Analytical Models for Power Networks: The Case of the Western US and ERCOT Grids

The topological structure of the power grid plays a key role in the reliable delivery of electricity and price settlement in the electricity market. Incorporation of new energy sources and loads into the grid over time leads to its structural and geographical expansion. This paper presents an intuitive analytical model for the spatio-temporal evolution of large grids and uses it to understand common structural features observed in grids across America. In particular, key graph parameters like degree distribution, graph diameter, betweenness centralities, eigen-spread, and clustering coefficients are used to quantify the model's benefits through comparison with the Western U.S. and ERCOT power grids. The most significant contribution of the developed model is its analytical tractability that provides a closed form expression for the nodal degree distribution observed in large grids. The discussed model can be used to generate realistic test cases to analyze topological effects on grid functioning and new grid technologies.