طراحي، تحليل و ساخت يك ماشين سنكرون رلوكتانسي تقويت شده با آهنربا بر مبناي سيم‌پيچي‌هاي متمركز

Design, Analysis an‎d Prototyping of a PM-Assisted Synchronous Reluctance Machine Based on Concentrated Windings

مهندسي برق

Synchronous reluctance machines are sort of AC machines that are simpler an‎d cheaper than other types of AC motors. However, these motors inherently have a low power factor an‎d lower power an‎d torque density compared to permanent-magnet motors. To overcome these disadvantages, the use of a small amount of permanent-magnet material in such motors can be effective, an‎d this addition of magnets led to the emergence of PM-assisted synchronous reluctance machines, which are used in many applications instead of the pure synchronous reluctance motors. On the other han‎d, fractional-slot concentrated-windings (FSCWs) due to their higher slot fill factor, shorter end-winding length, low copper losses, high efficiency, simplicity an‎d low manufacturing cost, have always attracted the attention of researchers. Because of low rate of harvesting of reluctance torque, these windings have not often been successfully used in the construction of this type of motors. In this thesis, in order to increase the rate of harvesting of reluctance torque in these machines- which are equipped with FSCWs- by the means of stator slot shifting concept, a new type of fractional-slot concentrated-windings is introduced that simultaneously provides the capabilities of general distributed- an‎d fractional-slot concentrated-windings. As an example, a 36-slot/10-pole fractional slot winding with two slot shifts is obtained from a 12-slot/10-pole winding, which contains much fewer MMF harmonics, such that the THD percentage of the MMF harmonics produced by the stator decreased from 89% in the 12/10 to 19% in the 36/10 arrangement. These new windings, including 3-phase an‎d 5-phase windings, are introduced for the first time in this thesis an‎d their winding’s layouts are exhibited here. These new windings include various combinations of pole an‎d slot numbers, an‎d while the MMF waveform produced by the stator is modified an‎d its harmonics are greatly reduced, they retain the major advantages of fractional slot windings, including short end-winding length an‎d low copper losses. Based on these proposed winding configurations, one of the new 3-phase windings is selec‎ted, an‎d a 180W prototype machine is designed an‎d built as a case study; an‎d analytical results, the finite element analysis, an‎d experimental tests are conducted to validate the machineʹs characteristics. At the end, in order to improve the performance of the primary pure reluctance machine, magnets are inser‎ted in the rotor flux barriers, an‎d the results of simulations an‎d practical tests show that not only the use of magnets improve the machineʹs power factor from 0.48 to 0.83, but the average torque produced by the machine also increases from 2.23 to 2.89 Nm.

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