Abstract:
Voltage fluctuations leading to lamp flicker that originate
in one place in a power system tend to propagate to other parts
of the network with some level of attenuation depending on the
network impedances and the loads connected. Numerous subsynchronous-
type frequency components exist in these voltage fluctuations
that are responsible for lamp flicker. The rudimentary theory
and the experimental measurements support the idea that industrial
load bases, which contain a large percentage of mains-connected
induction motors, tend to attenuate flicker better compared
to residential load bases having mainly passive loads. This paper
reports on the response of three-phase induction motors of several
sizes when subjected to low-frequency voltage fluctuations: 1)
the case where a balanced single-frequency component is superimposed
on the mains voltage and 2) the case where the mains voltage
is sinusoidally amplitude modulated, a scheme that is frequently
used in the flicker-related work. Small-signal models are presented
that will enable systematic understanding of the behavior which is
verified using large signal models
