Advanced design methodology for permanent magnet synchronous machines in power applications

Most of the world electrical energy is consumed by electric motors, and then, the improvement in their performance leads to essential savings in the global energy consumption, required to reduce the CO2 emissions. Actually, the policies of governments and institutions are becoming more demanding and the manufacturers are forced to offer more and more optimized products. Moreover, many applications are increasingly demanding high performance in terms of power density, reliability or dynamic response, as in the case of electric vehicle, wind power generation or railway traction. The high energetic content of neodymium magnets causes that the permanent magnet machines (PMSM) are the more attractive option with respect to power density. In addition, thanks to the almost complete elimination of the rotor losses they are the most energetically efficient machines. The PMSM design requires of a multiphysical approach since it comprises electric, magnetic and thermal aspects. In this work, a comprehensive review of the technical literature regarding these machines has been done, and some areas for improvement have been found. Firstly, it is common that the procedure starts from a quite defined machine and just an optimization of a specific part is realized. Moreover, excessive dependence on designer’s experience and knowhow is observed, without giving clear instructions for taking design decisions. Finally, excessive dependence on time consuming FEM models is found. Hence, the main objective of this thesis is to develop and propose an advanced design methodology for PMSM design, characterized by being clear and complete, considering whole the design process and giving criteria and tools for taking decisions which lead to an optimum choice of the final solution. A PMSM design methodology has been proposed that enables the evaluation of large amounts of configurations in an automatic manner, easing to the designer the process of taking the final design decision. To implement this methodology, several tools have been developed and explained in detail: electromagnetic models coupled to thermal models and lumped parameter electromagnetic models. Some important modifications were done in the thermal models taken as a reference in order to consider different cooling conditions. In addition, a basis permeance network model was adapted to the selected machine topology and it was used to demonstrate its suitability to be used in combination with Frozen Permeability technique. Following the proposed design methodology, a 75 kW PMSM prototype was designed and validated at the IK4‐IKERLAN medium voltage laboratory. The obtained results have validated both the proposed design methodology and the developed and employed tools.La mayor parte de la energía eléctrica mundial es consumida en motores eléctricos, por lo que la mejora de sus prestaciones conduce a ahorros en el consumo energético esenciales si se quieren reducir las emisiones de CO2. De hecho, las políticas de gobiernos y asociaciones cada vez son más exigentes, y los diseñadores se ven forzados a lanzar productos cada vez más optimizados. Además, cada vez hay más aplicaciones que son muy exigentes en términos de densidad de potencia, fiabilidad o prestaciones dinámicas, como son el vehículo eléctrico, la generación eólica o la tracción ferroviaria. El altísimo contenido energético de los imanes de neodimio provoca que las máquinas imanes permanentes (PMSM) sean las más atractivas en términos de densidad de potencia. Además, debido a la casi total eliminación de pérdidas en el rotor se convierten en las máquinas más eficientes energéticamente. El diseño de una PMSM requiere de un enfoque multidisciplinar, ya que engloba aspectos eléctricos, magnéticos y térmicos. En este trabajo, se ha realizado una revisión exhaustiva de la literatura técnica publicada hasta la fecha en relación con el diseño de estas máquinas, y se han encontrado ciertos puntos de mejora. En primer lugar, muchas veces se parte de un diseño bastante definido y se optimiza una parte concreta del mismo. Además, se aprecia excesiva dependencia de la experiencia y knowhow del diseñador, sin establecer pautas