Considerations on the effects that core material machining has on an electrical machine's performance

An often-overlooked aspect during the development process of electrical machines, is the validity and accuracy of the machine material properties being used at the design stage. Designers usually consider the data provided by the materials supplier, which is measured on material in an unprocessed state. However, the fact that the machining processes required to produce the finished product (e.g. the stator core) can permanently vary the material properties is very often neglected. This paper therefore deals with and investigates the effects that such processes can have on the overall machine performance. To do this, three sets of material data, based on 1) the materials suppliers’ data, 2) materials data based on conventional characterization methods and 3) materials data based on test samples that include the manufacturing processes, are used to develop three versions of the same baseline machine. The results of these three machines are then compared and the resulting variations of the machine’s performance presented and described. The chosen baseline machine is a high performance and relatively high speed, aerospace, electrical machine. Special attention is focused on the efficiency maps of the machine as this aspect is highly dependent on the material properties that are the most sensitive to manufacturing processes such as the material’s anhysteretic BH curve and its specific core loss

Axial eccentric SynRel and SPM Motors analytical models validation using 3D finite element

This paper deals with the uniform and non-uniform axial eccentricity analyses of the surface mounted permanent magnet and synchronous reluctance machines. The analyses are carried out using an analytical model for each considered machine. Being the axial eccentricity a 3D physical phenomenon, the standard sliding approach used in the analytical models has been validated through accurate 3D FE simulations. The results presented in this paper verify the effectiveness of the analytical approaches quantifying the results deviations respect to the computational expensive 3D FE simulations. The results also confirms that synchronous reluctance machines show higher radial forces compared to the surface permanent magnet machines for the same eccentricity level, main geometry and operating condition

Thermal management of a permanent magnet motor for an directly coupled pump

A high speed permanent magnet motor is designed for a flooded industrial pump. Oil in the pump is used to cool the motor. Due to the limitation of space and mass requirement for the application, thermal management is one of the main challenges. This paper describes the thermal management optimization process and design of the machine. Different cooling strategies are applied to cool the machine and Computational Fluid Dynamics (CFD) is used to predict and improve the cooling performance. The machine has been designed and is currently being manufactured

Comparative study of permanent magnet-synchronous and permanent magnet-flux switching machines for high torque to inertia applications

This paper investigates the capability of both permanent magnet synchronous machine (PMSM) and permanent magnet flux switching (PMFS) machine to provide high torque to inertia ratio for applications with demanding response in terms of acceleration and fast dynamic. The PMSM has higher torque density and efficiency among different electrical machines. However, the presence of the permanent magnets can increase the rotor inertia. Thanks to its passive salient-pole rotor, PMFS machine is a suitable solution for those applications requiring lower inertia. This paper provides a comparative analysis between the PMSM and PMFS machines considering the torque to inertia ratio, the challenges of a flooded air gap and dimensional constraints. The electromagnetic performances of both machines have been evaluated by means of finite element method and a detailed sensitivity analysis is carried out for stator and rotor geometry

Trade-off analysis and design of a high power density PM machine for flooded industrial pump

This paper presents the trade-off analysis and design of a high power-density machine for industrial pump applications. The developed permanent magnet synchronous machine drives an electric, oil flooded pump. Different slot/pole combination and winding configuration have been investigated in order to identify the optimal combination that satisfies the electromagnetic and thermal constraint while keeping the losses as small as possible. Several strategies such as the use of the Cobalt iron material for the stator core lamination and the adoption of Halbach array have been investigated in this work to improve the performance capabilities of the designed machine. The electromagnetic performances have been evaluated by using a finite element method. Thermal behaviour has been determined using a lumped parameter network. The outcome of the thermal analysis helped to identify the optimal cooling configurations. The final results are presented highlighting the achieved design targets

Design and optimization of a high power density machine for flooded industrial pump

This paper presents the design optimization procedure of a high power-density, permanent magnet synchronous machine for industrial pump applications. The designed machine drives an electric, oil flooded pump. In order to achieve higher torque-density, a fractional slot machine (8 poles, 9 slots) with double layer (concentrated) winding has been selected after a preliminary trade-off study, which considered several slot/pole combinations and winding configurations. The developed machine provides low torque ripple and short end windings, which contribute to lower axial length and higher efficiency. The electromagnetic performances have been evaluated by using finite element method and the lamination geometry has been optimized through a genetic. The final results are presented highlighting the achieved design targets

