Rotating Electrical Machines: Types, Applications and Recent Advances

The Rotating Electrical Machines (REMs) are classified into Motors and Generators. They powered the industrial, domestic and commercial loads. Because of their importance. This paper discussed different types of REMs, their applications and recent advances. REMs are applied in Teaching, Domestic, Mechatronics, Motorcycle, Three-wheelers, Electric Vehicle, Healthcare, Flywheel Energy Storage and Wind Energy Conversion Systems. It periscopes the advances of REMs in design, Fault diagnostic, control and condition monitoring. Its significance is to shed light on some advances made in REM

Demagnetization analysis of an open-end windings 5-phase PMSM under transistor short-circuit fault

For an open-end windings integrated Permanent Magnet Synchronous Machine, the demagnetization of the permanent magnets is analyzed when a transistor is short-circuited and no specific control strategy is adopted. Depending on the temperature, the high currents due to the inverter fault may locally demagnetized the permanent magnets leading to an accelerated aging of the machine and torque loss. A co-simulation, using a Finite Element software for the machine coupled with an average modeling of the transistor, gives interesting local prediction of the machine behavior in healthy and degraded mode.This work has been achieved within the framework of CE2I project. CE2I is co-financed by European Union with the financial support of European Regional Development Fund (ERDF), French State and the French Region of Hauts-de-France

Power Loss Analysis in Thermal Design of Permanent Magnet Machines:A Review

This paper reviews recent developments in power loss analysis applicable, but not limited to, the thermal design of permanent magnet (PM) machines. Accurate and computationally efficient loss prediction is an essential element in thermal analysis of electrical machines, and has become an increasingly important part of the machine design process.The continuous drive toward ‘more electric’ technologies has resulted in a need for a more comprehensive and detailed design approach, where various multi-physics and multi-disciplinary effects are accounted for. This ‘design for application’ methodology relies strongly on the advancements and evolution of the existing theoretical and experimental design techniques to satisfy the evermore-demanding machine design requirements. The thermal behaviour and efficiency of the power conversion are essential performance measures, in the ‘design for application’ approach.An overview of the challenges and limitations regarding power loss analysis in the context of thermal design of electrical machines is provided in this paper. All of the major loss components associated with the active parts of a machine assembly are discussed

Hysteresis Losses in Sintered NdFeB Permanent Magnets in Rotating Electrical Machines

Permanent magnet (PM) materials are nowa- days widely used in the electrical machine manufacturing industry. The eddy-current loss models of PMs used in electrical machines are frequently discussed in research papers. In magnetic steel materials we have, in addition to eddy-current losses, there are hysteresis losses when alter- nating current or a rotating flux travels through the material. Should a similar phenomenon be also taken into account in calculating the losses of PMs? Every now and then, authors seem to assume that some significant hysteresis losses are present in rotating machine PMs. This paper studies the mechanisms of possible hysteresis losses in PMs and their role in PMs when used in rotating electrical machine

Losses Analysis in Electric Machines under Special Conditions

Tato práce se zabývá analýzou magnetických ztrát v elektrických strojích a možnostmi jejich měření. Magneticky měkké i tvrdé materiály jsou velmi náchylné na změnu magnetických vlastností. Lze je měnit pouhou změnou teploty materiálu nebo indukováním různého pnutí uvnitř materiálu a díky tomu dosáhnout rozdílných výsledků. Tyto změny je důležité mít na paměti při návrhu elektrického stroje. Původní parametry v ovlivněných matriálech lze obnovit opětovným vystavením magnetickému poli, žíháním nebo broušením. Zmíněné metody uvolňují indukované pnutí uvnitř materiálu. Kromě analyzování těchto vlivů je důležité znát i způsob měření magnetických parametrů. Každý způsob má svá specifika a zanáší do měření určitou chybu. Při konstrukci stroje pro vyšší účinnosti, vyšší otáčky nebo vyšší teploty je vhodné vědět, jak se magnetické vlastnosti změní. Tato práce pojednává o vlastnostech různých materiálů, jejich měření, a nakonec i aplikaci zjištěných výsledků na zvoleném elektrickém stroji.This thesis deals with the analysis of magnetic losses in electrical machines and the possibilities of their measurement. Magnetically soft and hard materials are very prone to changing magnetic properties. They can be changed simply by changing the temperature of the material or different stresses induced in the material, resulting in different results. These changes are important to keep in mind when an electric machine is being designed. The original parameters of the affected materials can be restored by annealing or grinding. These methods release the induced stresses within the material. Due to these effects, it is also important to know how to measure magnetic parameters. Each way has its own specifics and has a certain error of the measurement. When the machines for higher efficiency, rpm or higher temperatures are designed, it is advisable to know how their magnetic properties changed. This thesis deals with the properties of different materials, their measurements and finally simulation of the chosen electric machine with the application of the measured results.

Axial field permanent magnet machines with high overload capability for transient actuation applications

This thesis describes the design, construction and testing of an axial field permanent magnet machine for an aero-engine variable guide vane actuation system. The electrical machine is used in combination with a leadscrew unit that results in a minimum torque specification of 50Nm up to a maximum speed of 500rpm. The combination of the geometry of the space envelope available and the modest maximum speed lends itself to the consideration of an axial field permanent magnet machines. The relative merits of three topologies of double-sided permanent magnet axial field machines are discussed, viz. a slotless toroidal wound machine, a slotted toroidal machine and a yokeless axial field machine with separate tooth modules. Representative designs are established and analysed with three-dimensional finite element method, each of these 3 topologies are established on the basis of a transient winding current density of 30A/mm2. Having established three designs and compared their performance at the rated 50Nm point, further overload capability is compared in which the merits of the slotless machine is illustrated. Specifically, this type of axial field machine retains a linear torque versus current characteristic up to higher torques than the other two topologies, which are increasingly affected by magnetic saturation. Having selected a slotless machine as the preferred design, further design optimization was performed, including detailed assessment of transient performance. A key feature of this design is the use of a solid (i.e. non-laminated) toroidal stator core. This provides a stator with increased mechanical robustness, improved heat transfer and a ready means of incorporating fixing points into the core. However, these advantages are gained at the expense of a significant eddy currents in the stator core. A series of three-dimensional, magneto-dynamic finite element simulations were performed. Although the resulting eddy current losses are excessive for continuous operation, the reduction in transient performance which results from the eddy currents is shown to be manageable. The loss analysis is supplemented by transient three-dimensional finite element thermal modelling. Three-dimensional mechanical analysis is performed in combination with analytical equation to analyse the stator and rotor plate deflection subject to axial attractive force. The construction of a prototype double-sided axial field machine is described in this thesis which contains several interesting design features including a profiled rotor core to reduce mass, radially magnetised rotor magnets to produce torque from the axially oriented conductors on the inner edge of the toroidal winding. The testing of the machine is performed under a series of load points up to 75Nm to validate the predicted torque versus current density characteristics

Mathematical Models for the Design of Electrical Machines

This book is a comprehensive set of articles reflecting the latest advances and developments in mathematical modeling and the design of electrical machines for different applications. The main models discussed are based on the: i) Maxwell–Fourier method (i.e., the formal resolution of Maxwell’s equations by using the separation of variables method and the Fourier’s series in 2-D or 3-D with a quasi-Cartesian or polar coordinate system); ii) electrical, thermal and magnetic equivalent circuit; iii) hybrid model. In these different papers, the numerical method and the experimental tests have been used as comparisons or validations