Answer / daneshwar sahu

Calculation table for slip ring induction motor used for crane hoisting application
Calculation table for slip ring induction motor used for crane hoisting application


Result contain approximate values for cross-checking only
INPUTS
Power Rating
P2
100
HP
Speed
N
980
RPM
Stator Voltage
E1
415
V
Stator Current
Is
138
A
Rotor Voltage
E2
380
V
Rotor Current
I2
124
A
Synchronous Speed
Ns
1000
RPM
Frequency
f
50
Hz
No.of Steps in Speed Control
n
5
OUTPUTS
Slip
S=(Ns-N)/Ns
0.02
Rotor Frequency
f'=Sf
1
Hz
I2= (SE2)/(√(R22 (SX2)2)
For maximum starting torque application S=(R2/X2)= 0.02
Then R2= 0.02 X2 (Approx.)
From above two Equations we get

Rotor Reactance
X2
2.166940136
Ohm
Rotor Resistance
R2
0.043338803
Ohm

Starting Rotor Current I2s=(E2)/(√(R22 X22)


Starting Power Factor COSØ2s=(R2)/(√(R22 X22)

Power Factor (FL) COSØ2s=(SR2)/(√(R22 (SX2)2)




Starting Rotor Current














I2s














175.3274198














A
Starting Power Factor
COSØ2s
0.019996001
Power Factor (FL)
COSØ2
0.707106781

T= (60P2)/(2лNs)
T=(KSR2E22)/ (√(R22 (SX2)2)
Smax= (R2/X2)
Tm=(KE22)/ (2X2)
Tstm=(KE22)/ (2R2)



Torque (FL)
T
42747.13376
N-m
Torque constant
K
1.282970635
Maximum Slip
Smax
0.02
Maximum Torque
Tm
42747.13376
N-m
Maximum Starting Torque
Tstm
2137356.688
N-m

Pm=(1-S)P2
Pcu=SP2
Tsh=(60P2)/ (2лN)




Mechanical Power
Pm
73.0786
kW
Cu loss
Pcu
1.4914
kW
Shaft Torque
Tsh
42747.13376
N-m

R1’,R2’,R3’,R4’,R5’- Total resistance per phase in the rotor circuit on the 1st, 2nd, 3rd, 4th, 5th Stud respectively
r1’,r2’,r3’,r4’,r5’- Total resistance of the different steps

R1’=(R2/Smax)
k=(Smax)1/n-1
R2’=kR1’
R3’=kR2’=k2R1’
R4’=kR3’=k3R1’
R5’=kR4’=k4R1’






R1'
2.166940136
Ohm
k
0.376060309
R2'
0.814900178
Ohm
R3'
0.306451613
Ohm
R4'
0.115244288
Ohm
R5'
0.043338803
Ohm
r1’=R1’-R2’=(1-k)R1’
r2’=R2’-R3’=(k-k2)R1’=kr1’
r3’=k2r1’
r4’=k3r1’
r5’=k4r1’





Resistance 1st Step










r1'










1.352039958










Ohm
Resistance 2nd Step
r2'
0.508448565
Ohm
Resistance 3rd Step
r3'
0.191207325
Ohm
Resistance 4th Step
r4'
0.071905486
Ohm

S1=1
S2=k
S3=K2
S4=K3
S5=Smax


Slip 1st Step
S1
1
Slip 2nd Step
S2
0.376060309
Slip 3rd Step
S3
0.141421356
Slip 4th Step
S4
0.053182959
Slip 5th Step
S5
0.02

N1=0
N2=(1-S2)Ns
N3=(1-S3)Ns
N4=(1-S4)Ns
N5=N

Speed 1st Step
N1
0
RPM
Speed 2nd Step
N2
623.9396907
RPM
Speed 3rd Step
N3
858.5786438
RPM
Speed 4th Step
N4
946.817041
RPM
Speed 5th Step
N5
980
RPM

T=(KSR2E22)/ (√(R22 (SX2)2)


Torque 1st Step




T1




1709.20167




N-m
Torque 2nd Step
T2
4534.013993
N-m
Torque 3rd Step
T3
11853.64241
N-m
Torque 4th Step
T4
28167.51282
N-m
Torque 5th Step
T5
42747.13376
N-m

how to understand the controling circuits example star- delta-starter controling daigram please let me know

3 Answers   GMR,

---

why eee branch?

1 Answers   TCS,

---

for a machine R=130 KVA Y=132 KVA B=144 KVA Then what will be the total kva

3 Answers   ABB,

---

in a distribution board,if we have a load and we have selected a cable after making all calcs (Deratings and V.D , ect...) the cable we have selected was 10mm.sq. now, shall the internal cable inside the switchboard should be 10 mm.sq Like the external or it can be Less???? if somebody have an specs or information he can help D:

1 Answers  

---

Why machine give shock

3 Answers   Akij, Bhel,

---

---

why VCB always installed only at HT yards or HT side? suppose if ACB installed at there means, what will be problem?

1 Answers  

---

Can we step up a 230V supply to 400V using a single phase transformer??

2 Answers  

---

Dg pf .71 i am improve pf 0.80 what capacitor connected in dg how?

0 Answers   AVT Natural Products, EMC,

---

Why AC current leads voltage in capacitor and how?

0 Answers   BMB,

---

( Re: WHAT SHOULD BE THE RATING OF MCCB FOR 415V,3Ph,50KVAR CAPACITOR BANK Answer # 1 The capacitor current would be kvar x 1000 / (415 x sqrt3). This would be 70a approx. The MCCB selected should have *atleast 1.4 times this current i.e. 1.4 x 70= 98. So you should choose at least 100 A mccb.) regarding to this answer,i would like to know why the current have to times 1.4 to get the right amphere for the mccb.hows the formula to get the 1.4??tq

2 Answers  

---

what is the value of the earth resistance in mositure place

3 Answers   HCL,

---

cost of operation of which plant is least?

6 Answers  

---