131,434 research outputs found
Estudo da interferência eletromagnética gerada por redes PLC (power line communication) no interior de edificações
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica.Os níveis de Interferência Eletromagnética (EMI) gerada por uma rede PLC, devido ao número limitado de testes já efetuados, ainda são pouco conhecidos no Brasil. Basicamente, o tema pode ser dividido em duas partes: A interferência provocada pela rede PLC em outros sistemas que compartilham o mesmo ambiente operacional e aquela provocada por outros sistemas licenciados causando distúrbios na operação de um sistema PLC. O primeiro caso se relaciona diretamente ao nível dos sinais interferentes que o organismo de regulação determinará como limite para operação dos sistemas PLC e o segundo caso se refere à redução do espectro disponível para a PLC causado pela interferência gerada por outros sistemas, implicando em taxas de transmissão muito baixas, e inviabilizando assim sua implantação. Considerando o provável público-alvo dessa aplicação, a implantação da PLC se viabilizará em locais de grande concentração urbana onde já existem outros sistemas operando na mesma faixa de frequência. Portanto, o prévio conhecimento do comportamento de uma rede PLC se revela de extrema importância para o sucesso da tecnologia. Diante disto, o objetivo principal deste trabalho é fornecer subsídios técnicos que comprovem a aplicabilidade da PLC em áreas internas a edificações, também conhecida como aplicações indoor da tecnologia Power Line Communication
Development and testing aspects of high speed induction machines
No full textThis paper reviews the development and testing aspects of high speed induction machines, through a case study involving a 120 [kW], 25000 [rpm] Induction Machine for a power generation application. In the first part, developments in materials and components including electrical steels and copper alloys are discussed, and their impact on the machines' design and construction is investigated. In the second part of this paper, the testing aspects and test results of the prototyped Induction Machines are reported
High speed solid rotor induction machine: Analysis and performances
No full textThe paper presents the design, analysis and testing aspects of high speed induction machines equipped with solid rotor. At first the theoretical background and design aspects of solid rotor for induction machines is presented considering electromagnetic, thermal and mechanical aspects and focusing on the assessment of end-region factor effects. The techniques are benchmarked against a 120 kW solid rotor induction motor designed for power generation application
A Holistic Electrical Machine Design Tool for More-Electric and Hybrid-Electric Aircraft
No full textThe power density of electrical machines required for more-electric and hybrid-electric aircraft has become a critical aspect and target of optimization. This paper looks at the development aspects of a multi-domain tool to aid for system-level optimization of electrical machines within next-generation high power-density aerospace applications. The electromagnetic, thermal and mechanical aspects are wholly integrated, thus enabling the optimization including the non-active mass. The implementation and overall architecture are described with the aim of investigating the impact of coolant flowrate, coolant medium as well as efficiency on the achievable power to mass ratio
A high-speed permanent-magnet machine for fault-tolerant drivetrains
No full textThis paper details the design considerations of a permanent magnet (PM), three phase, high speed, synchronous machine for fault tolerant operation. A multidisciplinary approach to the optimal design of the machine is adopted targeted at minimising the additional losses resulting from faulty operating conditions and accounting for the remedial control strategy implemented. The design of a closed slot, 6 slots, 4 pole machine is presented. The machine is prototyped and tested to validate the analytical-computational performances predicted in the design and analysis stage under healthy and faulty condition
Radial force control for triple three-phase sectored SPM machines. Part I: Machine model
No full textThe radial force control technique for a triple three-phase Surface Permanent Magnet (SPM) machine is investigated in this paper. The machine has a nine-phase winding arranged in three sectors and supplied by three different Voltage Source Inverters (VSI). A machine model is developed, based on the multi space vector approach. The multi space vector current control technique is exploited to control the torque and the radial force. The radial force control can be useful to compensate for a bearing fault or for a rotor eccentricity. Finite element simulations are used to validate the model and the control technique. Finally, criticalities of the control and modelling aspects are discussed
Radial force control for triple three-phase sectored SPM machines. Part II: Open winding fault tolerant control
No full textA new advanced fault tolerant control technique for a triple three-phase Surface Permanent Magnet (SPM) machine is investigated in this paper. The machine has a nine-phase winding arranged in three sectors and supplied by three different Voltage Source Inverters (VSIs). The proposed current control technique is firstly exploited to avoid the radial force appearance in case of open winding of one machine sector. Then, the radial force fault tolerant control is improved to compensate for a bearing fault or another source of radial force in this open winding condition. Finite element simulations are used to validate the two proposed control techniques. Finally, advantages and drawbacks of the solution are highlighted
Design and control of segmented triple three-phase SPM machines for fault tolerant drives
No full textA new multiphase Surface Permanent Magnet (SPM) machine design is investigated in this paper. The machine has a nine-phase winding arranged in three sectors and supplied by three different Voltage Source Inverters (VSI). Stator segmentation between these sectors is analyzed to improve the machine performance and fault tolerant behaviour. A new adaptable control technique is developed for the different segmentation geometries. Finite element simulations are used in order to validate the model and analyse possible layouts. Finally, an optimized design is proposed and the criticalities of the segmentation solution are explained
