Simulation of substation grounding grids with unequal-potential

A method of forming the equation system for simulating substation grounding grids with unequal-potential, i.e., the potential drop caused by the inter ior resistance of conductors is taken into account, is presented, based on a theory of combination of field and circuit. The equation system with the potential at discretization points of the grid as unknowns is formed by the method of node analysis in the circuit theory, and the definition of the m utual-resistance between conductors located in conducting media concerns wi th the electric current field theory. The method presented is capable of ca lculating the grids with arbitrary structure and floating electrodes in mul tiple-laver earth models. Comparison of calculation results of grids by equ al and unequal potential models is given.