Optimisation of Low-speed Permanent-magnet Synchronous Machines with Different Rotor Designs PDF Download

Author: Petri Lampola
Publisher:
ISBN: 9789512249909
Category :
Languages : en
Pages : 28

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Tiivistelmä: Hidasnopeuksisen, kestomagnetoidun tahtikoneen erilaisten roottorirakenteiden optimointi.

Author: Matthew Gates Angle
Publisher:
ISBN:
Category :
Languages : en
Pages : 285

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Book Description
Improvement of performance of robots has necessitated technological advances in control algorithms, mechanical structures, and electric machines. Running, legged robots have presented challenges in the area of electric machinery in particular. In addition to the low-speed, high-torque, low-mass requirements on the machines, the act of running results in an unconventional drive cycle that consists of brief periods of high torque followed by long stretches of minimal torque requirement, a performance envelope that is not matched by commercially-available machines. An optimized motor would dissipate the minimum possible power over the given drive cycle, lowering temperatures and potentially reducing required battery mass or extending range. These performance requirements have motivated faster modeling techniques to enable optimization of designs for these unconventional applications. This thesis presents a novel, fast modeling method for permanent magnet synchronous machines consisting of a hybrid model comprising an explicit Maxwell solution and a Flux Tube solution. The Maxwell solution is performed for the rotor and airgap of the machine, where geometries are simple and materials are homogeneous. The stator, with its geometric complexities and non-linear materials, is modeled with a lumped-parameter model based on ux tubes. The two models are then stitched together, forced to be self-consistent with boundary conditions, and allowed to converge. This captures effects such as cogging torque as well as saturation of the core materials. The method is approximately four orders of magnitude faster than a reference finite element program (0.01 s versus 100 s) for the same accuracy. The modeling method is implemented for two topologies of surface-mount permanent-magnet machines, an internal-rotor machine and an external-rotor machine. It is then used to optimize machine design to a given drive cycle, including effects of core loss. A machine is built to demonstrate the validity of the model and optimization method and test results match predictions of instantaneous torque to within 5% at the worst point. Cogging torque is another aspect of performance that is important to machines for robotics and other applications. These pulsations in torque caused by magnet alignment with geometric features in the stator result in undesired vibrations and issues with control. One method, based on skew, for reducing or eliminating cogging torque is explored, and a simple analytical technique to predict the eect of skew is presented. Based on the machine optimized for the Cheetah, two additional machines were built to explore the effects of cogging: a skewed-rotor machine, and a skewed- stator machine. Each demonstrated reduction of a particular cogging harmonic or all of the cogging. The skewed machines reduced cogging by approximately 85%. Novel magnet shapes which further reduce cogging are presented and finite element modeling suggests that they can further reduce cogging by 60% over a straight skew. The design and optimization tools developed herein and described above were used to optimize a motor for the MIT Cheetah Robot. The resulting motor showed nearly an order of magnitude increase in torque density when compared to commercial, off-the-shelf machines (1.3 kg vs 820 g and 10 Nm vs 28 Nm) with simultaneous improvements to efficiency.

Author: Wei Xu
Publisher: CRC Press
ISBN: 1000909700
Category : Technology & Engineering
Languages : en
Pages : 279

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Book Description
Permanent magnet synchronous motors (PMSMs) are popular in the electric vehicle industry due to their high-power density, large torque-to-inertia ratio, and high reliability. This book presents an improved field-oriented control (FOC) strategy for PMSMs that utilizes optimal proportional-integral (PI) parameters to achieve robust stability, faster dynamic response, and higher efficiency in the flux-weakening region. The book covers the combined design of a PI current regulator and varying switching frequency pulse-width modulation (PWM), along with an improved linear model predictive control (MPC) strategy. Researchers and graduate students in electrical engineering, systems and control, and electric vehicles will find this book useful. Features: • Implements evolutionary optimization algorithms to improve PMSM performance. • Provides coverage of PMSM control design in the flux-weakening region. • Proposes a modern method of model predictive control to improve the dynamic performance of interior PMSM. • Studies the dynamic performance of two kinds of PMSMs: surface-mounted and interior permanent magnet types. • Includes several case studies and illustrative examples with MATLAB®. This book is aimed at researchers, graduate students, and libraries in electrical engineering with specialization in systems and control and electric vehicles.