claras para la toma de decisiones de diseño. Finalmente, dependen excesivamente del temporalmente costoso FEM. Por lo tanto, el objetivo principal de esta tesis es desarrollar una metodología avanzada de diseño de PMSMs que sea clara y completa, abarcando todo el proceso de diseño y aportando criterios y herramientas para la toma de decisiones que conduzcan a una elección óptima de la solución final. Se ha propuesto una metodología de diseño que permite la evaluación de gran cantidad de configuraciones de PMSM de forma automática, facilitando la decisión de diseño final por parte del diseñador. Para la implementación de esta metodología, diversas herramientas han tenido que ser desarrolladas y son explicadas en detalle: modelos analíticos electromagnéticos acoplados con modelos térmicos, y modelos electromagnéticos de parámetros concentrados. Importantes modificaciones fueron realizadas sobre los modelos térmicos adoptados para considerar diferentes refrigeraciones. Además, el circuito electromagnético de parámetros concentrados fue adaptado a la topología seleccionada y demostró su validez para ser utilizado en combinación con la técnica de Frozen Permeability. Siguiendo la metodología propuesta, se ha diseñado y fabricado un prototipo de 75 kW y se ha realizado la validación experimental en el laboratorio de media tensión de IK4‐IKERLAN. Los resultados obtenidos han servido para validar tanto la metodología de diseño como las herramientas empleadas en la misma.Munduko energia elektrikoaren zatirik handiena motor elektrikoetan kontsumitzen da, eta, ondorioz, prestazioak hobetzeak lagundu egiten du kontsumo energetikoan funtsezko aurrezpenak egiten, CO2 igorpenak murriztu nahi badira. Berez, gobernuen eta elkarteen eskakizunak gero eta zorrotzagoak dira, eta diseinatzaileak produktu gero eta optimizatuak atera beharrean daude. Gainera, gero eta aplikazio gehiago daude zorroztasun handia eskatzen dutenak potentzi dentsitateari, fidagarritasunari edo prestazio dinamikoei dagokienez, esaterako, ibilgailu elektrikoan, sorkuntza eolikoan edo tren trakzioan. Neodimiozko imanen eduki energetiko itzelaren ondorioz, iman makina iraunkorrak (PMSM) dira erakargarrienak potentzi dentsitateari dagokionez. Gainera, errotorearen galerak ia guztiz deuseztatzen direnez, energetikoki makinarik eraginkorrenak dira. PMSM bat diseinatzeko diziplina askoko ikuspegia behar da, alderdi elektrikoak, magnetikoak eta termikoak hartzen baititu bere baitan. Lan honetan orain arte honelako makinen diseinuari buruz argitaratutako literatura teknikoaren azterketa zehatza egin da, eta hobetzeko hainbat puntu aurkitu dira. Lehenik eta behin, askotan, abiapuntua nahiko definituta dagoen diseinu bat izaten da, eta egiten dena da horren zati jakin bat optimizatu. Gainera, gehiegizko mendekotasuna egoten da diseinatzailearen esperientzia eta knowhow‐arekiko, diseinuaren inguruko erabakiak hartzeko jarraibide argiak ezarri gabe. Azkenik, mendekotasun handia dago FEMek behin‐behinean duen kostu handiarekiko. Horrenbestez, tesiaren helburu nagusia da PMSMak diseinatzeko metodologia aurreratu bat garatzea, argia eta osatua, diseinuaren prozesu osoa hartuko duena, eta erabakiak hartzeko irizpideak eta tresnak eskainiko dituena, amaierako soluziorik onena aukeratu ahal izateko. Diseinurako proposatu den metodologiarekin PMSMko konfigurazio kopuru handi bat ebaluatu daiteke automatikoki, diseinatzaileari amaierako diseinua erabakitzen laguntzeko. Metodologia inplementatzeko, hainbat tresna garatu behar izan dira, eta horiek zehatz esplikatzen dira: eredu analitiko elektromagnetikoak, eredu termikoekin uztartuta, eta parametro kontzentratuen bidezko eredu elektromagnetikoak. Hautatutako eredu termikoetan aldaketa garrantzitsuak egin behar izan ziren, hozkuntza desberdinak lantzeko. Horrez gain, parametro kontzentratuen zirkuitu elektromagnetikoa hautatutako topologiara egokitu zen, eta bere balioa frogatu zuen, Frozen Permeability teknikarekin konbinatuta erabiltzeko. Proposatutako metodologiari jarraituz, 75 kW‐eko prototipo bat diseinatu eta fabrikatu da, eta balioztapen esperimentala egin da IK4‐IKERLANeko tentsio ertaineko laborategian. Lortutako emaitzek diseinuaren metodologia zein bertan erabilitako tresnak balioztatzeko balio izan dute

