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1.
The results of a study on the effect of toothless stator design on the dynamic performance characteristics of high speed permanent magnet generator-load systems are presented. This study is based on the use of magnetic field solutions and state space models which account for saturation due to magnetic material nonlinearities and space harmonics due to machine geometry. Two particular stator designs, a toothless stator and a conventional type stator (with iron teeth), are considered in this study when feeding AC and DC rectified loads. Based on this study, it is demonstrated that the toothless design for this class of PM generators could result in lower levels of harmonics in the various machine voltages and currents waveforms as well as the power delivered to the loads. In addition, some design modifications are discussed to boost the output power level of the toothless machine which are inherently lower than the conventional machine due to the larger effective airgap that exists in the toothless design 相似文献
2.
Arkadan A.A. Demerdash N.A. Vaidya J.G. Shah M.J. 《Energy Conversion, IEEE Transaction on》1988,3(4):880-889
A computer-aided method for determining the impact of load on winding inductances and other machine parameters of permanent magnet generators with multiple damping circuits is presented. The method is general in nature so that it can be applied to detailed computer-aided design processes of permanent magnet generator systems. The method is based on use of the abc frame of reference for development of the necessary state equations 相似文献
3.
文章分析了小型风电机组用的永磁同步发电机的电磁设计特点,并与其他普通永磁电机区别,详细介绍了永磁同步发电机各个电磁参数的特点以及对发电机性能的影响。重点介绍永磁同步发电机定子、转子设计的特点,对不同的极数与槽数的配合进行对比分析,总结降低齿槽转矩的规律。 相似文献
4.
The evolution, design and test results of a novel permanent magnet generator for use in direct‐drive wind turbines are presented. This generator topology is based on steel C‐core modules (which make up the rotor) and an air‐cored stator winding. This topology allows a reduction in structural mass for large diameter generators, which can lead to lightweight generators. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
5.
This paper investigates the possible site matching of the direct-drive wind turbine concepts based on the electromagnetic design optimization of permanent magnet (PM) generator systems. Firstly, the analytical models of a three-phase radial-flux PM generator with a back-to-back power converter are presented. The optimum design models of direct-drive PM wind generation system are developed with an improved genetic algorithm, and a 500-kW direct-drive PM generator for the minimal generator active material cost is compared to demonstrate the effectiveness of the design optimization. Forty-five PM generator systems, the combinations of five rated rotor speeds in the range of 10–30 rpm and nine power ratings from 100 kW to 10 MW, are optimally designed, respectively. The optimum results are compared graphically in terms of the generator design indexes. Next, according to the design principle of the maximum wind energy capture, the rotor diameter and the rated wind speed of a direct-drive wind turbine with the optimum PM generator are determined. The annual energy output (AEO) is also presented using the Weibull density function. Finally, the maximum AEO per cost (AEOPC) of the optimized wind generator systems is evaluated at eight potential sites with annual mean wind speeds in the range of 3–10 m/s, respectively. These results have shown the suitable designs for the optimum site matching of the investigated PM generator systems. 相似文献
6.
The direct‐drive radial flux synchronous generator is considered as the modern wind turbine drive train. Both the electrically (e.g., Enercon) and permanent magnet (PM; e.g., Siemens) excited direct‐drive generators are gaining popularity on the market today. Compared with the matured geared counterpart, the electrically excited direct‐drive generator is heavier and more expensive but more reliable per unit capacity. The PM‐excited generator is expensive, is simpler in electromechanical design, has a high power‐to‐weight ratio, and yields a higher energy conversion efficiency than its electrically excited equivalent. The PM generator technology has the potential to yield the highest energy‐to‐cost ratio. However, standardization of this direct‐drive generator parts/subassemblies may overcome the existing cost barrier. Most current literature focuses on PM generator wind turbine technology, specifically on generator energy conversion optimization, and the scalability of technologies to capacities in access of 5 MW. Strangely, PM generator's mass and cost reductions through optimized structural design incorporating manufacturing, transportation, and installation constraints are less studied. This paper solely focuses on the mechanical and structural design aspects of large radial flux synchronous PM generators specific to direct‐drive wind turbines. Generator topologies such as the common iron‐cored and unconventional air‐cored generator are discussed. However, design considerations specific to the iron‐cored generator topology are studied. The design considerations investigated involve the geometries and the configurations of rotor/stator active and inactive structures, the interfaces, and the conductor/PM mounting methods. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
7.