Author: Sadegh Vaez-Zadeh
Publisher: Oxford University Press
ISBN: 0191060674
Category : Technology & Engineering
Languages : en
Pages : 384

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Book Description
Permanent magnet synchronous (PMS) motors stand at the forefront of electric motor development due to their energy saving capabilities and performance potential. The motors have been developed in response to mounting environmental crises and growing electricity prices, and they have enabled the emergence of motor drive applications like those found in electric and hybrid vehicles, fly by wire, and drones. Control of Permanent Magnet Synchronous Motors is a timely advancement along that path as the first comprehensive, self-contained, and thoroughly up-to-date book devoted solely to the control of PMS motors. It offers a deep and extended analysis, design, implementation, and performance evaluation of major motor control methods, including Vector, Direct Torque, Predictive, Deadbeat, and Combined Control, in a systematic and coherent manner. All major Sensorless Control and Parameter Estimation methods are also studied. The book places great emphasis on energy saving control schemes.

Author: Nicola Bianchi
Publisher: IET
ISBN: 1839532637
Category : Science
Languages : en
Pages : 368

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The comprehensive reference on synchronous reluctance machines, which offer high power density at low cost and support the electrification in the transport sector. This book, written by top academic and industry experts, covers all topics required to design these machines.

Author: Mousalreza Faramarzi Palangar
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Future energy concerns and global economic challenges are encouraging the world to undertake energy conservation projects. A significant way to address these concerns is to increase the energy efficiency of electric appliances. Since electric machines account for roughly 45% of all industrial electricity usage, an immense amount of energy saving can be accomplished by increasing the efficiency of electric motors. Induction motors are used in industry because of advantages like self-starting capability, affordable manufacturing cost and maintenance. However, intrinsic drawbacks of induction motors like comparatively low efficiency and power factor are not easy to overcome, even though induction motor performance has improved dramatically over the years. -- Manufacturers of electric motors worldwide are gradually focusing on alternative electric machine technology to meet more rigorous energy efficiency requirements. Hence, line-start permanent magnet synchronous motor (LSPMSM) machinery has gained substantial recognition in comparison with other motor types. This type of motor has been made very appealing by significant benefits like self-starting, high efficiency and power factor. Extensive literature research on LSPMSMs has been undertaken, concentrating primarily on the development of rotor configurations, developing the steady-state analytical model, and using the transient time-step finite element (FE) approach for synchronization evaluation. Due to a hybrid LSPMSM rotor including both an induction cage and a permanent magnet, torque mechanisms in transient starting and steady-state operating conditions vary. Finite-element analysis (FEA) is commonly used to determine the LSPMSM's synchronization capability. However, this form of verification strategy is costly in terms of calculation. Hence, motor designers and engineers are interested in using a fast and reliable alternative design and optimization approach like analytical methods. Hence, it would be of great significance to develop a design and optimization methodology that allows motor designers to study transient and steady-state performance with high accuracy and low computation time. -- This study presents a strategy to design an optimum line-start permanent magnet synchronous motor (LSPMSM) with improved performance in both transient (dynamic operation to reach synchronous speed) and steady-state (operating with constant synchronous speed). A mathematical design and optimization method, based on the developed machine sizing equations of induction motors (IMs) and permanent magnet (PM) motors, is proposed for the design of an optimum LSPMSM. The rotors of the IM and IPM are combined to create a hybrid rotor including an induction cage and permanent magnet for a LSPMSM. To verify the proposed mathematical method, a three-phase, 4-pole 4-kW LSPMSM is selected as a case study. A second case study of a three-phase, 1-kW, 8-pole LSPMSM is studied for further verification. The initial designs of the IM, IPM motor and LSPMSM are analyzed using FEM to verify the proposed analytical design and analysis method. The IM and IPM are then analytically optimised using a genetic algorithm (GA) for the transient improvement (through maximizing the starting torque) and the steady-state performance improvement (via maximizing efficiency), respectively. The rotor cage bar dimensions and PM size are selected as optimisation variables in optimizing the IM and the IPM. Combining the rotors of the optimised IM and IPM yields the optimum hybrid rotor for the LSPMSM. To present a comparative study between the proposed optimisation method and FEM optimisation, the 2D design of an initial LSPMSM design is optimised based on FEM in Ansys/Maxwell. The designed LSPMSM meets the super-premium efficiency (IE4) standards, which outperforms the benchmark IM standard of premium efficiency (IE3). Also, the designed LSPMSM has the capability of starting directly whilst the benchmark PM motor requires an external driver to start. -- In addition, this study presents a novel analytical thermal analysis model based on a lumped-parameter model of the LSPMSMs. Hence, a lumped-parameter thermal circuit is proposed for LSPMSMs based on the developed thermal model of an IM. To verify the proposed analytical thermal model, a 3-phase, 4-pole 3-kW IM is selected as a case study incorporated with thermal experimental test results from a 3-kW commercial IM to validate the results of the proposed thermal model. The performance of the proposed thermal model of the LSPMSM is verified using 3D FEM-based thermal analysis. In this section of the thesis (thermal analysis and modeling), the LSPMSMs are researched to discover the achievable maximum output power in the same frame size (3-kW and 4-kW commercial induction motors) with successful synchronization and safe operation in terms of temperature rise. -- In summary, the imperative of this study proposes a novel analytical electromagnetic and thermal design, analysis and optimization platform of line-start permanent magnet synchronous motors (LSPMSMs). The main contributions made in this thesis are: (a) simultaneous starting torque and efficiency improvements of the LSPMSM designed based on the commercial IM via implementing optimization using FEM techniques; (b) comparing the performance of two different optimization approaches (gradient-free and gradient-based approaches) in the context of electric machines with a focus on the IMs and LSPMSMs; (c) developing an analytical design, analysis and optimization platform for the LSPMSMs using machine sizing techniques of IMs and permanent magnet (PM) motors; (d) proposing an analytical thermal model and analysis of the LSPMSMs based on lumped-parameter network.

