transverse flux and flux reversal permanent magnet generator systems

... Fig 1.3, and Interior Permanent Magnet (IPM) motors in which the permanent magnets are hidden inside the rotor, Fig 1.4 The surface-mounted PMSM (Fig 1.3 a) in EPM motors can have magnets magnetized ... understand the characteristics of permanent magnet materials used in electric motors for excitation 1.3 Characteristics of PM Materials The development of permanent magnets with high flux density and ... location of the magnets on the rotor, typical PMSMs can be divided into two kinds: Exterior Permanent Magnet (EPM) motors which have the permanent magnets directly facing to the air gap and stator...

Ngày tải lên: 15/09/2015, 22:06

... the magnet, Rr the inner radius of the rotor yoke, Mn and Nn are the Fourier coefficients of the magnetization of the permanent magnets, r is the relative permeability of the permanent magnet, and ... extremely low level Permanent magnet (PM) brushless dc motors are adopted in hard disk drives Modern permanent magnets possess high residual magnetization and high coercivity Thus, strong flux density ... requirements for the electromagnetic forces are extremely stringent Electromagnetic forces such as the cogging torque and unbalanced magnetic pull (UMP) generated in the permanent magnet spindles are...

Ngày tải lên: 15/09/2015, 22:03

... fault On the other hand, Khoobroo and Fahimi [23] use a field reconstruction method to study SUMP in a Permanent Magnet Synchronous Motor (PMSM) Bi and his colleagues [24] analyzed and calculated ... electromagnetic (EM) and mechanical ones The former could be induced by the unreasonable EM structure, the unreasonable drive modes and the quality of the EM components e.g winding, magnet, and ... the torque ripple and unbalance-magnetic-pull in the motor operation The latter could be induced by the quality of bearings, magnets, shaft, rotor and stator yoke of the motor and by problems in...

Ngày tải lên: 16/09/2015, 12:06

... efficiency of electromagnetic and permanent magnet excitation become so close such that the price of permanent magnet material may not be justified 5 However, price of rare earth permanent magnet keeps ... dt (2.4) where Vd and Vq are the d- and q-axis voltages Id and Iq are the d- and q-axis currents λd and λq are the d- and q-axis flux linkages R is the armature resistance The magnetic field in ... Figures 1.1 Magnetic characteristics of the main class of permanent magnets [2] 1.2 Evolution of the magnetic material during the 20th century [2] 1.3 Partial demagnetization of a permanent magnet...

Ngày tải lên: 04/10/2015, 15:45

... (non salient PMSM), and the Back Electromagnetic Force (BEMF) is sinusoidal The air gap flux is equal to the sum of the rotor’s flux linkage, which is generated by the permanent magnets plus the ... CAUTION: During field weakening of a Surface Permanent Magnet (SPM) type of PMSM, mechanical damage of the rotor and the demagnetization of the permanent magnets is possible if careful measures are ... headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India The Company’s quality system processes and procedures...

Ngày tải lên: 11/01/2016, 17:05

... Electronics and Variable-Speed Drives C Marchand, A Razek, "Electromagnetic Modelling to Optimise Low Speed and Position Control in Servo Motor", I id c t Intamtianal Workshop on Electric and Magnetic ... ib and i, and the ideal currents i, rd, nf and i, nf (figure 6b) ib voltage during the s W y state The "dq" frame is better than " a h " frame It need more complex implementation, but the band ... control laws witch allow best dynamic and steady state behaviours, such as vector controls in "a@ or "dq" frames References T.J.E Miller, "Brushless Permanent magnet and Reluctance Motor Drives", Clarendon...

Ngày tải lên: 03/01/2014, 19:50

... excited permanent- magnet motor - design and performance Third International Conference on Electrical Machines and Drives, IEE, London, UK, Nov 16th-18th 1987, pp 246249 LOW, T.S Permanent- magnet ... when the motor flux distribution differs significantly from the ideal sinusoid and it is well-known that nonsinusoidal flux dis- processing of signals such as position, velocity and current, which ... reliable and accurate instantaneous torque feedback is examined The performances of the proposed controller design and torque feedback technique are investigated in computer simulation studies and...

