共查询到20条相似文献,搜索用时 31 毫秒
1.
Tu X. Dessaint L.-A. El Kahel M. Barry A. O. 《Industrial Electronics, IEEE Transactions on》2006,53(6):1818-1828
A synchronous machine internal faults model based on the actual winding arrangement is described in this paper. Based on the winding function approach, the machine inductances are calculated directly from the machine winding distribution, thereby the space harmonics produced by the machine windings are readily taken into account. Moreover, the calculation of the machine inductances is made easier by the use of the machine electrical parameters instead of the geometrical ones. Simulation results for internal faults on a laboratory generator are compared with experimental results to verify the accuracy of the proposed model 相似文献
2.
Research has indicated that the permanent magnet motor drives, which include the permanent magnet synchronous motor (PMSM) and the brushless DC motor (BDCM) could become serious competitors to the induction motor for servo applications. The PMSM has a sinusoidal back EMF and requires sinusoidal stator currents to produce constant torque while the BDCM has a trapezoidal back EMF and requires rectangular stator currents to produce constant torque. The PMSM is very similar to the wound rotor synchronous machine except that the PMSM that is used for servo applications tends not to have any damper windings and excitation is provided by a permanent magnet instead of a field winding. Hence the d , q model of the PMSM can be derived from the well-known model of the synchronous machine with the equations of the damper windings and field current dynamics removed. Because of the nonsinusoidal variation of the mutual inductances between the stator and rotor in the BDCM, it is also shown that no particular advantage exists in transforming the abc equations of the BCDM to the d , q frame. Hence the solution of the original abc equations is proposed for the BDCM 相似文献
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《Industrial Electronics, IEEE Transactions on》2009,56(6):2047-2057
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Pelizari A. Chabu I.E. 《Latin America Transactions, IEEE (Revista IEEE America Latina)》2009,7(2):176-181
The single phase induction motors needs two stator windings to produce rotating magnetic field : one main winding and the other auxiliary winding. The aim of the auxiliary winding is to create the rotating electromagnetic field when the machine is started-up and is afterwards turned off, generally through the centrifugal switch coupled together with the shaft of the machine rotor. The main purpose of this document is to evaluate the influence that the two windings have on the external characteristics of the single phase induction motor . For this purpose , two different kinds of windings were carried out and simulated, with the proposal to obtain some benefits. The main winding and the auxiliary winding were prepared and mounted on a prototype. The simulation was done via software based FEM , to make the extraction and results analysis possible. This results are shown at the end this document. 相似文献
6.
《Mechatronics》2014,24(8):1050-1058
The sidebands around stator currents harmonics as a potential tool for supporting the diagnosis of rotor faults in induction motors are analyzed in this paper. The presence of broken bars introduces high frequency components in the machine currents spectrum in addition to the characteristic sidebands around the fundamental component. These additional components are due to the interaction between, rotor asymmetry and either the voltage harmonics, or winding distribution, or rotor slots. In particular, the components at frequencies near to fifth and seventh harmonics, produced by the interaction between the rotor faults and the harmonics of the spatial distribution of stator windings, are analyzed in this work. A multiple coupled circuit model of the induction motor is used to evaluate the sensitivity of these components for different stator winding configurations, load level, supply voltage conditions, and different number of broken bars. Simulation results showed that a particular analyzed component near to fifth harmonic depends mainly on fifth harmonic of winding distribution, which remains almost constant for most common distributions. Therefore, it is expected that this component should be found in most motors with broken bars. Finally, experimental laboratory results and two industrial cases that validate the analysis are presented. 相似文献
7.
Marouani K. Baghli L. Hadiouche D. Kheloui A. Rezzoug A. 《Industrial Electronics, IEEE Transactions on》2008,55(5):1910-1920
This paper presents a new space vector pulsewidth modulation (SVPWM) technique for the control of a six-phase voltage source inverter (VSI)-fed dual stator induction machines (DSIM). A DSIM is an induction machine which has two sets of three-phase stator windings spatially shifted by 30 electrical degrees and fed by two three-phase VSIs. Despite their advantage of power segmentation, these machines are characterized by large zero sequence harmonic currents, and in particular those of order 6 k plusmn 1, which are due to the mutual cancellation between the two stator windings. The proposed SVPWM scheme, while easy to implement digitally, reduces significantly these extra stator harmonic currents. Experimental results, collected from a 15 kW prototype machine controlled by a digital signal processor, are presented and discussed. 相似文献
8.