Author: Juha Laurila
Publisher:
ISBN:
Category : Electric engineering
Languages : en
Pages : 66

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Author: Dhamodaran. Nidhesh
Publisher: BoD – Books on Demand
ISBN: 3737610215
Category : Technology & Engineering
Languages : en
Pages : 214

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Book Description
The requirements of an electrical machine (EM) in Electric- (EV) and Hybrid Electric Vehicles (HEV) are high power density, a stator and rotor field with low harmonic content and best acoustic behavior. Six-phase permanent magnet synchronous machines (PMSM) have significant benefits over conventional three-phase PMSMs, such as reduced current per inverter phase leg, less fundamental losses because of a better winding factor and increased fault tolerance. Despite their advantages, considering the same installation space, the torque per ampere increase of a six-phase PMSM is very marginal. Therefore, the main focus of this dissertation lies in increasing the power density of the multiphase electric drive, where optimizations and investigations are done on a system level. System level simulation models, which consist of the power electronics, different control strategies and the electrical machines are developed and studied. Considering the electrical and mechanical phase shift between the two three-phase winding sets, different winding concepts of the sixphase EM are developed, in an effort to gain a better understanding of their advantages and disadvantages. Detailed analyses are performed, in order to understand the sources and influences of the space harmonics and high frequency inverter-induced time harmonics on the losses and performance of the EM. In particular, this dissertation will examine the EM torque, iron losses, magnet losses and copper losses for both inverter switched currents and sinusoidal currents supply.

Author: Sandra Eriksson
Publisher: MDPI
ISBN: 3039213504
Category : Technology & Engineering
Languages : en
Pages : 282

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Book Description
Interest in permanent magnet synchronous machines (PMSMs) is continuously increasing worldwide, especially with the increased use of renewable energy and the electrification of transports. This book contains the successful submissions of fifteen papers to a Special Issue of Energies on the subject area of “Permanent Magnet Synchronous Machines”. The focus is on permanent magnet synchronous machines and the electrical systems they are connected to. The presented work represents a wide range of areas. Studies of control systems, both for permanent magnet synchronous machines and for brushless DC motors, are presented and experimentally verified. Design studies of generators for wind power, wave power and hydro power are presented. Finite element method simulations and analytical design methods are used. The presented studies represent several of the different research fields on permanent magnet machines and electric drives.

Author: Wei Xu (Electrical engineering teacher)
Publisher:
ISBN: 9781003320128
Category : Electric motors
Languages : en
Pages : 0

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Book Description
"Permanent magnet synchronous motors (PMSMs) have been used in the field of electric vehicles due to their high-power density, large torque to inertia ratio, and high reliability. This book presents an improved Field-oriented control (FOC) strategy, for optimal proportional-integral (PI) parameters for robust stability, faster dynamic response, and higher efficiency in the flux-weakening region. Combined design of a PI current regulator and a varying switching frequency PWM is presented, including improved linear model predictive control (MPC) control strategy. This book is aimed at researchers and graduate students in electrical Engineering, systems and control, and electric vehicles. Features: Implements evolutionary optimization algorithms are directly implemented to improve Permanent Magnet Synchronous Machines (PMSM) performance. Provides coverage of PMSM control design in the flux weakening region. Proposes a modern control method of model predictive control is proposed to improve the dynamic performance of interior PMSM. Studies the dynamic performance of two kinds of the PMSMs that of surface mounted and interior permanent magnet types. Includes several case studies and illustrative examples with MATLABa. This book is aimed at researchers, graduate students, and libraries in electrical engineering with specialization in systems and control and electric vehicles"--