505 research outputs found
Influence of skew and cross-coupling on flux-weakening performance of permanent-magnet brushless AC machines
A method is proposed for predicting the flux-weakening performance of permanent-magnet (PM) brushless ac machines accounting for skew and d-q axis cross-coupling. The method is based on a d-q-axis flux-linkage model, a hybrid 2-D finite-element (FE)-analytical method being used to predict the d- and q-axis inductances. However, it only requires 2-D FE analysis of the magnetic field distribution over a cross section of the machine. The developed method is used to predict the torque-speed characteristic of an interior PM brushless ac machine with one stator slot-pitch skew. This is compared with predictions from a direct FE analysis of the machine and validated by measurements
An Advanced Model Predictive Current Control of Synchronous Reluctance Motors
Synchronous reluctance motors (SynRMs) have, in recent years, attracted much
attention due to their high-efficiency output and nature of their construction denoted by
the lack of expensive magnetic materials, thus cheapening the overall cost whilst
increasing in robustness. These benefits have made the SynRM a strong contender
against other established electric motors in the market. Similarly, model predictive
current control (MPCC) has recently become a powerful advanced control technology in
industrial drives, being, therefore, a suitable choice for SynRM drives granting overall
high control performance and efficiency. However, current prediction in MPCC requires
a high number of voltage vectors (VVs) synthesizable by the converter, being therefore
computationally demanding.
Accordingly, the main goal of this work is the development and analysis of a more
efficient and advanced MPCC for SynRMs whilst reducing the computational burden and
delivering good control performance in contrast with the standard MPCC. Therefore, to
achieve the intended levels of efficiency and control performance in SynRM drives, a
combination of two control strategies is developed, which combines hysteresis current
control (HCC) and MPCC, dubbed in this work HCC-MPCC. Furthermore, the SynRM
dynamic model equations comprising the magnetic saturating effects and iron losses are
presented through a detailed theoretical and computational analysis of the drive’s
control. Conclusively, the developed HCC-MPCC for SynRM drives is analyzed through
thorough and rigorous experimental tests alongside the standard MPCC, whose obtained
results are detailed comprehensively.Os motores sÃncronos de relutância (SynRMs) têm, nos últimos anos, atraÃdo muita
atenção devido à s suas caracterÃsticas construtivas, designadamente pela falta de
materiais magnéticos caros, depreciando assim o custo em geral; e simultaneamente pelo
aumento em robustez. Esses benefÃcios tornaram o SynRM num forte concorrente face a
outros motores elétricos existentes no mercado. Da mesma forma, o modelo preditivo de
controlo de corrente (MPCC) tornou-se recentemente numa poderosa estratégia de
controlo avançado em acionamentos industriais, sendo, portanto, uma escolha adequada
para acionamentos envolvendo SynRMs, garantindo elevado desempenho e eficiência de
controlo. No entanto, a previsão da corrente no MPCC requer um grande número de
vetores de tensão (VVs) sintetizáveis pelo conversor, sendo, portanto, exigente
computacionalmente.
Consequentemente, o objetivo principal deste trabalho é o desenvolvimento e análise de
um MPCC mais eficiente e avançado para SynRMs, reduzindo a carga computacional e,
simultaneamente, demonstrando um bom desempenho de controlo em contraste com o
MPCC clássico. Portanto, para atingir os nÃveis pretendidos de eficiência e desempenho
de controlo em acionamentos com SynRMs, uma combinação de duas estratégias de
controlo é desenvolvida, combinando o controlo de corrente de histerese (HCC) e MPCC,
denominado neste trabalho HCC-MPCC. Além disso, as equações do modelo dinâmico
do SynRM, compreendendo os efeitos de saturação magnética e as perdas de ferro, são
apresentadas através de uma análise teórica e computacional detalhada do controlo do
acionamento. Conclusivamente, o HCC-MPCC desenvolvido para acionamentos com
SynRMs é analisado por meio de testes experimentais conjuntamente com o MPCC
padrão, sendo os resultados obtidos detalhados de forma abrangente
Predictive Stator Flux and Load Angle Control of Synchronous Reluctance Motor Drives Operating in a Wide Speed Range
This paper presents a new simplified finitecontrol-
set model predictive control strategy for synchronous
reluctance motors operating in the entire speed
range. It is a predictive control scheme that regulates the
stator flux and the load angle of the synchronous reluctance
motor, incorporating the ability to operate the drive in the
field-weakening region and respecting the motor voltage
and current limits as well as the load angle limitation
needed to operate this type of motor in the maximum
torque per voltage region. The proposed control strategy
possesses some attractive features, such as no need for
controller calibration, no weighting factors in the cost function,
good robustness against parameter mismatch, and
smaller computational cost compared to more traditional
finite-control-set model predictive control algorithms.
