Tabu search based topology modification for reduction of fault current level in power systems

The paper discusses topology optimization for reduction of fault current level. The problem of excessive fault current level for heavily looped power systems needs to be dealt with in the system long-term planning stage by the change of circuit breakers with higher short-circuit capacity. In the operation planning stage, however, alternative measures should be devised to reduce fault current level for critical locations. In this paper, the countermeasures of interest are bus splitting and line opening which modify power network topology. When the selected measures are applied, the magnitudes of Thevenin impedances at the critical locations would be increased and hence the fault current levels might get lower to the acceptable level. In this paper, a Tabu search on the solution space with binary variables was adopted as the solution technique to find adequate topology changing schemes to satisfying the fault level security criteria.