Flexible load shedding strategy considering real-time dynamic thermal line rating

In recent years, real-time dynamic thermal line rating (RT-DTLR) technology has been developed and implemented in operations to improve transmission line capacity, so that congestion costs and/or risk of load shedding can be reduced. Power systems obviously benefit from this technology but also bear the risks because of thermal overload of transmission lines. To involve RT-DTLR technology into conventional power system load shedding strategies, this study explains the concept of flexibility in power system analysis, expresses transmission line capacity constraints into flexible forms and proposes a flexible load shedding strategy considering RT-DTLR. The two sub-objective functions, representing load shedding quantity and system risk increment, are normalised and expressed as the confidence levels from system security consideration and load loss consideration, respectively. The proposed method takes advantage of both the advanced hardware and software technologies in smart grids and the simulation results showed that it can trade off the benefits and risks brought about by RT-DTLR in load shedding.