Bulk power system reliability evaluation considering optimal transmission switching and dynamic line thermal rating

Power system operators are faced with the increasingly complicated operating condition of bulk power systems. Due to the huge investment needed to build new power delivery facilities, cost-effective solutions such as new operational strategies are becoming more attractive in the recent years. Optimal transmission switching (OTS) and dynamic thermal rating (DTR) are such cost-effective technologies which offer a potential solution to improving the power system reliability by more fully utilizing the existing power delivery assets. In this paper, these two technologies are discussed, which are then incorporated into the reliability evaluation procedure for the power system. Case studies are conducted on a modified RTS-79 system using MATLAB and CPLEX. The obtained simulation results show that with the enforcement of either OTS or DTR, the overall system reliability can be improved, and system reliability can be further improved if both technologies are enforced.

I. Introduction

With the growth of renewable energy resource integration, system load uncertainties, volatile weather conditions, and so forth, electric utilities are faced with an increasingly complex and uncertain operating environment. Utilities are in need of a series of cost-effective technologies which allow them to operate power systems more economically and reliably. In the past, such technologies are usually considered as too difficult to be implemented. However, with the development of smart grid technologies, they are becoming more and more practical nowadays. Several of these technologies are being actively investigated such as optimal transmission switching (OTS) [1], dynamic thermal rating (DTR) [2], network topology optimization (NTO) [3], and so forth.