Electric Power Generation, Transmission, and Distribution

for soft-starting the synchronous motor or condenser. Special design and control are employed to avert
problems imposed, such as excitation of train torsional natural frequencies and extra heating from
harmonics of the supply power.

TIME (SECOND)

CURRENT (PU)

GAP TORQUE (PU)

SPEED (%)

0.0

−10.0

−8.0

−6.0

−4.0

−2.0

0.0

2.0

4.0

6.0

−3.0

−2.0

−1.0

0.0

1.0

2.0

3.0

4.0

0.0

20.0

40.0

60.0

80.0

100.0

1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0

FIGURE 5.6 Synchronous motor and condensor starting.