the power input of a 3 phase induction motor is 50kw and corresponding stator losses are 2kw.Calculate total mechanical power developed and rotor copper loss at slip of 3 percent.
Answers
step-1: Input power to rotor = stator input power - stator losses
= 50 kW – 2 kW = 48 kW
Slip = rotor copper losses / rotor input.................(equation-1)
slip = 3% (given)
so, put the value of slip and rotor input in equation-1 , we get
0.03 = rotor copper losses/ 48 kW
rotor copper losses = 0.03 * 48 kW = 1440 watt or 1.44 kW
Step-2: Total mechanical power developed by the rotor
= rotor input power – rotor losses
= 48 – 1.44 = 46.56 kW
so, Total mechanical power developed by the rotor is 46.56 kW
Given:
The power input of a 3 phase induction motor is 50kw and corresponding stator losses are 2kw.
To find:
Calculate total mechanical power developed and rotor copper loss at slip of 3 percent.
Solution:
The formulae used as follows.
The I/n power to rotor = stator input power - stator losses
= 50 kW – 2 kW = 48 kW
Slip = rotor copper losses / rotor input
3 % = rotor copper losses / rotor input
0.03 = rotor copper losses / 48 kW
The rotor copper losses = 0.03 × 48 kW = 1440 watt or 1.44 kW
The total mechanical power developed by the rotor
= rotor input power – rotor losses
= 48 – 1.44 = 46.56 kW
The total mechanical power developed by the rotor is 46.56 kW
Therefore, total mechanical power developed is 46.56 kW and rotor copper loss at slip of 3 percent is 1.44 kW