this work, a method for mitigating the effects of the cogging torque is proposed, based on the use of a nonlinear automatic control technique known as feedback linearization that is ideal for underactuated dynamic systems. The aim of this work is to present an alternative to classic solutions based on the physical modification of the electrical machine to try to suppress the natural interaction between the permanent magnets and the teeth of the stator slots. Such modifications of electric machines are often expensive because they require customized procedures, while the proposed method does not require any modification of the electric drive. With respect to other algorithmic-based solutions for cogging torque reduction, the proposed control technique is scalable to different motor parameters, deterministic, and robust, and hence easy to use and verify for safety-critical applications. As an application case example, the work reports the reduction of the oscillations for the angular position control of a permanent magnet synchronous motor vs. classic PI (proportional-integrative) cascaded control. Moreover, the proposed algorithm is suitable to be implemented in low-cost embedded control units.


Author(s):  
M,M.J, Al-ani ◽  
Z.Q. Zhu

Purpose – The purpose of this paper is to investigate and compare the influence of end-effect on the torque-speed characteristics of three conventional switched flux permanent magnet (SFPM) machines having different stator/rotor pole combinations, i.e. 12/10, 12/13 and 12/14 as well as three novel topologies with less permanent magnets (PMs), i.e. multi-tooth, E-core and C-core. Design/methodology/approach – SFPM machines combine the advantages of simple and robust rotor and easy management of the temperature due to the location of the PMs and armature windings on the stator. However, due to spoke location of the PMs a large flux leakage in the end region, i.e. end-effect, can be observed which could result in a large reduction in the electromagnetic performance. Therefore, the influence of end-effect on the torque-speed characteristics is investigated. 3D-finite element analyses (FEA) results are compared with their 2D-FEA counterparts in order to account for the end-effect influence. Findings – It has been concluded that due to end flux leakage, lower torque capability in the constant torque region is observed in the six machines. However, improved flux-weakening capability in the conventional machines can be exhibited at high current levels, whereas due to the large inductance lower power capability in the multi-tooth, E-core and C-core machines is obtained. Research limitations/implications – The influence of temperature rise on the performance is not included. Originality/value – This paper has analysed the influence of end-effect on the torque-speed characteristics of several SFPM machines.


2020 ◽  
Vol 220 ◽  
pp. 01040
Author(s):  
Alfred Safin ◽  
Timur Petrov

Permanent magnet synchronous motors are increasingly used in the oil industry. These motors need to be made more energy efficient. To do this, it is necessary to optimize the rotor of a synchronous motor by changing the design through topological optimization. Designing an electrical machine as a heuristic process does not guarantee finding the best solution. Methods are needed that complement the experience and intuition of the designer to find the optimal (rational) solution. Topological optimization is currently performed using the finite element method to reduce mass and improve the stiffness of structures. The proposed method allows you to transfer topological optimization to electromagnetic processes in permanent magnet synchronous motors to determine the direction of magnetization and the size of permanent magnets, for a given mass-dimensional parameters. Optimization of the rotor of a serial permanent magnet motor based on a genetic algorithm is proposed. A new topology of the rotor of the motor was calculated and an increase in the torque was obtained by 18.2%, which indicates that topological optimization is promising for synchronous motors with permanent magnets.


2006 ◽  
Vol 128 (12) ◽  
pp. 24-27 ◽  
Author(s):  
Annette von Jouanne

This article elaborates ways of harnessing the power of the ocean. Engineers have attempted, with varying success, to tap ocean energy as it occurs in waves, tides, marine currents, thermal gradients, and differences in salinity. Among these forms, significant opportunities and benefits have been identified in the area of wave-energy extraction. As a form of harvestable energy, waves have advantages not simply over other forms of ocean power, but also over more conventional renewable energy sources, such as the wind and the sun. Wave energy also offers much higher energy densities, enabling devices to extract more power from a smaller volume at consequent lower costs. The Oregon State University (OSU) wave energy team is developing several novel direct-drive prototypes, including buoys that incorporate permanent magnet linear generators, permanent magnet rack-and-pinion generators, and contactless force transmission generators. The OSU researchers are also interested in small-scale wave-energy generators, which could be integrated into boat anchor systems to power a variety of small craft electronic devices.


Author(s):  
Marcin Wardach ◽  
Ryszard Palka ◽  
Piotr Paplicki ◽  
Michal Bonislawski

Purpose Permanent magnet (PM) electrical machines are becoming one of the most popular type of the machines used in electrical vehicle drive applications. The main drawback of permanent magnet machines, despite obvious advantages, is associated with the flux control capability, which is limited at high rotor speeds of the machine. This paper aims to present a new arrangement of permanent magnets and flux barriers in the rotor structure to improve the field weakening control of hybrid excited machines. The field weakening characteristics, back-emf waveforms and efficiency maps of this novel machine have been reported. Design/methodology/approach In the study, finite element analysis was used to perform simulation research. Then, based on the simulation studies, an experimental model was built. The paper also presents selected experimental results. Findings Obtained results show that the proposed machine topology and novel control strategy can offer an effective flux control method allowing to extend the maximal rotational speed of the machine at constant power range. Practical implications The proposed solution can be used in electric vehicles drive to extend its torque and speed range. Originality/value The paper presents original design and results of research on a new solution of a hybrid excited machine with magnetic barriers in a rotor.


Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 216 ◽  
Author(s):  
Minh-Trung Duong ◽  
Do-Hyun Kang ◽  
Yon-Do Chun ◽  
Byung-Chul Woo ◽  
Yoon-Sun Lee ◽  
...  

In this paper, finite element analysis demonstrates the difference between dual-permanent-magnet-excited machines (DPMM) and surface-mounted permanent magnet machines (SPM) in terms of tangential force at the same air gap, diameter, stacking length, and input current. Different from most conventional machines, a novel DPMM has two sets of permanent magnets employed on both stator and rotor. To make a fair comparison, the novel DPMM, based on an original design, is specified to have the same dimensions as a conventional SPM. With the aid of 2D finite element analysis, tangential force generated from the novel DPMM is 167.65% higher than the conventional SPM. To verify the validity of the analyses, a prototype was fabricated and tested. Experiments showed that average deviation was only approximately 1.85%.


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