Ngày tải lên: 03/01/2014, 19:52

... attraction field of #3 magnet and the whole process is repeat again and again untill it reaches the end of #9 magnet, Now if # and #9 magnet is not Slanted or curved from #2 and #4 magnet then there ... VHS Video of this model and experiment Model#A Video $19.95 #8 and #9 Magnets are slanted or curved downward away from carriage Page Permanent Magnet Motor Files #376 #2 and #4 is glued or silicone ... attraction) Then # magnet is placed just right where it will attract to the same magnet that #2 is stuck in and will pull and push the #2 out of the #1 magnets resistance stage and push it right...

Ngày tải lên: 19/01/2014, 20:20

... this is done to Chapter 14 4.2 VOLTAGE AND TORQUE EQUATIONS IN MACHINE VARIABLES A two-pole, permanent- magnet ac machine, which is also called a permanent- magnet synchronous machine, is depicted ... are neglected since the permanent magnets are typically relatively poor electrical conductors, and the eddy currents that flow in the nonmagnetic materials securing the magnets are small Hence, ... the magnetic field established by the current following in the armature windings is stationary and orthogonal to the stationary magnetic field established by the field winding or the permanent magnet...

Ngày tải lên: 16/02/2014, 18:46

... have a logical output when they are under a south magnetic pole and a logic when they are under a north magnetic pole of the permanent magnet, and are arranged on the stator of the PMAM as illustrated ... variable currents), the q- and r∗ r∗ d-axis voltage commands ( vqs and vds ) are determined The q- and d-axis voltage ∗ command is then converted to an abc variable voltage command vabcs , which is ... emf, and a PI control loop Assuming that the actual q- and d-axis voltages are equal to the commanded q- and d-axis voltages, it can be shown that the transfer function between the commanded and...

Ngày tải lên: 16/02/2014, 18:54

... reaction flux to the permanent magnet flux linkage [6]; If E is large and the coercivity of the magnet is not enough, then the permanent magnet demagnetization may create a serious problem and the magnet ... values of the demagnetizing coefficient are about 0.8 In some cases, the permanent magnet is demagnetized irreversibly by the flux- weakening control VI DEMAGNETIZATION OF PERMANENT MAGNET If the ... The current commands are decided by the torque command and the detected speed using the lookup table The commands iC; and i; are transformed to the phase current commands i; and i using the rotor...

Ngày tải lên: 08/03/2014, 22:01

... Orthopaedic Surgery and Research 2010, 5:23 http://www.josr-online.com/content/5/1/23 Page of 1)Comparison of axial and torsional stiffness characteristics of TSF with half pins and transverse wires ... diameter (155 mm and 180 mm) and wire or pin divergence angle (45 degrees, 60 degrees, 75 degrees and 90 degrees) This resulted in 24 constructs based on ring sizes, divergence angles and configurations ... using transverse wires Khurana et al Journal of Orthopaedic Surgery and Research 2010, 5:23 http://www.josr-online.com/content/5/1/23 Page of (half pins, ring fixed with transverse wires and rings...

Ngày tải lên: 20/06/2014, 04:20

... impurities and corrosion products concentration and deposition and their removing from the CANDU steam generators is a very active field and both the experimental works and the understanding of ... monitoring and mitigation of these degradations the performances of the steam generators decrease and determine direct and indirect losses The replacement of the steam generator is very expensive and ... for WWER Steam Generators Inspection 145 Valentin Uchanin and Vladimir Najda Chapter Detection of Magnetic Phase in the Steam Generator Tubes of NPP 165 Duck-Gun Park, Kwon-Sang Ryu and Derac Son...

