Modeling, analysis and design of electromechanical systems
Amirhossein Koushki; Zahra Nasiri Gheidari
Abstract
Coreless Permanent Magnet (CPM) machines are increasingly used in many industrial applications, such as automotive and aerospace applications, wind turbines, medical equipment, robotics, servo drives, and so on. In coreless permanent magnet DC machines, the rotor has a coreless winding structure and ...
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Coreless Permanent Magnet (CPM) machines are increasingly used in many industrial applications, such as automotive and aerospace applications, wind turbines, medical equipment, robotics, servo drives, and so on. In coreless permanent magnet DC machines, the rotor has a coreless winding structure and due to the absence of an iron core, the permanent magnet plays a significant role in these machines. Also, the shaft’s material can change the flux distribution and is another effective parameter on machine performance. Thus, in this paper, a typical coreless PMDC brushed machine is simulated and the effects of magnetization direction and the amount of the residual flux density of permanent magnet, and also the influence of ferromagnetic and non-ferromagnetic material of the shaft on machine performance, are studied and analyzed through three-dimensional finite element analysis. The results show that using a ferromagnetic shaft with a diametrical magnetized permanent magnet can improve the machine's performance in motor mode.
Magnetic, Electric and insulation materials
Banafsheh Mirtaheri; Hamed Tahanian
Abstract
Permanent Magnets (PMs) are employed in many modern devices, thanks to their unique properties. Electrical machines, i.e., motors and generators, are a major application of PMs, which produce the required magnetic field. When there are severe constraints on the weight and dimensions of the device (e.g. ...
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Permanent Magnets (PMs) are employed in many modern devices, thanks to their unique properties. Electrical machines, i.e., motors and generators, are a major application of PMs, which produce the required magnetic field. When there are severe constraints on the weight and dimensions of the device (e.g. in hybrid electric vehicles or wind turbines), using high-energy PMs would be of crucial importance. Currently, PMs which contain Rare-Earth Elements (REEs), e.g. Sm-Co and Nd-Fe-B, are the most commonly used and the most powerful practical PMs. However, the monopolized supply of the raw materials required for the production of these PMs as well as the recent rise in their global price, have encouraged researchers to investigate some methods for reducing the consumption of REEs or substituting other PMs for those with REEs. This paper studies the state of the art advances in developing PMs with less or no REEs and the corresponding achievements.
Arsalan Hekmati; Iman Sadeghi Mahalli; Mohammad Siamaki
Abstract
In the PMSM, by creating a sinusoidal distribution for conductors at the stator surface, the airgap’s flux density is closer to the sinus form [1]. By replacing the field’s winding with a permanent magnet, the brushes, slip-rings, and copper losses could be removed from synchronous motor. ...
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In the PMSM, by creating a sinusoidal distribution for conductors at the stator surface, the airgap’s flux density is closer to the sinus form [1]. By replacing the field’s winding with a permanent magnet, the brushes, slip-rings, and copper losses could be removed from synchronous motor. The permanent magnet generates motors with permanent excitation. Fig. 1, shows two different ways in which permanent magnets are put into rotor .The following figure shows the ratio of magnetic torque to reluctance torque in synchronous machines. Regarding the mechanism of torque producing, synchronous machines are divided into three distinct groups. The surface-PMSM (SPMSM), in which arc-shaped permanent magnets are embedded on the surface of cylindrical rotor .Such machine is a complete PMSM which produces only magnetic torque. Synchronous reluctance machine (synRM) is a pure reluctance machine shown in Fig. 2. f. The inset SPMSM belongs to SPMSM category in terms of magnet arrangement, however it is a combined reluctance-magnetic motor because of its magnetic saliency. Interior PMSM (IPMSM) in which permanent magnets are buried inside the rotor (Fig. 2. c, d, and e) has magnetic saliency, so it is a hybrid reluctance-magnetic motor which can be considered as a PMSM motor regarding its reluctance torque (region II) or a synRM motor regarding its magnetic torque.
Arsalan Hekmati; iman sadeghi
Abstract
Synchronous speeds in all types of alternating current machines depend on the frequency of the power grid, and performance at higher speeds at steady conditions requires higher frequency feeds. The development of speed control drive technology in recent decades has prompted renewed attention to high-speed ...
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Synchronous speeds in all types of alternating current machines depend on the frequency of the power grid, and performance at higher speeds at steady conditions requires higher frequency feeds. The development of speed control drive technology in recent decades has prompted renewed attention to high-speed engines. Important advantages of using high speed electric motors include higher density (and smaller dimensions) and greater torque generation capability. Also, the use of these motors enables the removal of the gearbox and lubrication system, which reduces maintenance costs. Nowadays, surface-mounted PMSMs are increasingly used for high-speed applications, because of the merits of simple structure and high-strength of the rotor. This paper first discusses the fundamental differences in the configurations of ordinary and high-speed permanent magnet motors, considering their specific characteristics. The specimens and their properties, have been discussed. Finally, the modern applications of high-speed permanent magnet motors have been introduced. also, the main manufacturers of high speed synchronous motors have been presented.
