AC Synchronous Reluctance motors

AC Synchronous Reluctance Motors

Invented many years ago but developed for production in series only recently the Synchronous reluctance motorscombine the advantage of the robust and simple design typical of the asynchronous motors with the performances and high efficiency of the Permanent magnets motors.

• Most of the components used for the stator, shields, ventilation and all the minor components are the same as the ones used for the production of the Asynchronous motors.

• The performances of the QSR motors (Square SRM) are higher than the IEC motors if compared with the same frame size, giving evident advantages in terms of dynamic and installation volume.

• Magnetic design is optimized only for inverter duty operation, DOL is not permitted.

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Description

WHAT is a SYNCHRONOUS RELUCTANCE motor ?The SYNCHRONOUS RELUCTANCE MOTOR is an electrical rotating machine thatconverts the electrical power into mechanical power.

As construction and production process the SRM is similar to all the Asynchronousmotors. Only the rotor design has significant difference, SRM rotor is anisotropic (notsymmetrical)

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The rotor hasSeverallidentical slots, with samedimensionsand shape and symmetricallydistributed .

The rotor hasIdenticalsectors withseverall diferentslots, withdifferentdimensions and shape and notsymmetricallydistributed .

Description

Why SYNCHRONOUS RELUCTANCE motor ?

Synchronous:because when rotating the rotor mechanical speed is exactly in synchronism with the rotatingmagnetic field.

Reluctance: because the magnetic design of the rotor hasareas of high RELUCTANCE (white areas, air) and areas of low RELUCTANCE (blue areas, iron).

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AIR, high Rel. IRON, low Rel.

Description

What is the reluctance:

The RELUCTANCE is a magneticresistance and is the opposite of the permeance.The rotor reluctance depends fromthe “empty” areas present on the rotor laminations that creates a kindof magnetic barrier where the fluxfind high “resistance” to flow.

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Description

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How does it function !

When the stator windings are excited a magneticfield is generated and the rotor aligns its mostmagnetically conductive axis (d-axis) with the applied field in order to minimize the reluctancein the magnetic circuit.

The Synchronous Reluctance motors are engineered intentionally with rotors made with“identified” sectors (depending of the nr. of poles) and are made with magnetically conductivematerial (iron) and magnetically insulatingmaterial (air).

Description

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Synchronous Reluctance ROTORMechanical construction of the rotor seems to be quite simple

since does not require aluminium/copper casting or magnetsassembly but its design is complex due to the particular“shape” of the rotor slots that must keep the necessaryrobustness with a minimized connection sectors between the rotor “poles”.

Advantages if compared to Asynchronous or Permanent Magnetsrotors:

• Rotor without permanent magnets.• No fundamental rotor losses (I2R), highest possible efficiency.• No rotor slip (additional losses).• Easy maintenance if compared to PM motors.• “Cold” rotor (low bearing working temperature).

Efficiency

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EfficiencyTipical percentage of the losses for a 55kW motor 4P 1500rpm.

ASM SRM

Stator I2R; 40

Rotor I2R; 25

Core (steel); 20

Stray; 10Friction; 5

Asynchronous - losses %

Stator I2R; 55Core

(steel); 30

Stray; 10Friction; 5

SRM - losses %

Efficiency

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The Synchronous reluctance rotor has not the “short circuit cage” inside and so the rotor losses are not influenced by the Joule effect (I2R rotor).

For this reason the Synchronous reluctance motors are normally called “coldrotor motors”.

ASM SRM

SRM Oemer Production Program

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SRM Oemer Production Program

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Available speed and catalogue dataDATI ELETTRICI E PRESTAZIONI ELECTRICAL DATA AND PERFORMANCES ELEKTRISCHE DATEN UND LEISTUNGEN

QSR nn 580 rpm Un 360Vac

nn 1000 rpm Un 360Vac

nn 1500 rpm Un 360Vac

nn 1800 rpm Un 360Vac

nn 2200 rpm Un 360Vac

nn 2600 rpm Un 360Vac

QSR - IP 54 - IC 416 Motor Pn Kw In A Pn Kw In A Pn Kw In A Pn Kw In A Pn Kw In A Pn Kw In A nmax 2) Mmax J W Type Mn Nm η % Mn Nm η % Mn Nm η % Mn Nm η % Mn Nm η % Mn Nm η % rpm Nm Kgm2 Kg

100S 1,7 4,3 2,8 7,2 4,0 10,0 4,8 12,0 5,6 13,9 6,2 15,5

4400 55 0,022 44 28,0 85,2 26,7 88,7 25,5 91,5 25,5 92,1 24,2 92,1 22,9 92,1

100X 4,7 11,4 7,7 19,3 11,0 27,0 13,2 32,2 15,3 37,3 17,2 42,0 150 0,053 82 77,0 87,8 73,5 91,5 70,0 93,6 70,0 94,1 66,5 94,2 63,0 93,8

132S 4,7 11,4 7,7 19,3 11,0 27,0 13,2 32,2 15,3 37,3 17,2 42,0

3800 150 0,075 94 77,0 87,8 74 91,5 70,0 93,6 70,0 94,1 66,5 94,2 63,0 93,8

132X 10,6 25,4 17,5 42,9 25,0 60,6 30,0 72,4 34,8 84,0 39,0 94,1 330 0,150 157 175 89,8 167 93,5 159 94,7 159 95,1 151 95,1 143 95,1

160S 12,8 30,4 21,0 51,5 30,0 72,4 36,0 86,6 41,8 100 46,8 113

3600 400 0,250 201 210 89,8 201 93,5 191 95,0 191 95,4 181 95,4 172 95,4

160P 23,4 55,1 38,5 93,4 55,0 132 66,0 158 76,6 183 86 205

730 0,390 276 385 90,8 368 94,6 350 95,8 350 96,1 333 96,0 315 96,0

180S 23,4 55,1 38,5 93,4 55,0 132 66,0 158 77 183 86 191

3300 730 0,59 415 385 90,8 368 94,6 350 95,8 350 96,1 333 96,0 315 96,0

180P 46,8 109,4 77,0 185 110 262 132 313 153 365 172 381

1450 0.92 580 770 91,6 735 95,4 700 96,4 700 96,6 665 96,4 630 96,3

225S 46,8 109,4 77,0 185 110 262 132 313 153 340 172 381

3000 1450 1,25 730 770 91,6 735 95,4 700 96,4 700 96,6 665 96,4 630 96,3

225X 76,6 179 126 303 180 427 216 512 251 556 281 622 2400 2,00 1050 1261 91,5 1203 95,3 1146 96,6 1146 96,8 1089 96,6 1031 96,6

280S 96 222 158 376 225 534 270 639 314 695 351 778

2400 3000 2,70 1230 1576 92,2 1504 96,0 1433 96,7 1433 96,9 1361 96,6 1289 96,6

280P 151 351 249 594 355 842 426 1008 495 1096 554 1227

4700 4,20 1830 2486 92,2 2373 96,0 2260 96,7 2260 96,9 2147 96,6 2034 96,6

SRM Oemer Production Program

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More details are available on our webpage, download section.

Thank you