Abstract:

Current-carrying capacity of transmission lines obtained by setting conservative weather conditions limits the exertion of line heat capacity most of the time. Based on the heat balance equation that reflects the coordination relationship between heat and electricity, the heat capacity of transmission lines was reevaluated from the angle of real-time operation, and the definitions of static thermal rating and dynamic thermal rating were presented. From the standpoint that heat capacity is determined by the conductor temperature and the research clue that the temperature and power system operation dispatch are interlinked, a new concept of advanced thermal rating was proposed and its application foreground was expatiated by examples of advanced dispatch and security dispatch.  The research can provide a foundation for the in-depth research of electro-thermal coordination in dispatch operation of power systems.

Key words: power system; transmission line; advanced thermal rating