The full load speed of a three-phase four-pole 50Hz, 160kW induction motor is 1,475rpm. The starting...

The full load speed of a three-phase four-pole 50Hz, 160kW induction motor is 1,475rpm.
The starting torque is 170%, the yield torque is 280% of the rated torque,
and the moment of inertia of the rotor is 2.5kg-m ^ 2.
The torque of the load converted to the motor shaft is 800 N-m at full load speed
and the moment of inertia is 20 kg-m ^ 2.

a) Find the starting time when the load torque is assumed to be constant.
b) Find the start time assuming load torque is proportional to speed.
c) Find the starting time assuming load torque is proportional to the square of the speed.
d) Find the starting time when the load torque is assumed to be pure inertia with zero.

answer -
a) 2.7sec
b) 2.0sec
c) 1.9sec
d) 1.7sec

Expert Solution

Manojponduru answered 6 months ago

A 6-pole and three-phase induction motor has synchronous speed of (1000) RPM. a) Find the no-load...

A 6-pole and three-phase induction motor has synchronous speed of (1000) RPM. a) Find the no-load and full-load operating speed of motor for the cases given, 1. 2.5Hz electrical frequency of rotor for no-load condition. 2. 6.3Hz electrical frequency of rotor for full-load condition. b) Find the speed regulation of motor by using parameters found above. c) Determine the electrical frequency of rotor under full-load condition so that speed regulation would be equal to 5%? (Electrical frequency of rotor for...

A 400V, three phase, 50Hz, 4 pole induction motor is operating at a per unit slip...

A 400V, three phase, 50Hz, 4 pole induction motor is operating at a per unit slip of 40KW from the suppply. Under these conditions stator losses amount to 2.2 KW and rotational losses due to friction and windage amount to 1.4KW. Calculate the net horsepower and torque developed.

For full load operation of 60Hz, 380V, 4 pole 30kW induction motor, the speed is 1746rpm,...

For full load operation of 60Hz, 380V, 4 pole 30kW induction motor, the speed is 1746rpm, input current 56.2A power factor 90%. In no load operation, input current 17.3A, power factor 13.5%. In full load operation, assume that the mechanical loss is 25% of the total loss and no other losses. a) Iron loss load efficiency b) Find a rotor copper loss under full load c) Iron loss d) Find a fixed automatic hand under full load e) Find the...

A 6-pole, 50 Hz, 3-phase induction motor running on full load develops a useful torque of...

A 6-pole, 50 Hz, 3-phase induction motor running on full load develops a useful torque of 160 Nm when the rotor emf makes 120 complete cycles per minute. The windage and friction loss is 1005.30 Watt. It is assumed; the core loss is lumped together with the windage and friction loss. The total stator loss is given to be 800 Watt. Compute: a) Shaft power output, b) The copper loss in the rotor winding,c) The input power to the motor, and d) The...

A three phase 10kW, 1700rpm, 60Hz, four poles, Y connected induction motor has a no-load speed...

A three phase 10kW, 1700rpm, 60Hz, four poles, Y connected induction motor has a no-load speed of 1750rpm. The rotational mechanical losses are constant and equal to 500W. The core losses are constant and equal to 300W. The copper losses in the stator equal to the copper losses in the rotor at full load. If the rotor resistance per phase is 0.25?, calculate the following: a.The frequency of the induced current in the rotor circuit at full load. b.The percentage...

A4-pole,250V, 50Hz single phase induction motor has rotor frequency 2 Hz, in starting has following parameters:...

A4-pole,250V, 50Hz single phase induction motor has rotor frequency 2 Hz, in starting has following parameters: main winding Rm=2 Ω ,Xm=4 Ω and staring winding : Rs =4 Ω , XLS=2 Ω ,Xcs=8 Ω. Find : speed of motor, Im , IS, θm θs, α and p.f.

A 400 V,50 Hz, six-pole three-phase induction motor drives a constant load of 140 N.m. The...

A 400 V,50 Hz, six-pole three-phase induction motor drives a constant load of 140 N.m. The motor has the following parameters ?1=0.294 Ω ?1=1.39 ?? ??=41 ?? ?2′=0.156 Ω ?2′=0.74 ?? 1) Starting. Calculate the following: i) Motor starting current. ii) Motor starting torque. 2) Maximum operating point. Calculate the following: i) Slip at which maximum torque is developed. ii) Maximum torque developed. 3) Steady-state operation. Calculate the following: i) Motor slip. ii) Motor speed. iii) Motor current. iv) Motor...

A 400V, 2 pole, 50 Hz, three-phase induction motor is drawing 60 A at 0.85 PF...

A 400V, 2 pole, 50 Hz, three-phase induction motor is drawing 60 A at 0.85 PF lagging. The stator copper losses are 2 kW, the stator core losses are 1.8 kW and rotor copper losses are 700 W. The friction and windage losses are 600 W, the stray loss 100 W, and rotor core loss 100 W. Find the following quantities: a. The air gap power. b. The developed mechanical power. c. The output power. d. The efficiency of the...

Q3). A 10KW, 415V, 50Hz, 4 pole, Y (star)-connected induction motor is running at 1425 rpm...

Q3). A 10KW, 415V, 50Hz, 4 pole, Y (star)-connected induction motor is running at 1425 rpm and is delivering full load output while operating at 89% efficiency. a) Find the total losses of the motor [4 marks] b) If the Copper loss, Core loss and Rotational loss are at a ratio of 1:0.7:0.2, find each loss separately [6 marks] c) What is the torque output of the motor? [4 marks] d) If the full load power factor is 0.85, what...

A three-phase, 11.2-kW, 1750-rpm, 460-V, 60-Hz, four-pole, Y-connected induction motor has the following parameters: Rs =...

A three-phase, 11.2-kW, 1750-rpm, 460-V, 60-Hz, four-pole, Y-connected induction motor has the following parameters: Rs = 0.53 Ω, R’r = 0.38 Ω, Xs = 1.23 Ω, X’r = 1.45 Ω, and Xm = 25.2 Ω. The motor is controlled by varying both the voltage and frequency. The volts/hertz ratio, which corresponds to the rated voltage and rated frequency, is maintained constant. a) Calculate the maximum torque, Tm and the corresponding speed, ꞷm for 60 Hz and 30 Hz. b) Repeat...

Question