Elementary changes in topology and power transmission capacity can induce failures in power grids

Abstract

In this work, we show that elementary changes in the topology of power grids, like the addition or removal of a single transmission line or the increase of its maximum transmission capacity can cause failures in the network. Also, we show that the probability of the occurrence of these failures can be related to the level of centralization of energy generation and to the nature of the nodes being connected by the transmission line being considered, although the increase in the transmission capacity does not seem to be much affected by the level of centralization. When considering a centralized power grid, that is, one grid whose power is supplied by just a few generators, one must be very careful when contemplating a change between two consumers, being an addition, removal or increase in the transmission capacity of the transmission line connecting them, as there is a considerable probability that this change may cause a failure in the network. In the decentralized power grid, the modification that cause most of the failures in the grid is between a consumer and a generator when the removal or increase in the transmission capacity is being considered. Therefore, one must be very careful when planning an update in an existing power grid or when building a new one as a single modification in the grid may lead the system out of the synchronous state.