Association of The Mthfr C677t, Factor V (Leiden) G1961a and Prothrombin G20210a Gene Mutations with Recurrent Spontaneous Aboration (Rsa) in Duhok Province

Genetic causes of thrombophilia have been suggested as a possible cause of recurrent pregnancy loss (RPL). Fifty female patients aged between 21- 40 years and experienced at least two times early pregnancy loss were enrolled in the current study. Blood samples were aspirated, infectious (TORCH), hormonal (gonadotrophines, steroids, and thyroid hormones), ultrasonic, and serological (anti-lupus and anti-phospholipid antibodies) evaluations were conducted to exclude any individual candidate who had been suspected to have causes of early pregnancy loss rather than the genetic attribute. DNA from each particular sample was extracted by components of (FVL-PTH and MTHFR)StripAssay®A kit Vienna Lab Diagnostics GmbH, Vienna, Austria).this kit includes three steps: (1) DNA isolation, (2) Multiplex PCR amplification was performed by using biotinylated primers, for detecting different mutations in the three genes of interest (FVL-PTH and MTHFR) (3) Hybridization of amplification products to a test strip containing allele-specific oligonucleotide probes immobilized as an array of parallel lines. The results revealed that 24 samples out of 50 had MTHFR C677T mutations while 2 samples only had   FV (G1691A)mutation while prothrombin mutation (G20210A)has not been detected. In conclusion: genetic mutation had significant impact in patients suffered recurrent pregnancy loss

Processing Traffic Jam in Al-Sadrain Intersection in the Holy City of Najaf

Modern metropolitan cities worldwide suffer from heavy congestion due to high daily commutes for various purposes. Intersections are the most congested component of the network and represent the sites of accidents. At the same time, the intersection (Al-Sadrien) in Al- Najaf Al-Ashraf city is regarded as one of the major important intersections. Typically, this intersection increases the volume of traffic during rush hours, which raises traffic congestion, Therefor, the problem with this article is that unclear how the distribution of the surrounding areas affects traffic accidents and junction congestion. Our hypothesis to solve the problem is that an important relationship must be clear between the intersection and its surrounding areas. In this study, analysis the current service of intersection as field survey adopting the analytical approach using simulation by HCS2010 and VISSIM software, based on GIS that showed: the eastern approach (coming from Al- Kufa) was (F) (3.18.97), the result of the western approach (coming from Najaf) (F) (3.45.49), and the result of the northern approach (coming from the College of Administration and Economics) (D) (1.38). 83) and the result of the southern approach (coming from Al- Rawan Street) (E) (1.14.13). When the times of delay to the level of service intersection, as adopted by the capacity of roads on the program (HCS 2010), amounted to more than (800) seconds/vehicle at peak times. So, the classification of service at this intersection is in level (E). Through the traffic intersection analysis, recommendations and proposals must be taken before any decisions regarding land use , which has effects on the city

Thermal management of a permanent magnet motor for an directly coupled pump

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Evaluation of strand-to-strand capacitance and dissipation factor in thermally aged enamelled coils for low-voltage electrical machines

© The Institution of Engineering and Technology 2019. The dissipation factor (i.e. tanδ) and insulation capacitance (IC) measurements are conventional monitoring methods for assessing the aging level of insulation systems. These quantities provide an invaluable indication of the dielectric losses within the insulating materials. However, how these values are affected by the aging processes due to thermal stresses have until today never been investigated fully. Thus, this study exhibits the influence of thermal aging on tanδ and IC of windings for electrical machines (EMs). The work is performed for class 200, round enamelled magnet wire specimens. The study aims at improving the design process of EMs for short duty cycle applications; hence, its outcome might be included at the design stage for enhancing reliability and lifetime. Random wound coils are chosen in the performed study, because they are the most common winding arrangement for low-voltage EMs, which are employed in a wide range of applications (e.g. from home appliances to aerospace motors). Based on the collected data, considerations regarding the impact of relative humidity on both the dissipation factor and IC are presented. Finally, the correlation between the partial discharge inception voltage and the diagnostic measurements is experimentally verified