Abstract:
currently there is a growing interest in
load modeling. This has gained momentum globally
as an area of research by power industry engineers
and academic researchers. The interests have been
in the simulation of voltage stability and planning
by utilizing static loads to represent the relationship
between power and voltage. As, most load of the
power systems are dynamic, there is need to
diversify the study to capture dynamic load
characteristics from the measured voltage
disturbance.
It is a reality that, load representation that
contributes significantly to voltage instability of the
power system has received relatively less attention
and continues to be an area of greater ambiguity.
Therefore, there is a need for studies in power
system load modeling and analyze their
characteristics both under steady state and dynamic
performance.
The paper proposes to solve the load flow
equations of a power system with DigSilent
induction motor (IM) models whose active and
reactive power are estimated at each iteration.
Simulations were carried out to demonstrate the
effects of small and large faults in the system on the
induction motor loads. In addition, the dynamic
behavior of the IM with reference to various
parameters was investigated. The results include
system responses to sudden load changes and 3-
phase faults. The simulation results indicate that the
effect of the load model and their aggregation on
system performance is reasonable and practical. It was also found that, representing the system loads
by a single dynamic equivalent load reflects the
actual stability of the power system. However,
representing these loads by constant impedance load
gives false indication of the system stability under
dynamic behavior.