A direct driven permanent magnet (PM) synchronous generator has been designed and constructed and results from the first experimental tests are presented. The generator has been designed using the finite element method (FEM) and dynamic simulations have been performed to study the generator. The simulations are performed by using an electromagnetic model, which is described by a combined field and circuit equation model and is solved in a finite element environment. The stator winding of the generator consists of circular cables and the rotor has surface mounted, arched PMs. A complete experimental setup has been constructed consisting of a motor, a frequency converter, a gearbox and electrical loads. Oscilloscopes are used to measure the voltage and the current for each phase. Measurements have been performed for both full load and no load at rated speed. The harmonic content of the voltage is analyzed and compared to results from simulations. Furthermore, the generated electric power has been calculated from knowing the voltage and current and is compared to the simulated power. The agreement between experimental results and results from simulations based on finite element calculations is very high, especially considering harmonics. Several sources of error are suggested that could cause the small differences between the simulated results and the measured data for the constructed generator. 相似文献
8.
A study for the enhancement of effective flux of PM machines using flux guides is presented. An intrinsic demagnetization curve that considers the leakage flux is introduced. On the basis of a higher effective flux the stator winding can be more compact; consequently, a lighter stator and a higher efficiency permanent magnet (PM) machine can be obtained 相似文献
9.
针对山地风电场大型永磁同步风电机组发电机定子温度的变化特点及传热过程进行分析,提出一种基于风电机组SCADA数据的发电机定子温度建模方法。首先,分析风电机组在实际运行过程中定子温度的变化情况;然后,根据永磁同步发电机内部的传热过程,对发电机定子温度建模;最后,采用风电机组正常运行时的SCADA数据求解模型参数。实例分析表明,风电机组状态正常时,定子温度估计的平均误差绝对值为0.59 ℃,模型精度较高;风电机组状态异常时,模型温度估计的平均误差绝对值为5.17 ℃,精度显著降低。 相似文献
10.
In permanent magnet (PM) synchronous machines, iron losses form a larger portion of the total losses than in induction machines. This is partly due to the elimination of significant rotor loss in PM machines and partly due to the nonsinusoidal flux density waveforms in the stator core of PM machines. Therefore, minimization of iron losses is of particular importance in PM motor design. This paper considers the minimizing of iron losses of PM synchronous machines through the proper design of magnets and slots, and through the choice of the number of poles. Both time-stepped finite element method (FEM) and the iron loss model from a previous study are used in this paper to draw the conclusions. 相似文献
11.
12.
《Energy Conversion, IEEE Transaction on》2009,24(1):77-81
13.
《Energy Conversion, IEEE Transaction on》2008,23(3):717-726
14.
Control-based reduction of pulsating torque for PMAC machines 总被引:1,自引:0,他引:1
Grcar B. Cafuta P. Stumberger G. Stankovic A.M. 《Energy Conversion, IEEE Transaction on》2002,17(2):169-175
Control methods in torque pulsating reduction for surface-mounted permanent magnet motors are discussed in this paper. The pulsating torque is a consequence of the nonsinusoidal flux-density distribution caused by the interaction of the rotor's permanent magnets with the changing stator reluctance. The proposed control method is estimator based. To assure parameter convergence, Lyapunov's direct method is used in estimator design for the flux Fourier's coefficients. A novel nonlinear torque controller based on flux/torque estimate is introduced to reduce the influence of the flux harmonics. The influence of the cogging torque is considerably reduced at lower motor speed using the internal model principle and adaptive feedforward compensation technique. The overall control scheme and experimental results are also presented 相似文献
15.
采用有限元法对大功率永磁直驱风力发电机定子三维瞬态温度场进行计算,得到了电机定子温度场。对发电机进行了型式试验,测试结果与计算的稳态结果较为接近,验证了计算的准确性。结果表明,电机在额定工况下,温升稳定后端部绕组温度高于中间绕组,最高温度点在背风侧的端部绕组,最高温度与平均温度相差16℃左右。将实际风场的风资源数据作为外界条件,对永磁直驱发电机一定时间跨度的瞬态温度进行计算,结果与SCADA系统采集的风力发电机运行数据较为接近,为绝缘系统设计和电机的优化提供了参考。 相似文献
16.
