Economic Assessment of Fault Current Limitation and Power Flow Control Techniques in Subtransmission Networks

Supplying uninterrupted and high quality electric power to the customer is a priority in the current power systems. Electricity, as a commodity, represents the motive force of modern society and its deprivation causes costly losses for essential parts of the economy in any region. This thesis performs a reliability study on a fictional test network, employing several techniques to control fault current and power flow in meshed 110-kV subtransmission systems. More specifically, this work tests traditional and recent alternatives applied to cases in which underground cables (UGC) and overhead lines (OHL) are installed in parallel circuits for optimized performance. Economic assessment is handled in order to provide the most inexpensive and reliable solutions, accrediting load growth prediction for a review time of 40 years. Moreover, fault analysis and power flow simulations are implemented to confirm efficacy and operational viability under contingency conditions of the chosen techniques and technologies. It is imperative to realize that the simulations and reliability studies were conducted in a simple 4-bar network. However, this simplified model can be adapted to any 110-kV urban subtransmission network without major alterations.