<p>This licentiate thesis describes the modeling and measurements performed with the aim of developing design guidelines for Line Start Permanent Magnet Synchronous Motors, LSPMSMs. LSPMSMs can offer higher efficiency than standard induction motors used in the industry today, especially for small motor sizes. The increase in efficiency results in lower environmental impact and reduced electricity cost. The LSPMSM has, however, several drawbacks, among the most important is the reduced starting capability compared to induction motors. Furthermore, the rotor construction is complex and the added cost of magnet material makes the LSPMSM a comparably expensive motor type. The design of a LSPMSM is a trade-off between starting capability and steady state performance. The thesis discusses these trade-offs and the models that can be used as a basis for design and optimization. The models make use of different motor parameters, and a number of measurement methods for measuring these parameters are described and compared. Among these is a step response adapted measurement method that provides most of the parameters of interest. The development and setup of a brake bench for measuring both start-up and steady state performance is presented. Furthermore the start-up behavior and steady-state performance is calculated using measured parameters. The calculated performance is compared to measured performance and found to correlate well for nominal operating conditions. Thus, design guidelines can be based on the models proposed.</p>

Dans le cadre de la réduction des émissions des gaz à effet de serre, et devant l'augmentation incessante du prix de l'énergie, la course à l'amélioration des performances énergétiques touche tous les secteurs : industriel, tertiaire ou même celui des particuliers. La consommation de l'énergie électrique est due en grande partie aux moteurs électriques, et particulièrement les machines asynchrones, utilisées dans diverses applications telles que le pompage, la ventilation ou la compression. Ces machines sont caractérisées par des rendements relativement faibles et leur remplacement par des machines plus performantes permettrait un gain d'énergie non négligeable. Les machines à aimants permanent ayant pouvoir de démarrage autonome sont de bonnes candidates pour répondre à ce besoin. Elles ont de très bons rendements et les artifices supplémentaires permettant le démarreur automne suppriment la nécessité d'utiliser des convertisseurs statiques comme dans le cas des machines à aimants classiques. Des contraintes spécifiques se posent cependant pour l'utilisation et le dimensionnement de ces machines : en effet, le courant de démarrage ne doit pas être trop important à cause du risque de démagnétiser les aimants et le couple de démarrage doit être suffisamment grand pour assurer un démarrage en charge. Par ailleurs les rendement et facteurs de puissance en pleine charge doivent être assez nettement supérieurs à ceux des machines asynchrones pour les rendre plus compétitives. Dans cette thèse, nous étudions trois structures de rotor permettant de répondre à un cahier des charges donné. Ces trois structures utilisent des aimants en surface, insérés dans un rotor massif ou dans un rotor à cage. Elles ont leurs avantages et leurs inconvénients, que nous avons mis en évidence par une étude comparative assez détaillée. Cette étude comparative n'a pu être mise en oeuvre sans l'établissement de modèles en régime statique ou dynamique de ces machines ou encore de méthodologie de conception. Un prototype à échelle réduite a été dimensionné, réalisé et testé au laboratoire ; il confirme les principes de base de ce type de machines / In the context of reducing emissions of greenhouse effect, and of energy cost, the competition to improve the performances of the equipments affects all the domains. The consumption of electricity is mostly due to the electric motors, and particularly induction machines, used in various devices such as pumps, fans or compressors. These machines are characterized by relatively low efficiencies, and their replacement by more efficient machines should lead to a significant power saving. The Line-Start Permanent Magnet motors are good candidates to achieve this purpose. They have higher efficiencies and the additional devices for self-start eliminates the need of static converters, as it is normally required for conventional permanent magnet motors. Specific constraints arise for the use and the design of these machines: the starting current should not be so high to avoid the risk of the demagnetization of magnets and the starting torque must be large enough to ensure the start under load. Moreover, the efficiency and power factor at full load must be sufficiently higher than those of asynchronous machines in order to make them more competitive. In this thesis, we study three rotor structures to meet a given specification. These three structures use magnets inserted on the surface, embedded in a solid rotor or a cage rotor. They have their advantages and drawbacks that we have shown by a comparative study in some detail. This comparative study could not be implemented without the development of models in both static and dynamic conditions of these machines and a specific design methodology. A small scale of prototype has been designed, built and tested in the laboratory; it confirms the basic principles of such machines

