`Decoupled method´ for studying large interconnected grounding systems using microcomputers. II. Utilization on Itaipu ground system and complementary aspects

For pt.I see ibid., vol.3, no.4, p.1536-44 (1988). The decoupled method described in part I is used to study the important facilities of the ground system of Brazil´s Itaipu generating complex (13000 MW), including four large nearby substations, interconnected by the aluminium-cable steel-reinforced (ACSR) ground-wires of several 500 kV and 220 kV transmission lines. Of paramount importance was the reduction of ground potential obtained by utilizing ACSR ground-wires. A theoretical justification is presented for the decoupling technique used. It is shown that the subdivision of the fault current into components (self-neutralized and nonneutralized) together with the concepts of virtual circuit and real circuit used in the method are powerful analytical tools for dealing with the design and performance of ground systems