Multi quadrant Dynamics

multi quadrant Dynamics of Electric Drive

1. 1 Multi Quadrant operation of Hoist load Dr. A. Ravi Professor/EEE FRANCIS XAVIER ENGINEERING COLLEGE TIRUNELVELI- India

2. Four Quadrant Operation  of any drives or DC Motor means that the machine operates in four quadrants. They are   Forward Braking , Forward motoring Reverse motoring Reverse braking .   2 Four Quadrant Operation

3.  m T e T e  m T e  m T e  m  T Direction of positive (forward) speed is arbitrary chosen Direction of positive torque will produce positive (forward) speed Quadrant 1 Forward motoring Quadrant 2 Forward braking Quadrant 3 Reverse motoring Quadrant 4 Reverse braking 3 Multi Quadrant operation of Motor using Hoist load

4. 5 The electrical machine in this case is operating as a motor. The flow of power is from the machine to the load. 1 st Quadrant (Forward Motoring): The torque and speed of the motor are in the same direction. Of course, the load torque is opposite to the machine torque.

5. 6 The machine then receives mechanical energy, converting it in to electrical energy and returning it back to the electric source. The electric machine is thus acting as a Generator. 2 nd Quadrant (Forward Braking): The speed direction is unchanged while the direction of the torque is reversed.

6. 7 The machine then receives mechanical energy, converting it in to electrical energy and returning it back to the electric source. The electric machine is thus acting as a Generator. 2 nd Quadrant (Forward Braking): The speed direction is unchanged while the direction of the torque is reversed.

7. 8 Since the torque and speed of the machine are in the same direction, the power flow is from the machine to the load. The machine is therefore acting as a motor rotating in the reverse direction to the speed of the first quadrant. 3 rd Quadrant (Reverse Motoring): The speed direction is unchanged while the direction of the torque is reversed.

8. 9 Since the torque and speed of the machine are in the same direction, the power flow is from the machine to the load. The machine is therefore acting as a motor rotating in the reverse direction to the speed of the first quadrant. 3 rd Quadrant (Reverse Motoring): The speed direction is unchanged while the direction of the torque is reversed.

9. 10 From the load perspective, the load torque and the speed are in the same direction. Hence the power flow is from the load to the machine. 4 th Quadrant (Reverse Braking): The torques remains unchanged as compared to the first quadrant. The speed, however, changes the direction. The machine is in this case acting as generator delivering the electric power to the source.

10. 4 th Quadrant (Reverse Braking): The first and fourth quadrant of operation can be explained with the elevator . When the elevator is going upward or downward, the direction of the load torque remains unchanged but the direction of the speed only reversed. 11

11. 12 Function Quadrant Speed Torque Power Output Forward Motoring I + + + Forward Braking II + - - Reverse Motoring III - - + Reverse Braking IV - + - Multi quadrant operation of drive

12. 13 Applications of Four Quadrant Operation Compressor, pump and fan type load requires operation in the I quadrant only. As their operation is unidirectional, they are called one quadrant drive systems. Transportation drives require operation in both directions. If regeneration is necessary, application in all four quadrants may be required. If not, then the operation is restricted to quadrants I and III, and thus dynamic braking or mechanical braking may be required. In hoist drives, a four-quadrant operation is needed.

13. THANK YOU 14