Question 14.4: FINDING THE TORQUE–SPEED CHARACTERISTIC OF AN INDUCTION MOTO...
FINDING THE TORQUE–SPEED CHARACTERISTIC OF AN INDUCTION MOTOR FOR VARYING ROTOR RESISTANCE
Repeat Example 14.3 for rotor resistance R_{r} = 0.1 Ω, 0.2 Ω, 0.3 Ω, and 0.42 Ω. The slip is kept fixed at s = 0.1.
The PSpice schematic is similar to that as shown in Figure 14.9. The rotor resistance is varied by using the PSpice parametric command .PARAM.
The listing of the circuit file is as follows:
Example 14.4 Torque–speed characteristic with variable rotor resistance
| SOURCE VS 1 0 AC 170V ; Input voltage of 170V CIRCUIT .PARAM SLIP = 0.1 ; Slip .PARAM RRES = 0.42 ; Rotor resistance LM 4 0 58.36MH ANALYSIS .AC DEC 100 0.1HZ 100HZ ; AC analysis .OPTIONS ABSTOL = 1.00N RELTOL = 0.01 VNTOL = 0.1 .END |
The plots of the torque developed T_{d}= V(5) × I(Vy)/2/(2 × 3.14 × Frequency) vs. frequency for various slips are shown in Figure 14.11. The torque increases as the rotor resistance is reduced.