Advancements in Control, Design, and Parameter Identification of Permanent Magnet Synchronous Machines
No full textIn this work, advancements in control, design, and parameter identification of permanent magnet synchronous machines (PMSMs) are presented. These advancements take up opportunities and challenges offered by novel applications and technologies. In fact, PMSMs are increasingly adopted thanks to high efficiency and versatility, covering a wide range of applications. In particular, the use of PMSMs in the industry of small-scale wind turbines is becoming dominant. In this application, direct drive topologies coupled with variable speed and fixed pitch wind turbines are a promising solution because of their simplicity, efficiency, and reliability. In fact, this solution avoids the use of gearboxes and mechanical systems for the control of the pitch angle, reducing losses, costs, and failure risks. In this architecture, the aerodynamic power regulation is entirely entrusted to the control of the permanent magnet synchronous generator (PMSG). While several methods have been developed to achieve the maximum power point tracking, poor effort has been made to regulate the power for wind speeds above the rated one. In this work, this challenge
has been addressed by proposing an innovative control scheme in which an aerodynamic torque observer and a wind speed estimator are involved. The aim of the designed solution is to achieve the maximum power point tracking for wind speeds below the rated one and to extend the power generation in the high wind speed region. In this region, the respect of the safety mechanical limits of the system is the crucial issue. The proposed control scheme has been tested on an experimental setup in the laboratory of Electrical Machines and Drives of the Politecnico di Bari. The achieved results show that the reference power regulation characteristic has been tracked with a good accuracy covering the whole wind speed range of the system. In the context of the design of PMSMs, novel modular topologies are gaining increasing interest, especially in applications where large machines are employed. Thanks to this technology, several advantages in the manufacturing, transporting, and assembling over conventional PMSMs can be achieved. A drawback of PMSMs with modular stators is the presence of additional harmonic
components of the cogging torque, with higher amplitudes and lower frequencies than the ones of PMSMs with a one-piece stator. The minimization of these harmonics is essential to increase the control accuracy and reduce undesired noise and vibrations. Despite several methods have been developed for the cogging torque minimization, these mostly deal with conventional PMSMs. In this work, two novel methods to minimize the cogging torque of modular PMSMs are proposed and compared. Both analytical studies and heuristic procedures are adopted to solve the problem. Simulation results with the finite element method have been presented to validate the proposed methods. The results achieved exhibit a reduction of the cogging torque over 90% and show that conventional methods used for one-piece stator PMSMs are not effective against the additional harmonic components produced by modular stators. Also, the spread of the IoTs (Internet-of-Things), edge and cloud computing
technologies offers novel perspectives on the monitoring and maintenance of PMSMs. Although data-driven approaches can be considered dominant in this context thanks to the availability of big data, the potential of model-based approaches has not been considered and exploited in this novel scenario. Modelbased approaches are based on the parameter identification of the system. Many well-known solutions have been developed to identify the parameters of PMSMs, but these are not feasible in large-scale applications because these are not designed for straight-through processing where the human component is negligible and IoTs and edge-cloud computing can give their best. Therefore, in the present work, the problem of the automated parameter identification processing data produced by the PMSM drive without ad-hoc tests or control actions is considered. This problem has been addressed by means of the design of an innovative algorithm based on coupled Adaline Neural Networks. Data
produced by the PMSM during its ordinary operations are used to feed the Adaline Neural Networks. Moreover, an analytical study has been performed for the convergence and estimation errors analysis of the proposed algorithm. Finally, simulation and experimental investigations have been performed for verification purposes. The results achieved show a good accuracy of the parameter identification, with experimental estimation errors lower than 15% without any manual action
Multi-domain optimization of high power-density PM electrical machines for system architecture selection
No full textThe power density of electrical machines for transport applications has become a critical aspect and target of optimization. This paper looks at the development of an intelligent, rapid, flexible, and multidomain tool to aid for system-level optimization of electrical machines within next-generation high power density applications. The electromagnetic, thermal, and mechanical aspects are wholly integrated, thus enabling the optimization including the nonactive mass. The implementation and overall architecture of the tool are described, and using a case study drawn fromthe aerospace industry, the tool is used to compare the power density of various surface permanentmagnet topologies including single airgap and dual airgapmachines, highlighting the particular suitability of the dual rotor topology in achieving the best power to mass ratio. Finally, the accuracy of the tool is highlighted by practical realization and experimental validation
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