Simulation and experimental results obtained using a
high-efficiency synchronous reluctance motor demonstrate
the effectiveness of the proposed control scheme.info:eu-repo/semantics/publishedVersio
Model Based, Direct Flux Vector Control of Permanent Magnet Synchronous Motor Drives
This paper proposes a direct flux vector control strategy with no need for regulators tuning, suitable for permanent-magnet (PM) synchronous machine drives. The controller operates in stator flux coordinates and calculates the inverter reference voltages in a model-based fashion, taking advantage of a novel equation for the explicit evaluation of the torque angle error. The inverter current and voltage limits are exploited in a parameter-independent way. The method segregates the machine parameters into a single block, to make it very easy to switch from one machine to another. Experimental results are reported for a PM-assisted synchronous reluctance motor drive example, characterized by significant saturation and cross-saturation. State-of-the-art control techniques such as current vector control and non-model-based direct flux vector control are also considered, for the sake of comparison, in simulations and experiments
Field weakening and sensorless control solutions for synchronous machines applied to electric vehicles.
184 p.La polución es uno de los mayores problemas en los paÃses industrializados. Por ello, la electrificación del transporte por carretera está en pleno auge, favoreciendo la investigación y el desarrollo industrial. El desarrollo de sistemas de propulsión eficientes, fiables, compactos y económicos juega un papel fundamental para la introducción del vehÃculo eléctrico en el mercado.Las máquinas sÃncronas de imanes permanentes son, a dÃa de hoy la tecnologÃa más empleada en vehÃculos eléctricos e hÃbridos por sus caracterÃsticas. Sin embargo, al depender del uso de tierras raras, se están investigando alternativas a este tipo de máquina, tales como las máquinas de reluctancia sÃncrona asistidas por imanes. Para este tipo de máquinas sÃncronas es necesario desarrollar estrategias de control eficientes y robustas. Las desviaciones de parámetros son comunes en estas máquinas debido a la saturación magnética y a otra serie de factores, tales como tolerancias de fabricación, dependencias en función de la temperatura de operación o envejecimiento. Las técnicas de control convencionales, especialmente las estrategias de debilitamiento de campo dependen, en general, del conocimiento previo de dichos parámetros. Si no son lo suficientemente robustos, pueden producir problemas de control en las regiones de debilitamiento de campo y debilitamiento de campo profundo. En este sentido, esta tesis presenta dos nuevas estrategias de control de debilitamiento de campo hÃbridas basadas en LUTs y reguladores VCT.Por otro lado, otro requisito indispensable para la industria de la automoción es la detección de faltas y la tolerancia a fallos. En este sentido, se presenta una nueva estrategia de control sensorless basada en una estructura PLL/HFI hÃbrida que permite al vehÃculo continuar operando de forma pseudo-óptima ante roturas en el sensor de posición y velocidad de la máquina eléctrica. En esta tesis, ambas propuestas se validan experimentalmente en un sistema de propulsión real para vehÃculo eléctrico que cuenta con una máquina de reluctancia sÃncrona asistidas por imanes de 51 kW
Predictive Stator Flux and Load Angle Control of Synchronous Reluctance Motor Drives Operating in a Wide Speed Range
This paper presents a new simplified finitecontrol-
set model predictive control strategy for synchronous
reluctance motors operating in the entire speed
range. It is a predictive control scheme that regulates the
stator flux and the load angle of the synchronous reluctance
motor, incorporating the ability to operate the drive in the
field-weakening region and respecting the motor voltage
and current limits as well as the load angle limitation
needed to operate this type of motor in the maximum
torque per voltage region. The proposed control strategy
possesses some attractive features, such as no need for
controller calibration, no weighting factors in the cost function,
good robustness against parameter mismatch, and
smaller computational cost compared to more traditional
finite-control-set model predictive control algorithms.
