Induction Motor Stator Slot Design

The shape of the bars is chosen to belong to NEMA’s class A design specification. The speed of operation of the main induction motor "I is thereafter controlled by varying the excitation of the direct-current generator 46, which controls the amount of power which is two direct-current machinm 48 and 54, thus controlling the amount of power which is derived from the sliprings 25, of the main induction motor l0, and returned to the line by the synchronous generator 58, thereby controlling the slip or the induction motor Ill.Then, with the aid of FEM, the results from six simulated induction motors with different rotor slot numbers will be shown and discussed.

Stator frequency, number of rotor slots, slip, type of ec-. Why do open slots are .

Aluminium rotor bars are usually die-cast into the rotor slots, which results in a ..Significance of Rotor Slots Number on Induction Motor Operation ..

The following equation defines the tooth or slot pitch of the 15-slot stator. Say.Previously defined is the number of phases, which is three here.

Walker .The power factor and the efficiency are the second best.

SINCE induction motors were

If the number of rotor slots is a multiple of 2 (e.g., 30), then the magnetic flux density would be characterized by both even and odd harmonic rank numbers.The feedback you provide will help us show you more relevant content in the future.Undo Answer Wiki 3 Answers Mihir Parekh, Sub Engineer at Municipal Corporation of Greater Mumbai (2016-present) Answered 82w ago · Author has 409 answers and 241k answer views Reactance, what is it?Q According to my invention, in special highslip machines of the general character hereinabove discussed, I depart from the accepted design-practice of utilizing semiclosed slots in the rotor, and I build my machine with fully open slots in the rotor-core, as well as in the stator-core, however making my rotor slots as narrow as is possible and utilizing unstranded or non-subdivided rotor-conductors, that is, a proportion of the slot-space, which is occupied by the insulation around my rotor-conductors, as compared with the previous practice involving stranded rotor-conductors, and I further increase the heat-flow from each rotor-conductor inboth directions to the two sides of the slot in which it is placed, thus more effectively cooling each rotor-bar. In general two types of stator slots are employed in induction motors viz, open clots and semiclosed slots. The AC induction motor comprises two electromagnetic parts:

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2. Previous work state that motors manufactured with odd rotor slot number are very noisy and have increased mechanical oscillations [ 18 ].
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The early designs were three-phase, later moving to two-phase and then one-phase, due to the very slow start-up requirements, very small friction loads, […] Stator Winding Design Considerations (Electric Motors) TABLE 5.8 Summary of Distribution Factors TABLE 5.9 Summary of Kp and Kd Factors Related Links :: Figure 5.35 shows the winding pattern for a constant-pitch 4-pole 12-slot BLDC stator.There is now only one coil per pole per phase (n = 1) in this winding, as shown in the following equation:

Take Action Report Topic Permalink Printer Friendly Format Original Post electricpete Leader 3/23/08 2:31 PM Last edited by electricpete 3/23/08 2:41 PM Here is a tabulation of rotor bars/stator slots for Reliance NEMA frame motors: 'left', 'opacity':

05 By way of illustration of a practical embodiment of my invention, I have shown an exemplary doubly-fed motor-system in Fig. - Quora 602 × 380 - 11k - webp 1 %PDF-1.5 %յյ 1 0 obj >>> endobj 2 0 obj > endobj 3 0 obj >/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 720 450] /Contents 4 0 R/Group>/Tabs/S/StructParents 0>> endobj 4 0 obj > stream x Electrical Machine Design :

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While the two-layer arrangement of rotorwinding, with two bars per slot, as shown in Fig

1. 247 × 470 - 13k - png circutor.com Slot harmonics in power generation systems 311 × 323 - 14k - jpg slideshare.net Design of stator & rotor for Wound Induction Motor 638 × 359 - 26k - jpg theengineeringprojects..
2. Performance of some magnetic slot wedges in an open-slot induction motor - IET Journals & Magazine The paper presents an experimental assessment of magnetic slot wedges for use in induction motors with open stator slots.
3. The requirements for an ideal magnetic-slot-wedge design are indicated.
4. Construction of this type of rotor along with windings resembles a 'squirrel cage'.3 involved coils having one coil-side lying in the top of one slot, and the other coil-side lying in the bottom of another slot, the four-layer winding of Fig.

Quora Why does a close slot of stator winding have more reactance?

The ysis will reveal that the proper rotor slot number selection has a strong impact on the induction motor performance.5, pp. Since total turns per phase are directly proportional to torque, putting all the needed turns (N per phase) in a single coil with smaller magnet wires and then paralleling the coils will yield extra space for more turns.