This licentiate thesis describes the modeling and measurements performed with the aim of developing design guidelines for Line Start Permanent Magnet Synchronous Motors, LSPMSMs. LSPMSMs can offer higher efficiency than standard induction motors used in the industry today, especially for small motor sizes. The increase in efficiency results in lower environmental impact and reduced electricity cost. The LSPMSM has, however, several drawbacks, among the most important is the reduced starting capability compared to induction motors. Furthermore, the rotor construction is complex and the added cost of magnet material makes the LSPMSM a comparably expensive motor type. The design of a LSPMSM is a trade-off between starting capability and steady state performance. The thesis discusses these trade-offs and the models that can be used as a basis for design and optimization. The models make use of different motor parameters, and a number of measurement methods for measuring these parameters are described and compared. Among these is a step response adapted measurement method that provides most of the parameters of interest. The development and setup of a brake bench for measuring both start-up and steady state performance is presented. Furthermore the start-up behavior and steady-state performance is calculated using measured parameters. The calculated performance is compared to measured performance and found to correlate well for nominal operating conditions. Thus, design guidelines can be based on the models proposed. / QC 20101112

Diplomová práce se zabývá topologickou optimalizací elektrických strojů a reluktančními synchronními stroji spouštěnými za sítě. Práce obsahuje literární rešerši na téma topologické optimalizace elektrických strojů a na téma synchronní reluktanční stroj spouštěný ze sítě. Jsou zde popsány možné způsoby charakterizace optimalizovaného prostoru. Především je rozebrán vliv rozmístění Gaussových funkcí na finální Gaussovu síť. V této práci je vytvořen vyhodnocovací algoritmus pro jednotlivé jedince, který zajišťuje komunikaci mezi Ansys Maxwell a optimalizačním softwarem SyMSpace. Navíc tento algoritmus vede ke zkrácení výpočetní doby počáteční selekcí nevyhovujících jedinců. Dále je provedena topologická optimalizace LSSynRM s využitím normalizované Gaussovy sítě a zhodnocení výsledků.

In this thesis different methods of optimizing line start permanent magnet motor (LSPM) for magnet cost reduction is studied. Influence of different parameters has been studied by simulating magneto-static and transient FEM models of the machine. Finally a motor design of a LSPM with high rotor saliency has been proposed. The first method investigated is the use of flux barriers in LSPM and its effect on the magnetic flux leakage. The flux barriers reduce the flux leakage and hence help in reducing magnet volume. The second method studied is the use of two different grades of magnets. Using low price magnets help in reducing the total magnet cost without reducing the air gap flux density. The reduction in NdFeB magnet volume is not substantial by using both the methods mentioned above. The third method investigated is increasing the saliency of the rotor by introducing flux barriers and reducing the corresponding magnet volume. Both the magneto static and transient models are used to study the effect of different parameters of the motor. The placement and volume of magnet plays a critical role in motor performance. At first, the developed reluctance torque of the motor is maximized by doing parametric study and then magnets are placed in slots to achieve the required efficiency and power factor. The motor is simulated with NdFeB magnets and with Ferrite magnets. It has been found that using high saliency LSPM motor the NdFeB magnet volume can be reduced significantly. It is also shown that the same performance of motor (as compared to the motor with NdFeB magnets) can be achieved by using Ferrite magnets. The volume of Ferrite magnet required will be larger but still cost-wise using Ferrite is an attractive choice. Therefore, a design of motor is proposed using both NdFeB magnets and Ferrite magnets. Finally, the performance of proposed LSPM motor with high saliency is compared with that of an induction motor.

Ce travail a pour objectif de développer un outil analytique multi-physiques de dimensionnement d’une gamme de moteurs « hybrides » à démarrage direct, intégrant les avantages des deux technologies : l’auto-démarrage de la technologie asynchrone et les bonnes performances énergétique en régime permanent de la technologie synchrone à aimants permanents en répondant aux nouveaux enjeux d’efficacité énergétique et en ajoutant à cela les aspects économiques.La validation de cet outil est effectuée par des modèles éléments finis créés avec un logiciel commercial ANSYS/Maxwell et par des essais expérimentaux réalisés à l’aide de deux prototypes LSPMSM 7.5kW. / This work aims to develop a multi-physical generic model (and a pre-design software) for a range of LSPMSMs which would integrate the advantages of both technologies: self-start asynchronous technology and good energy performance of synchronous permanent magnet technology. The validation of this model is carried out by finite element commercial software ANSYS / Maxwell and by experimental tests using two 7.5kW.LSPMSM prototypes.