Question 14.2: FINDING THE PERFORMANCE OF A SEPARATELY EXCITED MOTOR WITH A...
FINDING THE PERFORMANCE OF A SEPARATELY EXCITED MOTOR WITH A STEP CHANGE IN LOAD TORQUE CONTROLLED BY A DC–DC CONVERTER
Use PSpice to plot the transient response of the motor speed of Example 14.1 if the load torque T_{L} is subjected to a step change as shown in Figure 14.5.
The PSpice schematic is similar to that shown in Figure 14.2, except that the load torque is a step pulse from 50 msec to 250 msec as shown in Figure 14.6. The listing of the circuit file is as follows:
Example 14.2 DC separately excited motor with step load torque change
| SOURCE VS 1 0 DC 220V ; Armature supply
.PARAM Duty_a=0.5 ; duty cycle of the armature circuit Vg1 6 0 PULSE (0 20V 0 1ns 1ns { {Duty_a}/{Freq}-2ns} CIRCUIT . PARAM VISCOUS = 0.3 J = 0.2 TL_min=150 TL_max = 250 S1 1 2 6 0 SMOD ; Voltage-controlled switch ANALYSIS .TRAN 10US 90MS UIC ; Transient analysis with initial condition . END |
The plots of the transient response of the load torque V(14,13) and the motor speed V(17) are shown in Figure 14.7. As expected, as increase in load torque slows down the speed rise.