Simulation and experimental results obtained using a
high-efficiency synchronous reluctance motor demonstrate
the effectiveness of the proposed control scheme.info:eu-repo/semantics/publishedVersio
Identification of Flux Maps at Constant Speed for Synchronous Motors
The accurate identification of flux linkages and inductances play a vital role in developing high-performance control methods for synchronous motors (SMs). In this thesis, the identification of flux maps of SMs at constant speed is done. The aim of this thesis is to achieve look-up tables of flux linkages as a function of machine currents. Simulation are performed on a 6.7-kW synchronous reluctance motor (SyRM). The current controlled SyRM, operating at constant speed, is fed with current sequences and the corresponding voltages are calculated. By using these calculated voltages, the motor flux linkages are identified and stored in the form of look-up tables. The iron losses and stator resistance variation are compensated during the identification process. Theses linkage look-up tables can be used as a benchmark for testing different saturation models of synchronous motors. From these look-up tables, the information about motor inductances can be obtained which can be used to fully exploit the motor torque and speed range by determining various control strategies such as the maximum torque per ampere (MTPA) and maximum torque per volt (MTPV)
PM-Assisted Synchronous Reluctance Machine Flux Weakening Control for EV and HEV Applications
In this manuscript, a novel robust torque control strategy for Permanent Magnet Assisted Synchronous Reluctance Machine drives applied to electric vehicles and hybrid electric vehicles is presented. Conventional control techniques can highly depend on machine electrical parameters, leading to poor regulation under electrical parameters deviations or, in more serious cases, instabilities. Additionally, machine control can be lost if field weakening is not properly controlled and, as a consequence, uncontrolled regeneration is produced. Thus, advanced control techniques are desirable to guarantee electric vehicle drive controllability in the whole speed/torque operation range and during the whole propulsion system lifetime. In order to achieve these goals, a combination of a robust second order current based Sliding Mode Control and a Look- up Table/Voltage Constraint Tracking based hybrid Field Weakening control is proposed, improving the overall control algorithm robustness under parameter deviations. The proposed strategy has been validated experimentally in a full scale automotive test bench (51 kW prototype) for being further implemented in real hybrid and electric vehicles
Sensorless Commissioning and Control of High Anisotropy Synchronous Motor Drives
L'abstract è presente nell'allegato / the abstract is in the attachmen
Advances in Rotating Electric Machines
It is difficult to imagine a modern society without rotating electric machines. Their use has been increasing not only in the traditional fields of application but also in more contemporary fields, including renewable energy conversion systems, electric aircraft, aerospace, electric vehicles, unmanned propulsion systems, robotics, etc. This has contributed to advances in the materials, design methodologies, modeling tools, and manufacturing processes of current electric machines, which are characterized by high compactness, low weight, high power density, high torque density, and high reliability. On the other hand, the growing use of electric machines and drives in more critical applications has pushed forward the research in the area of condition monitoring and fault tolerance, leading to the development of more reliable diagnostic techniques and more fault-tolerant machines. This book presents and disseminates the most recent advances related to the theory, design, modeling, application, control, and condition monitoring of all types of rotating electric machines
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