共查询到20条相似文献,搜索用时 46 毫秒
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《Industry Applications, IEEE Transactions on》2009,45(6):1947-1953
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ADDITIONAL LOSSES IN SOLID-ROTOR SALIENT-POLE SYNCHRONOUS MACHINES ASSOCIATED WITH STATIC CONVERTORS
A. A. ABDEL-RAZEK 《电力部件与系统》2013,41(2):101-111
Abstract In solid-rotor synchronous machines associated with static converters, the harmonics generated by the operation of converters result in additional losses in the different parts of the machine. These losses are investigated in this paper. The rotor harmonic currents are determined, the machine equivalent-circuits are derived, and the losses are obtained for the general case of salient-pole machines. The results show that the additional losses are considerable and that constructing the solid-rotor machines with simple damper cages and laminated pole faces has the most prominent effect on reducing these losses. 相似文献
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《Industry Applications, IEEE Transactions on》2009,45(2):720-728
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NADY BOULES 《电力部件与系统》2013,41(6):527-539
ABSTRACT This paper presents an analytical method for determining the harmonic content in the flux pattern of permanent magnet synchronous machines due to the slotting of the stator. The analysis based on a rotor construction with magnets radially magnetized and a retaining ring to support them against the centrifugal forces. Expressions for the eddy current losses in the magnets and their retaining ring are derived in terms of the machine dimensions and the physical properties of magnets and ring. The accuracy of the method is examined by comparison with numerical flux calculations using finite element method. The impact of some physical quantities like machine speed and magnet conductivity on the slot harmonics losses is examined aiming to exhibit the role of the magnet retaining ring in contributing to these losses 相似文献
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This paper presents a refined design of a high-speed synchronous reluctance machine with minimized eddy-current losses in the rotor. Design criteria are the ability of the rotor to withstand high speeds, ability to operate in vacuum, negligible zero-torque spinning losses, high reliability, high efficiency, and low manufacturing cost. The rotor of the synchronous reluctance machine consists of bonded sections of ferromagnetic and nonmagnetic steels. Finite-element code, incorporating rotor rotation, has been developed in MATLAB that calculates steady-state eddy currents (and losses) in the rotor. A stator iron and stator winding have been designed to minimize rotor losses, and two such prototype machines have been fabricated. Experimental results show an efficiency of 91% at a 10 kW 10000 r/min operating point, and rotor losses less than 0.5% of input power 相似文献
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设计了一种实心转子永磁同步电机,并提出了适用于该类电机的场路耦合运动时步有限元分析方法,解决了实心转子电机中转子电阻难以准确计算的问题。该方法考虑了转子电阻随转差的变化,给出了外电路与电磁场耦合的时步有限元分析方法,采用运动气隙边界法解决转子运动问题,与机械运动方程相结合,对电机的瞬态过程进行仿真。应用上述方法对自行设计的22kW实心转子永磁同步电机的性能进行分析,空载反电动势和起动转矩的计算结果与样机的实验结果吻合较好,表明本文提出的方法准确有效,并可用于其他类型的实心转子电机的性能分析。 相似文献
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《Electric Power Systems Research》1996,37(1):19-28
An analytical model of the cross-magnetizing effect in saturated synchronous machines is proposed in which a second-order polynomial function is used to approximate the magnetization curve. The d- and q-axis magnetizing flux linkages are found as closed-form nonlinear functions of the d- and q-axis magnetizing currents. The magnetic reciprocity appears in this analytical model and can be applied to the simulation of saturated synchronous machines. The machine equations can be linearized to give the small-signal model around an operating point, whose associated eigenvalues can be computed. The discrepancy between machine performances with and without cross-magnetization is manifest at heavy loads due to increased saturation. 相似文献
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分层阻抗理论是研究实心转子感应电机的一种有效方法,表面磁钢永磁同步电机转子结构与复合转子电机具有相似性,文中采用分层阻抗理论对表面磁钢永磁同步电机转子参数分析并讨论 相似文献
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E. ANDRESEN 《电力部件与系统》2013,41(3):219-231
ABSTRACT Interference synchronous machines operate at different speeds of the fundamental air gap field and of the rotor, because the fundamental permeance wave is produced by interference of open stator and rotor slots the numbers of which being slightly different. In the literature different names are used for this remarkable electrical machine (“Synchronous inductor motor”, “Vernier reluctance motor”). Interference synchronous machines are used as homopolar frequency generators with an axial field coil, as continuous running reluctance motors and as single- or double, - stack step motors with an axial permanent magnet. In this paper the field of the interference synchronous machine is analysed by field wave theory. Speed,phase angle and length of the largest field waves reveal how synchronous and cogging torques are produced. Voltage and torque equations are derived by axis theory from the simplest model that is possible with five rotor teeth. The theory is applied on a fifty rotor teeth double-stack step motor. The inductances are determined by a difference method field calculation. The torque of the motor is then calculated and compared with measured values. 相似文献
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Pierre Köhring 《Electrical Engineering (Archiv fur Elektrotechnik)》2009,91(4-5):263-272
