Early Detection of Voltage Instability in Distribution System utilizing Phasor Measurement Units
DOI:
https://doi.org/10.24084/repqj08.560Abstract
Power system automation leads to a great jump in
detecting and solving the system problems. Due to the serious
problems of system voltage collapse, an early prediction online
voltage instability detector is discussed in this paper. The
voltage instability detector utilizes the voltage and current
phasor readings of connected phasor measurement units to the
distribution terminals. The detector works according to two
parallel algorithms. The first algorithm is a comparison for
terminal current and voltage phasors with an offline calculated
Look-up table, in which particle swarm optimization technique
is used. The Look-up table represents the permissible maximum
current and minimum voltage phasors for each terminal. The
second algorithm is based on the online computation of the ratio
of the Thevenin equivalent system impedance to the terminal
load impedance. The simulated voltage detector is applied to
two different unified power systems. It gives good and
reasonable results.