Operational and Investment Solutions for Dynamic Line Switching and Rating in Electrical Grid

Abstract

The electricity generation industry is one of the most expensive infrastructures and one of the major sources of greenhouse gas emissions among other industries. A great deal of short-term and long-term decisions have been made to accelerate the transition of the electricity infrastructure toward a more cost-efficient and sustainable industry. This trend leads to future dependencies on both traditional and renewable sources of energy that are naturally disseminated in different geographies and are often far from major energy consumption centers. How to efficiently transmit the diverse and disseminated sources of energy is one of the greatest management challenges in the future smart grids. In this dissertation two new transmission management approaches are developed that can result in the cost-efficient and environmentally-friendly utilization of the dispersed and diverse sources of energy. The first transmission management approach that is proposed in this dissertation is the economic seasonal transmission switching which is an alternative transmission management approach to the hourly-based transmission switching. In the proposed seasonal transmission switching, transmission switching occurs once at the beginning of a time period (season) and then the transmission topology remains unchanged during that period. The proposed seasonal transmission switching model is a large-scale mixed integer programming problem. The objective of the optimization model is to minimize the total energy generation cost over the season subject to loads and reliability requirements. The proposed model is demonstrated on typical power systems where the solutions are analyzed and potential cost savings in each case are reported. The second proposed transmission management approach is the integration of the dynamic rating system with transmission switching to further improve the economics and reliability of power systems and reduce emissions. Seasonal transmission switching requires minor investment costs and therefore those minor investments can be neglected. However, utilizing dynamic ratings needs investments in new equipment. We model the investments in the dynamic rating system as a mixed integer linear program where the transmission switching is allowed. We also explore the effects of the proposed transmission management approaches on the emission reduction.