This paper describes a digital simulation method for the self-controlled synchronous motor (SCSM) in time domain. A generalized machine model in direct three-phase quantities is used to represent the machine and the fourth-order numerical integration technique of Runge, Kutta, and Gill in [17] is used to solve the machine equations. Performance of the synchronous machine with nonsinusoidal voltages and currents is simulated under both steady-state and transient conditions. The effects of the damper windings and saliency on the torque, and voltage and current waveforms are studied using this digital simulation technique when the machine is operated from a voltage source inverter (VSI) and a current source inverter (CSI). 相似文献
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A novel concept for power factor correction of induction machines is introduced that employs an auxiliary three-phase stator winding together with a pulse-width-modulated (PWM) inverter to supply excitation power to the machine. When the PWM inverter is modeled as an equivalent capacitor, it is shown that two values of capacitance will yield unity power factor at a given operating condition. The effect of machine parameters on the critical value of capacitance is examined. A control algorithm to ensure unity power factor at the terminals of the main stator windings is presented, and its satisfactory operation is verified by means of a detailed analog computer simulation 相似文献
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Hofmann H.F. Sanders S.R. EL-Antably A. 《Industrial Electronics, IEEE Transactions on》2004,51(5):1066-1072
This paper presents a position-sensorless vector torque controller designed to achieve maximum efficiency over a range of power and rotational speed for a synchronous reluctance machine. A model of the synchronous reluctance machine is presented which incorporates both winding and core losses. It is then shown that a stator-flux-oriented control scheme can achieve synchronous operation of the machine without a position sensor at medium and high electrical frequencies. For a given speed and torque, power losses in the machine are shown to be a function of only the stator flux magnitude. As the power losses are a convex function of the stator flux level, the optimal flux value can be found using a one-dimensional optimization algorithm, such as the Method of Sequential Quadratic Interpolations. Optimal flux values for a synchronous reluctance machine are determined using an experimental setup that accurately determines losses in the motor/drive system. Experimental results obtained from the test setup confirm the validity of the controller and the optimization algorithm. 相似文献
12.
A progress report on the program at MIT to demonstrate the feasibility and potentials for the application of superconductors in the rotating field windings of large central station synchronous generators is presented. A brief history of the program and a synopsis of previously reported results are given. The second ex-experimental machine (which will have a rating of about 2 MVA) is described. 相似文献
13.
Shamsi-Nejad M.-A. Nahid-Mobarakeh B. Pierfederici S. Meibody-Tabar F. 《Industrial Electronics, IEEE Transactions on》2008,55(5):1956-1965
In this paper, a new method for filtering the torque pulsations is proposed for double-star permanent magnet synchronous machines under fault conditions. The machine is supplied by two independent electric sources via two voltage source inverters. The proposed method deals with the case where an open-circuit fault occurs. To reduce the torque pulsations, the usual solution consists in supplying only the healthy star winding. Here, we propose to supply not only the healthy winding, but also the two remaining phases of the other star winding by the healthy legs of the faulty inverter. The stator current waveforms can be easily determined to minimize the copper losses while reducing the torque pulsations. Simulation and experimental results confirm the efficiency of the proposed method. 相似文献
14.
J. W. Kolar ÖVE IEEE IEEJ VDE H. Ertl ÖVE R. S. Wieser ÖVE M. Schrödl ÖVE 《e & i Elektrotechnik und Informationstechnik》2000,117(2):134-140
The paper presents an inverter concept for the realization of an induction machine drive with an extremely wide constant power range. The stator winding of the induction machine is split up into two isolated and quasi-bifilar wound three-phase winding systems. The series operation of the two winding sets provides very high torque at low stator frequencies while keeping the machine terminal and the inverter DC link current relatively low. However, due to the high number of turns field weakening is necessary at low frequencies (approximately at 50% of rated speed) already. Nevertheless, with the help of an electronic transition from series to parallel stator winding arrangement the machine flux can be restored to its nominal value as given for rated machine speed. Consequently, the break-down torque is increased by a factor of 4 which gives the basis for a high maximum speed with constant machine power. 相似文献
15.
