Electric drives ?

A dc separately excited motor has an armature resistance of 0.1 Ω. The motor is driven by a 3-phase fully controlled converter connected to a 3-phase 240 V ac supply. The motor is used to drive a hoist which is unidirectional torque load. In the upward direction, the motor lifts a mass of 2260 kg at a constant speed of 2.0 m/s. In the downward direction, the same mass is lowered at a constant speed of 0.5 m/s.

1.Neglecting gear losses, calculate the value of the motor back emf E during the upward motion if the armature current  is 150 A.

2.Calculate the triggering angle required for the upward motion.

The operator during the upward motion changes the triggering angle to keep the motor at holding position. Calculate the triggering angle.

3.Calculate the triggering angle required for the downward motion.        

1 Answer

  • 2 months ago

    This sounds like a fun problem. I certainly hope you have fun doing it correctly. It may be on the Test.

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