On the use of colours for presenting power system connectivity information

An approach is described in which power system elements can be colored not only with respect to their switch-dependent operating conditions, such as energized or earthed, but also according to the different connectivity units to which they belong. Connectivity units can be nodes, network groups, network districts, and power source groups. Two main issues have to be solved for connectivity unit coloring. First, different colors have to be assigned to neighboring connectivity units. In this way the operator can distinguish at one glance the boundaries of each connectivity unit. Second, modifications caused by switching must be minimized and should reflect the power system changes in a natural way. The task of connectivity unit coloring can be converted to the task of coloring a graph. This enables graph theory to be applied. Algorithms to update graph colors after some vertex-edge changes caused by switch indication changes have never been discussed. Therefore, an innovative update algorithm is provided. Issues in implementing such a power system coloring function within a full graphic-based energy management system are discussed.<>