future scope of four quadrant motor operation

[Guest]

pls tell me future aspects of 4 quadrent motor operation and it's control

[dhanabhagya]

Four Quadrant Operation
Motor is driving a hoist consisting of a cage with or without load, a rope wound on to a drum to hoist the cage and a balance weight of magnitude greater than that of the empty cage but less than that of the loaded cage.

The arrow in the figure indicates the actual directions of the motor torque, load torque and motion in four quadrants.

The load torque of the hoisting mechanism is of active type and assumed to be constant due to negligible friction and windage for low speed hoist.

Speed torque curve of the hoist is represented by vertical line passing through two quadrants. Loaded hoist characteristics in first and fourth and unloaded in second and third quadrants.

In the first quadrant the load torque acts in the opposite direction to that of rotation. Hence to drive the loaded hoist up, the motor developed torque must be in the direction of the rotation or must be positive. The power will also be positive so, this quadrant is known as ‘forward motoring quadrant’.