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.