《Industrial Electronics, IEEE Transactions on》2008,55(12):4238-4251
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Xianrong Chang Cocquempot V. Christophe C. 《Industrial Electronics, IEEE Transactions on》2003,50(3):578-584
This paper presents a new model of asynchronous machines. This model allows one to take into account unbalanced stator situations which can be produced by stator faults like short circuits in windings. A mathematical transformation is defined and applied to the classical abc model equations. All parameters which affect this new model can be known online. This makes the model very useful for control algorithms and fault detection and isolation algorithms. The model is checked by comparing simulation data with actual data obtained from laboratory experiments. 相似文献
17.
Mohapatra K.K. Kanchan R.S. Baiju M.R. Tekwani P.N. Gopakumar K. 《Industrial Electronics, IEEE Transactions on》2005,52(5):1372-1382
Split-phase (six-phase) induction motor stator windings consist of two sets of three phase windings, which are spatially phase separated by 30 electrical degrees. Due to mutual cancellation of the air gap flux for all the 6n/spl plusmn/1 (n=1,3,5...) order harmonic voltages, called zero sequence components, large harmonic currents are generated in the stator phases. Only the 12n/spl plusmn/1 (n=0,1,2,3...)-order harmonic voltage components contribute toward the air gap flux and electromagnetic torque production in the machine. In this paper, a novel scheme is proposed where two six-phase induction motors are connected in series with proper phase sequence so that the zero sequence component voltages of one machine act as torque and flux producing components for the other. Thus, the two six-phase motors can be independently controlled from a single six-phase inverter. A vector control scheme for the dual motor drive is developed and experimentally verified in this paper. 相似文献
18.
This paper investigates the steady-state and dynamic response of an interior permanent magnet (IPM) synchronous machine drive to a single-phase open-circuit fault. This fault results in rotational electromagnetic asymmetry on both the stator and rotor, making it difficult to analyze using classical dq-transformation techniques. This paper presents a new dq synchronous-frame machine model that is capable of handling this highly asymmetrical fault condition, including the effects of q axis magnetic saturation. Fault responses with two alternative post-fault control strategies are investigated: (1) opening all of the inverter switches so that the machine behaves as an uncontrolled generator (UCG), with the two unfaulted phases connected to the inverter DC link via the antiparallel diodes; and (2) shorting the two remaining unfaulted phases together using the inverter switches. Results of this investigation show that the fault response is generally more benign using the UCG control strategy, with significantly lower phase currents and pulsating torque than corresponding values delivered using the phase-shorting strategy. 相似文献
19.
Additional Losses in the Damper Winding of Large Hydrogenerators at Open-Circuit and Load Conditions
Traxler-Samek G. Lugand T. Schwery A. 《Industrial Electronics, IEEE Transactions on》2010,57(1):154-160
Large salient-pole synchronous machines are typically equipped with a damper winding. At steady-state conditions, parasitic voltages are induced in the damper bars which lead to a current flow with associated power losses. This paper describes an analytical algorithm for the calculation of currents and corresponding losses in the damper winding. The presented method is based on an equivalent network of the damper winding containing all the bars of a repetitive section of the machine. The inductances are calculated with an air-gap permeance model. Contrary to similar existing approaches, the induced damper-bar voltages are computed using a numerical integration. This allows more precise results when it comes to higher harmonics. In order to validate the analytical computation, the results are compared with the results of 2-D transient finite-element studies and with a conventional analytical method based on the d-and q -axis equivalent circuits of the machine. 相似文献
20.
A power control system for a doubly fed wound rotor induction generator has been developed. This power control system applies a control method using a rotating reference frame fixed on the gap flux of the generator, and can control active and reactive power independently and stably. The characteristics of the control system have been proved by experiment. Harmonic currents fed to the rotor windings are transmitted to the stator winding changing its frequency. The transmitting characteristics of the harmonic currents have been analyzed and verified by experiments 相似文献