Two-layer path searching method
The restoration path searching problem is a typical combinatorial
optimization problem, and it can be resolved by graph theory.
The energized network can be regarded as the start vertex, and the
target vertex is decided by the above-mentioned three-stage
restoration strategies, then the shortest path can be obtained with
graph theory. However, this method gets a combination explosion
in a large-scale power system, a two-layer path searching method
based on Dijkstra algorithm is proposed in this paper. This
algorithm can reduce computation burden and improve searching
speed. It includes inner-layer path searching and outer-layer path
searching. The inner layer is composed of equipment within substations
and power plants, and the outer layer consists of transmission
lines, terminals of substations and power plants. The terms of
graph theory for path searching are tabulated in Table 1. And after
the definitions, the shortest path searching begins with the innerlayer
path searching, the shortest path between any two vertices
within substations or power plants can be obtained by Dijkstra
algorithm. Combined with the results of inner-layer path searching,
outer-layer path searching proceeds outside substations and
power plants, the inner layer is unnecessary to be considered in
the outer-layer path searching process.