Effects of network unbalances and their solutions in resonant grounded power distribution systems

This paper investigates the effects of network unbalances
and proposes solutions to mitigate the effects for resonant
grounded power distribution systems (RGPDSs). The effects of
network capacitive unbalances are analyzed to investigate their
sensitivities on the neutral voltage. The effects on the neutral
voltage are minimized by controlling the unbalances. In this paper,
a network balancing technique is developed which has the ability
to optimally select reactance from distributed capacitor banks
across different sections. The capacitors are selected in such a
way that the residual currents are minimum at the substation,
feeders, and sections. A weighted sum method is used in this
paper to determine the optimal settings of the capacitor from
variable capacitor banks with the primary objective to minimize
the residual current at the substation along with two secondary
objectives, i.e., minimizing the same for feeders and sections.
Simulation studies are carried out to demonstrate the effectiveness
of the proposed scheme in comparison with the system having
a centralized capacitor bank. The performance of the proposed
scheme is also evaluated for the scenario when the network
configuration is changed. Simulation results demonstrate that the
proposed technique is capable to limit the network unbalance at
the substation, feeders, and sections.