Semi-Analytical Approach Towards Design and Optimization of Induction Machines for Electric Vehicles

Electric machine design is a comprehensive task depending on the several factors, such as material resource limitations and economic factors. Therefore, an induction machine is a promising candidate because of the absence of magnetic material in the rotor. However, the conventional design approach can neither reflect the advances of the induction machine(IM) design nor exploit the trade-offs between design factors and the multi-physics nature of the electrical machine. Therefore, proposing fast and accurate novel methods to design, develop and analyze IMs using electromagnetic field oriented approaches is competitive to the old-fashion numerical methods. To achieve improved IM design from a baseline design to an optimal design, this dissertation: (1) Investigates the challenges of the high speed IM design specified for the electric vehicle application at the rated operating condition considering electromagnetic boundaries for the reasonable saturation level within a compact volume; (2) Proposes a new design approach of IM using modified equivalent circuit parameters to reduce spatial harmonics because of slotting effect and skewing effect; and also presents the importance of the 3-D analysis over 2-D analysis while developing the IM; (3) Proposes a novel electromagnetic field oriented mathematical model considering the slotting effect and axial flux variation because of skewing rotor bars to evaluate the IM performance with a lower and precise computational effort; (4) developed baseline IM is optimized with genetic algorithm incorporated in proposed subdomain model to improve the torque-speed profile. In order to further simplify the optimization procedure, a parametric and sensitivity based design approach is implemented to reduce the design variables. To evaluate the proposed optimal IM with extended constant power region and high torque density within a compact volume using novel 3-D subdomain model, the machine has been prototyped and tested from low to high speed under no-load and loaded condition. Electrical circuit parameter variation is demonstrated and compared to the one simulated in the FEA environment. This innovation can be applied to a family of electric machines with various topologies

Performance of Induction Machines

Induction machines are one of the most important technical applications for both the industrial world and private use. Since their invention (achievements of Galileo Ferraris, Nikola Tesla, and Michal Doliwo-Dobrowolski), they have been widely used in different electrical drives and as generators, thanks to their features such as reliability, durability, low price, high efficiency, and resistance to failure. The methods for designing and using induction machines are similar to the methods used in other electric machines but have their own specificity. Many issues discussed here are based on the fundamental achievements of authors such as Nasar, Boldea, Yamamura, Tegopoulos, and Kriezis, who laid the foundations for the development of induction machines, which are still relevant today. The control algorithms are based on the achievements of Blaschke (field vector-oriented control) and Depenbrock or Takahashi (direct torque control), who created standards for the control of induction machines. Today’s induction machines must meet very stringent requirements of reliability, high efficiency, and performance. Thanks to the application of highly efficient numerical algorithms, it is possible to design induction machines faster and at a lower cost. At the same time, progress in materials science and technology enables the development of new machine topologies. The main objective of this book is to contribute to the development of induction machines in all areas of their applications

Power Distribution and Propulsion System for an All-Electric Short-Range Commuter Aircraft—A Case Study

To participate in the transition towards a sustainable use of energy, the aircraft sector needs to be transformed with respect to the energy carrier and propulsion methods. For smaller aircraft, a battery-electric approach is promising. While this will require extensive research and design together with the application of advanced components which are partly not available to this date, general design rules and key parameters and critical components can already be deduced. This publication presents the example design of the full propulsion system for a small commuter aircraft. This serves as a case study to highlight the influence of components and parameters on the overall efficiency and weight of the system. By that, future research can be directed towards the areas of high impact on the realization of all-electric aircraft. A optimization of several motor variants, inverter topologies and power supply grid parameters is performed. The weight of the fully electric propulsion system is dominated by the battery. Therefore, all subsequent components need to be designed towards a high efficiency in opposition to high power density

