Design of Induction Motor. NEMA Class B, Squirrel-cage Type

Transcription

1 Deign of Inuction Moto NEMA Cla B, quiel-cage Type

2 NEMA Deign Cla National Electical Manufactue Aociation (NEMA) eakown toque: pullout toque locke-oto toque: tating toque

3 NEMA Roto hape Cla B, A Cla C Cla D oule cage

4 Roto Peipheal pee The maximum allowale peipheal pee of the oto i a cental conieation in machine eign. With peent-ay teel alloy, oto peipheal pee of 50,000 ft/min (o aout 50 m/) epeent the eign limit. ft/min = m/ Thi i typically not a polem fo low pee moto.

5 Maximum Flux Expeience fomula i: m ( ) P P : the nume of pole P out : output powe in Watt 0.08 P f out Alo m BmDl P Bm P Dl m

6 Nume of Tun pe Coil on tato E fn eff fn m eff m E X 0.97V, ate (ecaue R an ae mall) whee PqNc kw Neff kw kpkk. The enominato. in N eff D i to conieing leakage flux. N c.07v fpqk ate w m

7 tato Volume an ize D l T Typically V 3 V0 9 ~ 0 in /(ft l) 3 V0 5 ~ 6 in /(ft l) 0 (contant), V0 fo 0hp o le (ai coole) fo 0hp o moe (wate coole) The unit fo D an l i inch. If we eign D=l, we have the tato oe (inne) iamete etimate J D etimate (TV 0 ) epen 3 on cooling

8 Fame Diamete Etimation Etimate tato Coe iamete (oute iamete):.03 D0, etimate (.75 ) Detimate P inch Etimate fame outie iamete: D t f, etimate D0, etimate f t f i wall thickne, typically 0.5 inch D f i picke up fom NEMA fame

9 NEMA tana Fame ize (inch)

10 tato Boe Diamete an Length Fame outie iamete: D f i picke up fom NEMA fame in lat page. tato Coe iamete (oute iamete): D D f t D 0 t f i wall thickne, typically 0.5 inch tato Boe iamete (inne iamete): tato active egion length: D inch P l TV D 0 f

11 Expeience fomula g D 0.00l Ai Gap inch D D g Effective aigap g eff k c k c g whee the Cate coefficient k c (5 g (5 g ) ) k c (4.4 g 0.75 (4.4 g 0.75 ) ) NEMA Cla B

12 tato lot Deign D 0.7in.5in t Ue 0.05-in coil epaato an lot line fo 30V moto Ue in coil epaato an lot line fo 460V moto NEMA 84T o malle fame: ue 0.06 in lot wege Lage than NEMA 84T fame: ue 0.5 in lot wege,

13 tato Conucto ize tato cuent enity J a I, ate A a whee A a i tato (amatue) conucto co ection aea an can e etemine fom the aove fomula togethe with: I Ai, ate - coole : A P 3V a out, ate I 400A/cm / pf, ate J a J a 800 A/cm Typical Efficiency : 75% fo P out = -5 hp 85% fo P out = 5-40 hp 90% fo P out = hp

14 Nume of lot (Ba) on Roto Cetain nume of lot (a) mut e avoie ecaue they can pouce etimental cup in the pee-toque cuve. ( k (k ) P 3kP,,3...)

15 Roto Effective Wining Facto Roto Coil pitch in electical angle: fix( / P) / P Roto lot pitch in electical angle: P k w k p k P kew, kewe angle in electical aian: i the nume of lot kewe, kew, k typically k p in k q in( ) q k inc ( ) 3P q in( )

16 Effective Nume of Tun pe UCF Phae fo Roto Effective nume of oto lot pe phae (may not e intege) 3 Unlike the tato, the ingle cage oto ha only one conucto pe lot (o equivalent to ingle laye wining). N eff k 6 w

17 Roto Ba ize Rate cuent in oto a UCF I N eff, ate I, ate Neff Roto a cuent enity, J (tanfome elationhip) I ate whee i oto a co ection aea an can e etemine fom the aove fomula togethe with: Ai - coole : 700A/cm J 775 A/cm Roto a can opeate at highe tempeatue than tato. I, ate J

18 Roto lot Deign (NEMA B) 6 4 ~ with atio : epth to w inch D Aea i c c ( ) c w w c ) ( N D t N D t

19 Roto En Ring

20 Roto En Ring ize Rate cuent in oto en ing UCF P I ing, ate I, ate Roto en ing cuent enity J, ing I ing, ate whee A ing i oto en ing co ection aea an can e etemine fom the aove fomula togethe with: Ai - coole : 775A/cm J, ing A ing 930 A/cm Roto en ing can opeate at highe tempeatue than oto a. A ing I ing, ate J, ing

21 Example Deign a 50 hp, 460 V, 60 Hz, 6 pole, Y-connecte, 75 pm, NEMA Cla B quiel cage inuction moto, pf 0.85 lagging. Pick up: 54 tato lot, 8/9 pitch, no kew on tato 5 oto lot (a), lot kewe Following the note icue, pleae tuy the MatLa coe imdeign.m y youelf.