The transient skin effect is solved for the rectangular open and semi closed slots containing a massive conductor. The solution is applied to the Joule losses and to the analytical calculation of the air gap torque and the stator currents of the induction machine exposed to the three-phase short circuit. The calculation of the Joule power losses under transient conditions has been accomplished, especially, for induction machines of the middle- and high-power range. This becomes important in dynamically controlled induction machines, especially when torque cycles of approximately 100 ms or less occur. Never before have the copper losses been evaluated completely under these transient conditions. For the calculation of the losses, the direct proportionality of the losses between torque and rotor bar current can be used. Furthermore, the results of the transient skin effect can find application in the operational behavior of the induction machine. The consideration of the transient skin effect of the rotor is necessary for calculating currents and torques. Until now, state of the art has only provided an analytical solving of the skin effect free model. Aiming to apply the given rotor geometry, this paper derives an approach which includes the transient skin effect, applying it on the three-phase short circuit of the idle running induction machine. 相似文献
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ABSTRACT A comprehensive study of the parameter sensitivity on both the synchronous and asynchronous performances of permanent magnet machines is presented. Based on the 2-axis theory for permanent magnet motor, performance equations are derived In terms of normalized machine parameters. Such an analysis can be used successfully in design optimization of permanent magnet machines. A normalized power equation for evaluating the steady-state stability limits of such type of motor is also given. Simulation results obtained are confirmed with experimental results using a number of different rotor designs. Useful conclusions have been provided, which are considered to be a good aid for designing any permanent magnet motor. 相似文献
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针对传统内置式永磁同步电动机(PMSM)反电动势谐波含量高,转矩脉动大等缺点,提出一种高功率密度电动汽车用不等气隙永磁同步电机(UG-PMSM),通过气隙的不均匀特性,改善空载反电动势正弦特性.建立了UG-PMSM电机功率尺寸方程,利用二维有限元分析法,分析了空载永磁磁链、空载感应电动势、输出转矩、转矩脉动、齿槽转矩等静态特性,计算了UG-PMSM电感特性,在此基础上,研究了UG-PMSM过载能力与弱磁扩速范围.仿真分析结果验证了UG-PMSM高功率密度、高转矩密度、低转矩脉动等优点,适合应用于电动汽车驱动系统中. 相似文献
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Abstract The design philosophy and the optimization procedure used in the design of the superconducting generator are outlined and the effect of different parameters on the overall machine size and power density is examined. The effects of superconductor capability, environmental shield, type of rotor construction on the design of the machine are investigated. It is shown that the present day superconductors offer as much magnetic field generating capability as can be profitably used in synchronous machines and it is also shown that even in the “iron-free” or “air-core” superconducting machine, the design is dominated by the iron environmental shield. 相似文献
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为改善高速永磁电机磁场调节困难的问题,提出一种新型混合励磁电机,转子上既有永磁极又有铁心极,磁路呈现典型的径向、周向和轴向三维特性,难以直接用解析法求取电感参数。根据新型混合励磁电机的磁路特点,提出一种等效分析方法,将复杂磁路的混合励磁电机等效为三种二维磁路电机轴向并列叠加。为了提高新型混合励磁电机电磁设计与性能分析的效率,推导了其数学模型与电感参数表达式。对一台10 k W混合励磁原理样机进行了有限元分析与实验研究,结果验证了所提数学模型与等效分析方法的正确性,为该类电机的设计和优化提供了理论支撑。 相似文献
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Brushless doubly fed induction machines (BDFIMs) have been extensively researched over because of the possibility of using a partially rated inverter in many applications with limited speed variations. However, the special cage rotor construction and substantial rotor losses is one of the key deficiencies of these machines. A similar and extremely interesting machine, the brushless doubly fed reluctance machine (BDFRM), has been largely ignored in comparison. This was mainly due to the fact that reluctance rotor designs were not capable of generating saliency ratios large enough to make the BDFRM competitive with other machines. However, developments in reluctance rotors, spurred on by research into synchronous reluctance machines, have resulted in high-saliency-ratio cageless rotors that are economical to build. This, together with the promise of higher efficiency and simpler control compared to the BDFIM, means that further investigation of the BDFRM is warranted. This paper presents a comparative theoretical analysis and aspects of practical implementation of the important control strategies and associated machine performance/inverter size tradeoffs for the BDFRM in the light of its most likely applications-large-pump-type adjustable-speed drives and variable-speed constant-frequency wind power generation systems. 相似文献
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Axial displacement of the stator in a synchronous machine gives rise to axial magnetic field both at the ends and deep inside the stator. The axial magnetic field causes losses. This article contains results from two studies with an axially displaced stator. In the first study, axial magnetic leakage fields in the ends of a small synchronous generator at load and no load were measured and simulated. In the second study, axial force and iron losses at no load were calculated with non-linear materials and a three-dimensional, time-stepped finite element method. For some machines with vertical shafts, the sum of iron losses and thrust bearing losses can be reduced if the rotor is lowered or the stator raised, whichever is best. 相似文献