The investigation of electromagnetic radial force and associated vibration in permanent magnet synchronous machines

The rising public awareness of climate change and urban air pollution has been one of the key drivers for transport electrification. Such trend drastically accelerates the quest for high-power-and-torque-density electric drive systems. The rare-earth permanent magnet synchronous machine, with its excellent steady-state and dynamic characteristics, has been the ideal candidate for these applications. Specifically, the fractional-slot and concentrated-winding configuration is widely adopted due to its distinctive merits such as short end winding, low torque pulsation, and high efficiency. The vibration and the associated acoustic noise become one of the main parasitic issues of high-performance permanent magnet synchronous drives. These undesirable features mainly arise from mechanical connection failure, imperfect assembly, torque pulsation, and electromagnetic radial and axial force density waves. The high-power-and-torque-density requirement will only be ultimately fulfilled by the reduction of both electromagnetic active material and passive support structure. This results in inflated electromagnetic force density inside the electric machine. Besides, the sti.ness of the machine parts can be compromised and the resultant natural frequencies are significantly brought down. Therefore, the vibration and acoustic noise that are associated with the electromagnetic radial and axial force density waves become a burden for large deployment of these drives. This study is mainly dedicated to the investigation of the electromagnetic radial forced density and its associated vibration and acoustic noise in radial-flux permanent magnet synchronous machines. These machines are usually powered by voltage source inverter with pulse width modulation techniques and various control strategies. Consequently, the vibration problem not only lies on the permanent magnet synchronous machine but also highly relates to its drive and controller. Generally, the electromagnetic radial force density and its relevant vibration can be divided into low-frequency and high-frequency components based on their origins. The low-frequency electromagnetic radial force density waves stem from the magnetic field components by the permanent magnets and armature reaction of fundamental and phase-belt current harmonic components, while the high-frequency ones are introduced by the interactions between the main low-frequency and sideband highfrequency magnetic field components. Both permanent magnets and armature reaction current are the main sources of magnetic field in electric machines. Various drive-level modeling techniques are first reviewed, explored, and developed to evaluate the current harmonic components of the permanent magnet synchronous machine drive. Meanwhile, a simple yet e.ective analytical model is derived to promptly estimate the sideband current harmonic components in the drive with both sinusoidal and space-vector pulse width modulation techniques. An improved analytical method is also proposed to predict the magnetic field from permanent magnets in interior permanent magnet synchronous machines. Moreover, a universal permeance model is analytically developed to obtain the corresponding armature-reaction magnetic field components. With the permanent magnet and armature-reaction magnetic field components, the main electromagnetic radial force density components can be identified and estimated based on Maxwell stress tensor theory. The stator tooth structure has large impacts on both electromagnetic radial force density components and mechanical vibration behaviors. The stator tooth modulation e.ect has been comprehensively demonstrated and explained by both finite element analysis and experimental results. Analytical models of such e.ect are developed for prompt evaluation and insightful revelation. Based on the proposed models, multi-physics approaches are proposed to accurately predict low-frequency and high-frequency electromagnetic radial vibration. Such method is quite versatile and applicable for both integral-slot and fractional-slot concentrated-winding permanent magnet synchronous machines. Comprehensive experimental results are provided to underpin the validity of the proposed models and methods. This study commences on the derivations of the drive parameters such as torque angle, modulation index, and current harmonic components from circuit perspective and further progresses to evaluate and decouple the air-gap magnetic field components from field perspective. It carries on to dwell on the analytical estimations of the main critical electromagnetic radial force density components and stator tooth modulation e.ect. Based on the stator mechanical structure, the corresponding electromagnetic radial vibration and acoustic noise can be accurately predicted. Various analytical models have been developed throughout this study to provide a systematic tool for quick and e.ective investigation of electromagnetic radial force density, the associated vibration and acoustic noise in permanent magnet synchronous machine drive. They have all been rigorously validated by finite element analysis and experimental results. Besides, this study reveals not only a universal approach for electromagnetic radial vibration analysis but also insightful correlations from both machine and drive perspectives

