Design Optimization of Protection Layout in DC Distribution Grids Based on Column Generation

The complexity of grid planning processes increases with rising challenges and solution options. DC distribution grids represent one solution option for the future, for which several design decisions are open. One is the complex problem of protection layout, i.e. where to place DC circuit breakers within the grid. For this application case facing the trade-off between cost and higher selectivity, the potential of a column generation optimization method is investigated in this paper. In this context, a column generation framework is set up and master and pricing problems for the optimization of protection layouts in DC grids of various topologies are developed. Due to the complex problem structure, several non-exact pricing problems are combined. The methodology is applied to a meshed 170-bus medium-voltage DC grid. The results indicate that a flexible and efficient approach for protection layout optimization has been developed.