This paper presents an axial flux permanent magnet synchronous machine (PMSM) with a disk rotor between two stators, which are wound in a tooth-coil technology (a concentrate winding type with subunitary number of slots/pole/phase). This type of winding facilitates the magnetizing inductor function of stator coils. A potential magnetizing system can be envisioned by taking into account that the coil span and the slot pitch are practically identical, the number of tooth-coils and poles are almost the same, and that there are two rotor poles between four tooth-coils (two adjacent tooth-coils on each stator). Thus, a special magnetizing inductor is not required in order to magnetize, pair by pair, the permanent magnet (PM) rotor poles. The number of tooth-coils exceeds the number of rotor poles by one (Ns = 2p + 1). Some aspects of the average performance obtained in both modes of operation-machine and magnetizing inductor-are highlighted by digital simulation. A scale-down demonstrating model also confirmed the feasibility of the magnetizing inductor function of the stator. 相似文献
17.
Yoon-Ho Kim Yoon-Sang Kook 《Energy Conversion, IEEE Transaction on》1999,14(4):868-873
An extended Kalman filter (EKF) based approach for position sensor elimination in interior permanent magnet synchronous motor (IPMSM) drives is presented in this paper. The EKF is capable of estimating system parameters and state variables for the IPMSM by eliminating virtually all influences of structural noises in the vector control scheme. This paper presents a design method of a reduced-order EKF. Position and angular speed of the rotor are obtained through the reduced-order EKF only by measuring stator currents. Also, due to an angle modification scheme with error tracking, the sensorless drive system is robust to parameter variations. Simulation and experimental results are provided to verify the proposed approach based on the reduced-order EKF 相似文献
18.
Nihat Öztürk Adem Dalcalı Emre Çelik Selçuk Sakar 《International Journal of Hydrogen Energy》2017,42(28):17593-17600
In this study, design and optimization of a surface-mounted permanent magnet synchronous generator (PMSG) have been carried out for use in low power wind turbines. In the successive optimization steps based upon the parametric solution method, design parameters of skew, pole embrace, and pole arc offset are chosen to be optimized so that the cogging torque is reduced. Cogging torque is a type of torque ripple coming from the machine design and causes undesired vibration and acoustic noise during the operation of machine. Moreover, although the effect of cogging torque in high power surface-mounted PMSGs is not sensible, it becomes important in low power applications to maintain good dynamical behavior. Analytical and finite element analysis (FEA) are conducted after obtaining the magnet structure that provides minimum cogging torque. Electrical and electromagnetic distributions are presented according to the changes in the corresponding design parameters. While the cogging torque in the initial design is 522.7 mNm, it has been reduced to 49.1 mNm in the optimized generator, which in turn means an improvement of about 90%. The generator under consideration has the specifications of 2.5 kW, 120 V, 14-pole with an inner type-rotor. 相似文献
19.
Jiabin Wang West M. Howe D. La Parra H.Z.-D. Arshad W.M. 《Energy Conversion, IEEE Transaction on》2007,22(2):299-306
This paper discusses issues that are pertinent to the design of a linear permanent magnet generator for application in a free-piston energy converter. To achieve the required high power density, high efficiency, and low moving mass, a tubular machine equipped with a modular stator winding and a quasi-Halbach magnetized armature is employed. It is shown that the machine design can be optimized with respect to three key dimensional ratios while satisfying other performance requirements. It is also shown that, when the generator is interfaced to an electrical system via a power electronic converter, both the converter volt-amps rating and the converter loss should be taken into account when optimizing the machine design. The performance of such a tubular generator is demonstrated by measurements on a 10-pole/9-slot prototype machine. 相似文献
20.
Meshgin-Kelk H. Milimonfared J. Toliyat H.A. 《Energy Conversion, IEEE Transaction on》2003,18(2):187-193
In this paper, a new comprehensive method for the calculation of inductance coefficients of squirrel cage induction machine based on combined winding function approach (WFA) and magnetic equivalent circuit (MEC) is presented. By taking into account machine geometry, rotor skewing, stator and rotor slots effects and type of windings connection, this method is able to model most of the important features of an induction machine. The effects of each machine parameter on the inductance coefficients are verified. Also, effects of several rotor asymmetries on these inductances are shown. Simulation results are verified by more elaborate nonlinear finite element model and finally with experimental results. 相似文献