It displays the various sta-tor slot and rotor pole combinations along with the maximum number of parallel circuit combinations with a specific slot and pole combination. Personalized Logo Poker Chips The use of FEM offers an insight into the motors' electromagnetic behavior as well as a quantitative representation of their electromagnetic variables and puts the ytical methods under test.

The number of stator slots .. VSP1 = 7 and VSP2 = 5. But avoid … Asking for help, clarification, or responding to other answers.

3 is a corresponding view of a double-layer rotor-slot of my present invention; Fig

Common slots for 2-poles are 18 & 24(fractional hp up to 15hp), 30(usually 10-20hp designs) 36, 48, and 60.A wound-rotor asynchronous machine-hav ing a stator member comprisinga magnetizable core having fully open slots, a polyphase primary winding having pro-formed coils insulated for an operating voltage of more than 2,000 volts and lying in said stator-slots, and a rotor member comprising a magnetizable core having fully open slots, a secondary winding lying in said rotorslots, all 01' the secondary-winding conductors being in good heat-exchanging relation to the operate, for long-sustained side-walls of the rotor-slots, a plurality of sliprings connected to said secondary winding in such manner as to provide polyphase terminals therefor, and circuit-means, associated with the primary winding and with the sllprings, respectively, for causing the motor to operate, for long-sustained periods, at high slip.This is called the rotor Skew. FIGURE 5.34 12-slot lamination, 2 poles, 3-phase constant-pitch lap pattern.1, I have illustrated a variable speed three-phase wound-rotor induction motor or asynchronous dynamo-electric machine i0, having a stator member II and a rotor member l2, the latter being mounted, on a shaft l3 which drives any desired load, such as a fan or blower H.The motor with 40 rotor slots is characterized by the greatest power factor, but by lower efficiency than the motors with 28 and 48 rotor slots.It yields the value of total number of turns—or, more appropriately, conductors—that can be placed in a slot, assuming 100 percent fill. The motor with 41 rotor slots is obviously a motor with odd rotor slot number.

• Frohne, Über die Primären Bestimmungsgrößen der Lautstärke bei Asynchronmaschinen [Ph.D.
• Total conductors (theoretical) = (SA) (turn/in2) Total conductors (theoretical) = 0.2192 x 1410 = 309 (5.12) where SA = slot area The total conductors must be an even number because 2 conductors equal 1 turn.A comparison of Pigs.
• Coils are called "hairpin" coils, meaning that the coils are pushed axially into slots from stator ends (instead of radially placing them into slots).
• Stator slots will usually be a multiple of 6.
• In this respect, the performance of a machine with magnetic slot wedges lies between the performance of the equivalent machines with open and semiclosed slots, respectively.
• Abstract—In this paper, the effects due to the presence of closed or open rotor slots in high-speed induction motors are presented.Slot.
• Degrees electrical = degrees mechanical x number of pole pairs .-.

Stator slot dimensions:

• Electric Machine Design :
• Performance of some magnetic slot wedges in an open-slot induction motor Performance of some magnetic slot wedges in an open-slot induction motor Thank you 1) J.H.Table 1:
• Stator slots will usually be a multiple of 6.
• 5.31a.

The induction motor design is strongly connected to the power 

And each individual term of ( 18 ) is From ( 17 ) and ( 19 ), the space harmonics which depend on the stator and rotor MMF and the rotor and stator slot numbers , are presented, respectively, The equations shown in ( 20 ) offer useful information about the magnetic field's distribution. Axa Kettingslot Openbreken The motor with 24 rotor slots is characterized by the least starting torque, whereas the motor with 30 rotor slots has the greatest.A list of slot & bar combination is attached.

Alger .Design of Induction Motors Why does a close slot of stator winding have more reactance? In this way, I reduce the proportion of the slot-space, which is occupied by the insulation around my rotor-conductors, as compared with the previous practice involving stranded rotor-conductors, and I further increase the heat-flow from each rotor-conductor in both directions to the two sides of the slot in which it is placed, thus more effectively cooling each rotor-bar.Three is selected for the pattern shown in Fig. Maryland Casino Roulette   Get Answer D   165.Motors of the class to which my invention relates are invariably polyphase motors, and motors of a primary-voltage rating higher than 2,000 volts, the primary windings being preformed and insulated before the coil-sides thereof are placed in the primary slots, the insulation being adapted, of course, to the rated line-voltage of over 2,000 volts. Little River Casino Bands