Reference no: EM132528518

Electrical Drives and Control Assignment -

Q1. A weight of 500 kg is being lifted up at a uniform speed of 1.5M/S by a winch driven by a motor running at a speed of 1000 rpm. The moments of inertia of the motor and winch are of 0.5 and 0.3 kg-m² respectively. Calculate the motor torque and the equivalent moment of inertia referred to the motor shaft. In the absence of weight motor develops a torque of 100 N-m when running at 1000 rpm.

Q2. A motor load system has following details: Quadrants I and II, T = 400-0.4N, N-m; where N is the speed in rpm. Motor is coupled to an active load torque Tl = ± 200 N-m. Calculate the motor speeds for motoring and breaking operations in the forward direction. When operating in quadrants III and IV, T = -400-0.4N, N-m. Calculate the equilibrium speed in quadrant III.

Q3. A motor is required to drive the take up roll on a plastic strip line. The mandrel on which the strip is wound is 15 cm in diameter and the strip builds up to a roll 25 cm in diameter. Strip tension is maintained constant at 1000 N. The strip moves at a uniform speed of 25 M/S. The motor is coupled to a mandrel by a reduction gear with a = 0.5. The gears have an approximate efficiency of 87% at all speeds. Determine the speed and power rating of the motor required for this application.

Q4. An electric motor has a directly coupled load. Torque- speed characteristics of motor and load are

T = 0.5 + 2 ω_m

T_L = 1.2 ω_m²

Find operating speed & discuss the stability.

Q5. A motor equipped with a flywheel has to supply a load torque of 600 N-m for 10 sec followed by a no load period long enough for the flywheel to regain its full speed. It is desired to limit the motor torque to 450 N-m. What should be the moment of inertia of the flywheel? The no load speed of the motor is 600 rpm and it has slip of 8% at torque of 400 N-m. Assume the motor speed-torque characteristics to be a straight line in the range of operation. Motor has moment of inertia 10 kg-m².