Industrial and Technological Applications of Power Electronics Systems

The Special Issue "Industrial and Technological Applications of Power Electronics Systems" focuses on: - new strategies of control for electric machines, including sensorless control and fault diagnosis; - existing and emerging industrial applications of GaN and SiC-based converters; - modern methods for electromagnetic compatibility. The book covers topics such as control systems, fault diagnosis, converters, inverters, and electromagnetic interference in power electronics systems. The Special Issue includes 19 scientific papers by industry experts and worldwide professors in the area of electrical engineering

12th International Conference on Vibrations in Rotating Machinery

Since 1976, the Vibrations in Rotating Machinery conferences have successfully brought industry and academia together to advance state-of-the-art research in dynamics of rotating machinery. 12th International Conference on Vibrations in Rotating Machinery contains contributions presented at the 12th edition of the conference, from industrial and academic experts from different countries. The book discusses the challenges in rotor-dynamics, rub, whirl, instability and more. The topics addressed include: - Active, smart vibration control - Rotor balancing, dynamics, and smart rotors - Bearings and seals - Noise vibration and harshness - Active and passive damping - Applications: wind turbines, steam turbines, gas turbines, compressors - Joints and couplings - Challenging performance boundaries of rotating machines - High power density machines - Electrical machines for aerospace - Management of extreme events - Active machines - Electric supercharging - Blades and bladed assemblies (forced response, flutter, mistuning) - Fault detection and condition monitoring - Rub, whirl and instability - Torsional vibration Providing the latest research and useful guidance, 12th International Conference on Vibrations in Rotating Machinery aims at those from industry or academia that are involved in transport, power, process, medical engineering, manufacturing or construction

12th International Conference on Vibrations in Rotating Machinery

Since 1976, the Vibrations in Rotating Machinery conferences have successfully brought industry and academia together to advance state-of-the-art research in dynamics of rotating machinery. 12th International Conference on Vibrations in Rotating Machinery contains contributions presented at the 12th edition of the conference, from industrial and academic experts from different countries. The book discusses the challenges in rotor-dynamics, rub, whirl, instability and more. The topics addressed include: - Active, smart vibration control - Rotor balancing, dynamics, and smart rotors - Bearings and seals - Noise vibration and harshness - Active and passive damping - Applications: wind turbines, steam turbines, gas turbines, compressors - Joints and couplings - Challenging performance boundaries of rotating machines - High power density machines - Electrical machines for aerospace - Management of extreme events - Active machines - Electric supercharging - Blades and bladed assemblies (forced response, flutter, mistuning) - Fault detection and condition monitoring - Rub, whirl and instability - Torsional vibration Providing the latest research and useful guidance, 12th International Conference on Vibrations in Rotating Machinery aims at those from industry or academia that are involved in transport, power, process, medical engineering, manufacturing or construction

SIRM 2017

This volume contains selected papers presented at the 12th International Conference on vibrations in rotating machines, SIRM, which took place February 15-17, 2017 at the campus of the Graz University of Technology. By all meaningful measures, SIRM was a great success, attracting about 120 participants (ranging from senior colleagues to graduate students) from 14 countries. Latest trends in theoretical research, development, design and machine maintenance have been discussed between machine manufacturers, machine operators and scientific representatives in the field of rotor dynamics. SIRM 2017 included thematic sessions on the following topics: Rotordynamics, Stability, Friction, Monitoring, Electrical Machines, Torsional Vibrations, Blade Vibrations, Balancing, Parametric Excitation, and Bearings. The papers struck an admirable balance between theory, analysis, computation and experiment, thus contributing a richly diverse set of perspectives and methods to the audience of the conference