Ngày tải lên: 29/06/2014, 14:20

... Example Energy and Coenergy Energy and coenergy in singly excited systems Energy and coenergy in doubly excited systems Coenergy in the presence of a permanent magnet Force, Torque, and Power Basic ... Torque Motor Action Magnet Poles and Motor Phases Poles, Slots, and Teeth Mechanical and Electrical Measures Motor Size Conclusion 1 10 11 12 Chapter Magnetic Modeling 13 Magnetic Circuit Concepts ... Concepts Basic relationships Magnetic field sources Air gap modeling Slot modeling Example Magnetic Materials Permeability Ferromagnetic materials Core loss Permanent magnets PM magnetic circuit model...

Ngày tải lên: 02/07/2014, 08:20

... developed The properties of ferromagnetic and permanent- magnet materials were discussed A magnetic circuit model of a permanent magnet was introduced and the concept of flux concentration was illustrated ... rectangular magnet and its magnetic circuit 36 Chapter T sumes that the physical magnet is uniformly magnetized over its cross section and is magnetized in its preferred direction of magnetization ... fundamental magnetic field concepts, the concepts of Magnetic Modeling 39 permeance, reluctance, flux, and mmf were developed Permeance models for blocks of magnetic material, air gaps, and slotted magnetic...

Ngày tải lên: 02/07/2014, 08:20

... gapflux andflux density are given by (4.11) and (4.12), respectively, and can be evaluated using thefixed and known geometric parameters given above As discussed in Chap 4, the flux from each magnet ... the rotor bearings Magnet shaping Though not apparent from (5.12), magnet shape and magnet- to -magnet leakage flux has a significant effect on cogging torque (Prina, 1990; Li and Slemon, 1988; ... the rotor magnets and the slots and poles of the stator, i.e., the stator saliency From (3.24) and (4.39), cogging torque is given by cog % de (5.12) where g is the air gap flux and R is the...

Ngày tải lên: 02/07/2014, 08:20

... Skew factor Magnet fraction Flux concentration factor Permeance coefficient Magnet leakage factor Effective air gap for Carter coefficient Air gap area Air gap flux density Air gap flux Back iron ... as Leonhard (1985), and Murphy and Turnbull (1988) With this intuitive understanding, more complex drive schemes are readily understood Two-Phase Motors Until now, torque and back emf expressions ... Fig 7.3, the back emf and current have the same sign at the turn-off points Thus, by (7.4), the Phase Current K 2N 3K Sjand S4 Current e e S 2and S Current Figure 7.8 Phase and switch currents for...

Ngày tải lên: 02/07/2014, 08:20

... magnet) Magnet aspect ratio, 67, 68 Magnetic circuit concepts, 14 Magnet fraction, 66, 141 Magnet leakage factor, 67, 142 Magnet leakage flux, 66 Magnet shaping, 120 Magnetomotive force (mmf), definition ... TS 0) (OE OJm P P Appendix B Common Units and Equivalents Property SI unit Magnetic flux weber (Wb) Flux density tesla (T) Magnetomotive force (mmf) Magnetic field intensity Permeability of free ... authors in day long short courses The basics of magnetic circuit modeling are covered A very good discussion of permanent magnets and magnetizing techniques and fixtures is presented Some equations...

Ngày tải lên: 02/07/2014, 08:20

... 4, the air gap flux and the slot leakage flux both contribute to shoe saturation Here the air gap flux density Bg enters the tooth-shoe face from the air gap and the slot leakageflux crosses from ... of the magnet flux density crossing the air gap The low recoil permeability and long relative length of the PM make Ba small Depending upon the relative position of the coil and PM, the magnet ... force is easy to understand by considering Fig 4.27 In this figure, the rotor magnet is aligned with a maximum amount of stator teeth and the reluctance seen by the magnet flux is minimized, giving...

Ngày tải lên: 02/07/2014, 08:20