J. Bendl et L. Schreier, TORQUE AND CURRENT STRESS OF A 3-PHASE INDUCTION-MOTOR DUE TO NONSIMULTANEOUS SWITCH-ON, Electric machines and power systems, 21(5), 1993, pp. 591-603
The paper discusses the ways for affecting the current and torque surg
es originating due to non-simultaneous switch-on of feeding phases to
a 3-phase induction motor. Here, the non-simultaneous switch-on is def
ined to be that during which at first two phases are switched on (at a
n instant defined with respect to the time course of voltage) and only
then, with some delay, the switch-on of the third phase follows. The
paper demonstrates that -when compared to a simultaneous switch-on of
all 3 phases- proper control of non-simultaneous switch-on as defined
above can reduce both the motor impact stress and the current surges s
ubstantially. However, unproper successive switching-on may increase t
hese unwanted phenomena. First, the present contribution brings an ana
lytical solution for current and torque at zero revolutions and then,
in the latter part, the influence of the controlled switch-on motor st
art is discussed.